Co-reporter:Hui Xu, Bo Yan, Ke Zhang, Jin Wang, Shumin Li, Caiqin Wang, Zhiping Xiong, Yukihide Shiraishi, Yukou Du, and Ping Yang
ACS Sustainable Chemistry & Engineering November 6, 2017 Volume 5(Issue 11) pp:10490-10490
Publication Date(Web):October 12, 2017
DOI:10.1021/acssuschemeng.7b02491
Direct ethylene glycol fuel cells represent promising advanced portable energy storage and conversion devices, which can be well applied to serve as advanced sustainable energy technology to overcome the formidable challenges of ecological crisis and environmental pollution. However, many drawbacks of the newly established catalysts such as poor corrosion resistance and antipoisoning make them exhibit limited electrocatalytic performances. For addressing these issues, we herein combined both morphological and component advantages to engineer an advanced Au–Ag–Cu trimetallic electrocatayst with fascinating hollow nanoflowers structures. By virtue of such unique structure, the as-obtained Au–Ag–Cu hollow nanoflowers displayed unprecedentedly excellent electrocatalytic activity toward ethylene glycol oxidation with the highest mass activity of 5493.4 mA mgAu–1, 5.9-fold enhancement than that of pure Au. We postulate that the strategy and electrocatalysts we engineered in this work will greatly boost the commercial development of fuel cell technologies.Keywords: AuAgCu electrocatalysts; Ethylene glycol electrooxidation; High-performance; Hollow nanoflowers; Long-term stability;
Co-reporter:Cui’e Zou, Beibei Yang, Duan Bin, Jin Wang, Shumin Li, Ping Yang, Caiqin Wang, Yukihide Shiraishi, Yukou Du
Journal of Colloid and Interface Science 2017 Volume 488() pp:135-141
Publication Date(Web):15 February 2017
DOI:10.1016/j.jcis.2016.10.088
In this paper, the spherical Au nanoparticles and 3D flower-like structure graphene were successively deposited on glassy carbon electrode (GCE) (Au/f-GE/GCE) via a facile and two-step electrodeposition method for the detection of nitrite ions (NaNO2). The morphology and composition elements were confirmed by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction measurements (XRD). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to evaluate the electrochemical behaviors of NaNO2 on the as-prepared electrode. Compared to f-GE/GCE and Au/GCE, Au/f-GE/GCE showed a sharp and obvious oxidation peak at 0.78 V. The oxidation peak current of NaNO2 was linearly proportional to its concentration in the range from 0.125 to 20375.98 μM, with a detection limit of 0.01 μM (at S/N = 3). Furthermore, the experiment results also showed that the as-prepared electrode exhibited excellent reproducibility and long-term stability, as well as good recovery when applied to the determination of NaNO2 in pickled pork samples.The spherical Au nanoparticles/3D flower-like graphene was prepared by a facile and low-cost electrochemical method and used for sensitive determination of nitrite.
Co-reporter:Jin Wang;Hui Xu;Shumin Li;Bo Yan;Yuting Shi;Caiqin Wang
Analyst (1876-Present) 2017 vol. 142(Issue 24) pp:4852-4861
Publication Date(Web):2017/12/04
DOI:10.1039/C7AN01561E
Plasmonic photocatalyst has attracted significant attention due to its valuable theoretical study and promising practical applications in solar cells, functional composites, and sensors. Herein, an interesting RGO–C3N4-supported AuAg core–Au shell (AuAg@Au) nanocomposite has been reported. Due to the surface plasmon resonance (SPR) of AuAg@Au and the accelarated electron transfer and separation of charge carriers induced by the fascinating RGO–C3N4 substrate, the newly-generated AuAg@Au/RGO–C3N4 nanomaterials show a strong photo-electrochemical response under visible-light irradiation. The AuAg@Au/RGO–C3N4 photocatalyst demonstrated an excellent photo-electrochemical performance with a broad concentration linear range of 0.064–780.904 μM and a low detection limit of 0.022 μM, high stability, and good selectivity when applied in the determination of dopamine (DA) under visible-light irradiation.
Co-reporter:Hui Xu;Bo Yan;Jin Wang;Ke Zhang;Shumin Li;Zhiping Xiong;Caiqin Wang;Yukihide Shiraishi;Ping Yang
Journal of Materials Chemistry A 2017 vol. 5(Issue 30) pp:15932-15939
Publication Date(Web):2017/08/01
DOI:10.1039/C7TA04598K
Shape-controlled synthesis of self-supported metallic nanocrystals with abundant active surface areas is of vital importance for the design and fabrication of novel outstandingly excellent electrocatalysts. Motivated by this, we herein report our research in the synthesis of self-supported porous 2D AuCu triangular nanoprisms via a facile wet-chemical method. Owing to the attractive 2D triangular structure, bifunctional and electronic effects between Au and Cu, such unique Au1Cu1 nanoprisms exhibited extremely high catalytic activities towards ethylene glycol and glycerol electrooxidation with mass activities of 2873 and 2263 mA mgAu−1, which are 3.0 and 3.9-fold enhancements over those of pure Au (958 and 573 mA mgAu−1), respectively. We trust this strategy may be extended to the syntheses of other multimetallic nanocatalysts with such fascinating nanostructures and the as-obtained porous triangular nanoprisms can be well applied to serve as highly desirable anode catalysts for electrooxidation of ethylene glycol and glycerol.
Co-reporter:Hui Xu;Jin Wang;Bo Yan;Shumin Li;Caiqin Wang;Yukihide Shiraishi;Ping Yang
Nanoscale (2009-Present) 2017 vol. 9(Issue 43) pp:17004-17012
Publication Date(Web):2017/11/09
DOI:10.1039/C7NR06737B
Highly open metallic nanocages represent a novel class of nanostructures for advanced catalytic applications in direct liquid fuels cells due to their specific capability of providing easy access to reactants in both internal and external active sites and also desirable electronic structures for the adsorption of molecules, which render superior catalytic performances. However, to date, the rational design of trimetallic nanocages with tunable compositions remains a challenge. Herein, we demonstrate a facile method combining seed mediated and galvanic replacement for the preparation of unique trimetallic Pd–Au–Ag nanocages catalysts with tunable compositions. A series of controlled experiments reveal that the reaction time plays a crucial role in affecting the morphology of the final product. Importantly, the newly-generated Pd–Au–Ag nanocages are high-performance electrocatalysts for the oxidation of both ethylene glycol and glycerol with mass activities of 7578.2 and 5676.1 mA mg−1, respectively, which are far superior to that of commercial Pd/C. We firmly believe that the strategy and enhanced electrocatalysts developed in this study can be well applied to boost the commercial development of fuel cell technologies.
Co-reporter:Hui Xu;Jin Wang;Bo Yan;Ke Zhang;Shumin Li;Caiqin Wang;Yukihide Shiraishi;Ping Yang
Nanoscale (2009-Present) 2017 vol. 9(Issue 35) pp:12996-13003
Publication Date(Web):2017/09/14
DOI:10.1039/C7NR04409G
One plausible approach to endow nanocrystals with both enhanced catalytic activity and stability for the electrooxidation of liquid fuels is to chemically control the crystal structures of nanoparticles. To date, core–shell and alloy structures have been demonstrated to offer generally two precious opportunities to design highly efficient nanocatalysts for the electrooxidation reaction of organic molecules. We herein combine these two advantages and develop a general method to successfully synthesize hollow AuxAg/Au core/shell nanospheres with a high yield approaching 100% via a combined seed mediated and galvanic replacement method. The results from the electrochemical measurements have revealed that this as-obtained hollow AuxAg/Au core/shell nanosphere exhibited considerably high electrocatalytic performance towards ethylene glycol and glycerol oxidation with mass activity of 4585 and 3486 mA mgAu−1, which were 5.3- and 5.8-fold higher than that of pure Au. We trust this strategy may be extended to the syntheses of other multimetallic nanocatalysts with such fascinating nanostructures and the as-obtained hollow AuxAg/Au core/shell nanospheres can be well applied to serve as highly desirable anode catalysts for the electrooxidation of ethylene glycol and glycerol.
Co-reporter:Hui Xu;Ke Zhang;Bo Yan;Jiatai Zhong;Shumin Li
New Journal of Chemistry (1998-Present) 2017 vol. 41(Issue 8) pp:3048-3054
Publication Date(Web):2017/04/10
DOI:10.1039/C6NJ03773A
In this work, surfactant-free ternary Pt/Ru/Pd networks with tunable ratios have been prepared as anode electrocatalysts for direct methanol fuel cell reactions through a partial galvanic replacement method. Scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to characterize the physical structure and chemical composition of the as-prepared catalysts. The electrochemical performances towards methanol electrooxidation of Pt0.3Ru0.6Pd0.1, Pt0.27Ru0.54Pd0.19, Pt0.32Ru0.64Pd0.04, Pt0.33Ru0.67, Pt/Ru, commercial Pt/C, PtRu/C and Pd/C were evaluated. The results proved that the Pt/Ru/Pd catalysts displayed much larger electrochemically active surface areas and higher current densities as well as superior long-term stability in comparison with the Pt/Ru, commercial Pd/C, PtRu/C and Pt/C catalysts. The enhanced electrocatalytic performances are primarily attributed to the synergistic effect of Pt, Ru and Pd together with the 3D nanostructure. The achievements acquired by this facile synthetic pathway and the prepared catalytic materials in this contribution are beneficial for opening a novel way in tuning 3D multimetallic nanostructures for boosting the development of practical commercialization applications of electrocatalysts for methanol electrooxidation.
Co-reporter:Ke Zhang, Hui Xu, Bo Yan, Jin Wang, Zhulan Gu, Yukou Du
Applied Surface Science 2017 Volume 425(Volume 425) pp:
Publication Date(Web):15 December 2017
DOI:10.1016/j.apsusc.2017.06.270
•Pt/Pb nanodendrites have been prepared by heating in an oil bath for 5 min.•Pt1/Pb1 nanodendrites exhibit enhanced electrocatalytic performance and stability.•The presence of Pb enhance the Pt catalytic activity toward ethanol oxidation.This article reports a rapid synthetic method for the preparation of dendritic platinum–lead bimetallic catalysts by using an oil bath for 5 min in the presence of hexadecyltrimethylammonium chloride (CTAC) and ascorbic acid (AA). CTAC acts as a shape-direction agent, and AA acts as a reducing agent during the reaction process. A series of physical techniques are used to characterize the morphology, structure and electronic properties of the dendritic Pt/Pb nanoparticles, indicating the Pt/Pb dendrites are porous, highly alloying, and self-supported nanostructures. Various electrochemical techniques were also investigated the catalytic performance of the Pt/Pb catalysts toward the ethanol electrooxidation reaction. Cyclic voltammetry and chronoamperometry indicated that the synthesized dendritic Pt/Pb nanoparticles possessed much higher electrocatalytic performance than bulk Pt catalyst. This study may inspire the engineering of dendritic bimetallic catalysts, which are expected to have great potential applications in fuel cells.
Co-reporter:Shumin Li, Hui Xu, Zhiping Xiong, Ke Zhang, Caiqin Wang, Bo Yan, Jun Guo, Yukou Du
Applied Surface Science 2017 Volume 422(Volume 422) pp:
Publication Date(Web):15 November 2017
DOI:10.1016/j.apsusc.2017.05.246
•The flower-like PtAu catalysts have been prepared via a facile approach.•The compositions of PtAu nanoflowers can be easily controlled.•The PtAu catalysts provide ideal electrocatalytic active sites.•PtAu catalysts exhibit greatly enhanced catalytic activity and stability.Designing and tuning the bimetallic nanoparticles with desirable morphology and structure can embody them with greatly enhanced electrocatalytic activity and stability towards liquid fuel oxidation. We herein reported a facile one-pot method for the controlled synthesis of monodispersed binary PtAu nanoflowers with abundant exposed surface area. Owing to its fantastic structure, synergistic and electronic effect, such as-prepared PtAu nanoflowers exhibited outstandingly high electrocatalytic activity with the mass activity of 6482 mA mg−1 towards ethanol oxidation, which is 28.3 times higher than that of commercial Pt/C (227 mA mg−1). More interesting, the present PtAu nanoflower catalysts are more stable for the ethanol oxidation reaction in the alkaline with lower current density decay and retained a much higher current density after successive CVs of 500 cycles than that of commercial Pt/C. This work may open a new way for maximizing the catalytic performance of electrocatalysts towards ethanol oxidation by synthesizing shape-controlled alloy nanoparticles with more surface active sites to enhance the performances of direct fuel cells reaction, chemical conversion, and beyond.Download high-res image (104KB)Download full-size image
Co-reporter:Zhulan Gu, Duan Bin, Yue Feng, Ke Zhang, Jin Wang, Bo Yan, Shumin Li, Zhiping Xiong, Caiqin Wang, Yukihide Shiraishi, Yukou Du
Applied Surface Science 2017 Volume 411(Volume 411) pp:
Publication Date(Web):31 July 2017
DOI:10.1016/j.apsusc.2017.03.190
•Cross-linked Pt-NiO nanochains using seed-mediated growth method are synthesized.•The as-prepared catalysts exhibit higher electrocatalytic activity than Pt/C for MOR.•The Pt-NiO(1:1 by molar) catalyst shows the best electrocatalytic property towards MOR.A simple method was reported for employing NiO nanoparticles act as seeds and then different amounts of Pt2+ were reduced on the NiO nanoparticles, forming a cross-linked Pt-NiO nanocatalysts. These as-prepared catalysts were characterized using different physical-chemical techniques, including X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The results indicate that the morphology of the cross-linked Pt-NiO nanochain was successfully produced regardless of the molar ratio of Pt2+ to NiO precursors. The electrochemical characteristics of Pt-NiO nanochain catalysts were evaluated for the oxidation of methanol as a model reaction, which verify that the Pt-NiO catalysts show enhanced activity and high stability in comparison with the commercial Pt/C catalyst. The optimized ratio of Pt to NiO is 1:1, then tuned by simple adjusting the feed ratio of the precursors as well. The synthesized nanocatalysts will be found the great potential applications as electrocatalysts for fuel cells owe to their enhanced catalytic performance and long-term stability.Download high-res image (117KB)Download full-size image
Co-reporter:Hui Xu, Bo Yan, Ke Zhang, Jin Wang, Shumin Li, Caiqin Wang, Yukou Du, Ping Yang, Shujuan Jiang, Shaoqing Song
Applied Surface Science 2017 Volume 416(Volume 416) pp:
Publication Date(Web):15 September 2017
DOI:10.1016/j.apsusc.2017.04.160
•N-doped graphene supported network-like PdBi catalysts are synthesized.•The PdBi-RGO catalysts are also prepared for comparison.•N-doped graphene is an excellent support to anchor binary PdBi on its surface.•The PdBi-NG catalysts exhibit ultrahigh current density for formic acid oxidation.As advanced electrodes for direct formic acid cells, nitrogen-doped graphene (NG) supported palladium-bismuth nanoparticles have been successfully fabricated through typical wet-chemical method. In studying the effects of NG support on PdBi nanoparticles for the electrooxidation of formic acid, we find that the as-prepared Pd1Bi1/NG network-like electrocatalysts exhibit much higher electrocatalytic activities than the Pd1Bi1/RGO, Pd1Bi1 and commercially available Pd/C catalysts in term of mass activity (1.69, 4.33 and 15.5times higher, respectively). The remarkably enhanced performances are associated with the electron transport between Bi and N, bi-functional effect between Pd, Bi and NG hybrids as well as the well-dispersed network-like structure on the surface of NG. The investigations of PdBi/NG in this work for promoting the electrocatalytic performances and the electron effect between Bi and N will accelerate the development for the field of direct formic acid fuel cells.Download high-res image (147KB)Download full-size image
Co-reporter:Zhulan Gu, Hui Xu, Duan Bin, Bo Yan, Shumin Li, Zhiping Xiong, Ke Zhang, Yukou Du
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2017 Volume 529(Volume 529) pp:
Publication Date(Web):20 September 2017
DOI:10.1016/j.colsurfa.2017.06.044
This work reports a simple method to design and synthesize PdNi nanospheres which supported on Vulcan XC-72R Carbon with NaBH4 as reducing agent at ambient temperature and their superior electrocatalytic activity. The results of electrochemical measurements indicate that the PdNi nanospheres exhibit improved catalytic activity, excellent durability as well as higher long-term stability towards methanol oxidation reaction in comparison with commercial Pd/C catalysts. Furthermore, it is interpreted that the enhanced catalytic performance of the PdNi nanospheres is owing to the electronic effect between Pd and Ni and the spherical shape structure with rough surface. These findings highlighted the significance of precisely synthesizing the Pd/Ni nanospheres supported on Vulcan XC-72R Carbon and their emerging applications as electrocatalysts for direct methanol fuel cells.Download high-res image (263KB)Download full-size image
Co-reporter:Hui Xu, Bo Yan, Ke Zhang, Caiqin Wang, Jiatai Zhong, Shumin Li, Yukou Du, Ping Yang
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2017 Volume 522(Volume 522) pp:
Publication Date(Web):5 June 2017
DOI:10.1016/j.colsurfa.2017.03.015
•Effects of different solvents on the formations of PdAu NNs have been studied.•The interactions between PdAu NNs and different solvents are also investigated.•Polarity and functional groups of solvent affect the properties of PdAu NNs.•The prepared PdAu NNs show superior catalytic activity for EG and isopropanol oxidation.Solvents play a key role in controlling the fabrication and modification of nanoparticles. We herein demonstrated that the dispersibility, stability, morphology and structure of PdAu nanoparticles varied with the polarity, special functional groups and self-properties of solvents. The underlying causes for solvent dependence were attributed to the interactions between the solvent and PdAu nanoparticles coated with PVP. Additionally, in comparison with commercial Pd/C, the obtained PdAu nanowire networks prepared in different solvents exerted considerable high electrocatalytic activity and stability towards ethylene glycol and isopropanol electrooxidation, particular for the PdAu nanowire networks prepared in DMF, which exhibited the well-dispersed nanowire network structure with large quantity of surface active areas, superior electrocatalytic activity together with long-term stability. Our efforts not only highlighted the facile preparations of the effective PdAu nanowire networks for the potential anodic catalysts for the application of fuel cells, but also facilitated the selections of appropriate solvents for preparing valid catalysts.Download high-res image (195KB)Download full-size image
Co-reporter:Hui Xu, Bo Yan, Ke Zhang, Jin Wang, Shumin Li, Caiqin Wang, Yukihide Shiraishi, Yukou Du, Ping Yang
Electrochimica Acta 2017 Volume 245(Volume 245) pp:
Publication Date(Web):10 August 2017
DOI:10.1016/j.electacta.2017.05.146
•The binary PdAu nanoflowers supported by N-doped graphene are fabricated.•The morphology of PdAu/NG is PVP-dependent.•The ultrasonic procedure is crucial for the synthesis of desirable PdAu/NG.•The obtained PdAu/NG exhibit outstandingly high electrocatalytic performances.The design of cost-efficient catalysts for the electrooxidation of small organic molecules are highly desirable for the commercial application of direct fuel cells. Shape-controlled PdAu alloys with N-doped graphene support are highly efficient electrocatalysts for the electrooxidation of ethylene glycol and glycerol in the alkaline media. Impressively, the newly generated Pd1Au1-NF/NG catalysts prepared by a facile ultrasonic-assisted synthetic method in this work exhibit the unprecedentedly high mass activities with 12.8 and 8.7 A mg −1 towards ethylene glycol and glycerol oxidation, which are 10.07- and 12.25-fold enhancements than that of commercial Pd/C catalyst (1.27 and 0.71 A mg −1), respectively. This work may open a new way in enlarging the surface area and ultimately maximizing the electrocatalytic activities by tuning the morphology of metallic alloy and introducing the appropriate catalyst supports.Download high-res image (189KB)Download full-size image
Co-reporter:Hui Xu, Bo Yan, Ke Zhang, Jin Wang, ... Ping Yang
International Journal of Hydrogen Energy 2017 Volume 42, Issue 32(Volume 42, Issue 32) pp:
Publication Date(Web):10 August 2017
DOI:10.1016/j.ijhydene.2017.06.238
•The bayberry-like PtRu alloys have been prepared via an eco-friendly approach.•The morphology and structure of PtRu are PVP-dependent.•The PtRu catalysts provide abundant electrocatalytic active sites.•The bayberry-like PtRu alloys show enhanced catalytic activity and stability.Direct fuel cells have attracted an increasing notice over last decade, while its large-scale commercial development is also seriously impeded by the lack of cost-efficient electrocatalysts. The shape-controlled syntheses of binary Pt-based nanocrystals bounded with abundant surface active areas and tunable atomic ratio have been of vital importance in the fabrication and modification of outstandingly excellent electrocatalysts. Therefore, embodying the morphology advantages and composition effects are significant for synthesizing the cost-efficient electrocatalysts. In view of this, we herein report our efforts for demonstrating an eco-friendly approach to successfully synthesize a novel type of bayberry-like PtRu nanocatalyst with different compositions. Different from some other reported PtRu binary nanostructures, such as-prepared bayberry-like PtRu nanocrystals with rough surface can meet the requirement of both high mass activity and long-term stability, which shed light for the commercial development of direct fuel cells.Download high-res image (363KB)Download full-size image
Co-reporter:Hui Xu, Bo Yan, Ke Zhang, Caiqin Wang, ... Yukou Du
International Journal of Hydrogen Energy 2017 Volume 42, Issue 16(Volume 42, Issue 16) pp:
Publication Date(Web):20 April 2017
DOI:10.1016/j.ijhydene.2017.03.023
•The Pd-Ru-P network catalysts are fabricated under mild reaction conditions.•The prepared Pd-Ru-P catalysts show excellent catalytic activity.•Electronic effects and efficient mass transfer enhance the catalytic performances.•The Pd-Ru-P networks reveal promising candidates for further application in DMFCs.Liquid fuel cells have attracted broad research interests for past several decades, especially for direct methanol fuel cells (DMFCs) because of their compact volume, environmentally benign and easy storage. Exploring cost-effective electrocatalysts toward methanol electrooxidation is meaningful for the development of (DMFCs). Herein, a series of PdRu/P network catalysts have been fabricated and modified via a facile and reproducible method taking benzyl alcohol, hydrazine hydrate as solvent and reducing agents, respectively. Profiting from the 3D network structure, the synergistic effect together with the increased electron mobility induced by the addition of nonmetal phosphorous (P). The PdRu/P catalysts display markedly improved efficient electrocatalytic activity with excellent current peak, more negative onset potential, as well as superior long-term stability compared to commercial Pd/C, PdRu and Pd/P prepared under the same condition. In this work, we highlight the effect of the incorporation of nonmetals P on the electrocatalytic performance of PdRu binary catalysts, which will contribute to broadening the application of nonmetal P or even for other nonmetals for electrooxidation. Our efforts will dedicate to accelerating the commercialization of efficient and stable anode catalysts in fuel cells by means of doping transition metals or nonmetals into Pd.
Co-reporter:Hui Xu, Bo Yan, Ke Zhang, Jin Wang, Shumin Li, Caiqin Wang, Yukihide Shiraishi, Yukou Du, Ping Yang
Journal of Alloys and Compounds 2017 Volume 723(Volume 723) pp:
Publication Date(Web):5 November 2017
DOI:10.1016/j.jallcom.2017.06.230
•The core-shell PdAu convex nanospheres have been prepared via a green approach.•The PdAu catalysts with rough surface provide ideal catalytic active sites.•PdAu catalysts exhibit greatly enhanced catalytic activity and stability.The design of cost-efficient catalysts for the electrooxidation of liquid fuel is now highly desirable for the commercial application of direct fuel cells. In spired by this, we herein reported our tremendous efforts in the fabrication of core-shell PdAu convex nanospheres via a green method. Different from the previously reported PdAu core-shell nanostructures, the present PdAu convex nanospheres integrated the benefits of core/shell, many granular protuberances, alloy and electronic effect as well as high surface area. All of these favorable properties embody them to exhibit greatly enhanced electrocatalytic activity and long-term stability towards ethylene glycol oxidation as compared with commercial Pd/C. This work emphasizes the significance of shape-controlled of PdAu nanostructures over the electrocatalytic performances for the ethylene glycol oxidation.Download high-res image (351KB)Download full-size image
Co-reporter:Jin Wang, Beibei Yang, Shumin Li, Bo Yan, Hui Xu, Ke Zhang, Yuting Shi, Chunyang Zhai, Yukou Du
Journal of Colloid and Interface Science 2017 Volume 506(Volume 506) pp:
Publication Date(Web):15 November 2017
DOI:10.1016/j.jcis.2017.07.059
Herein, a sensitive photo-electrochemical sensor based on C3N4 and reduced graphene oxide nanosheets modified glassy carbon electrode (C3N4-RGO/GCE) has been fabricated for the detection of rutin under UV light illumination. In C3N4-RGO catalyst, RGO not only works as a template but also promotes electron transfer, meanwhile, C3N4 acts as a photocatalyst. Benefiting from the superior electron transfer capacity and efficient UV light effect of the C3N4-RGO catalyst, we get a photo-electrochemical sensor for the rutin detecting with a low detection limit of 1.78 × 10−9 mol L−1 and an excellent linear range of 5 × 10−9–1.4 × 10−4 mol L−1. Meanwhile, the achieved C3N4-RGO/GCE demonstrated nice selectivity, good reproducibility as well as reliable stability. Moreover, compared with the electrochemical determination, the C3N4-RGO electrode provides a new way for rutin detection by photo-electrochemical method with a promising UV light responsive result.Download high-res image (92KB)Download full-size image
Co-reporter:Hui Xu, Bo Yan, Ke Zhang, Jin Wang, Shumin Li, Caiqin Wang, Yukihide Shiraishi, Yukou Du, Ping Yang
Journal of Colloid and Interface Science 2017 Volume 505(Volume 505) pp:
Publication Date(Web):1 November 2017
DOI:10.1016/j.jcis.2017.05.067
The shape-controlled synthesis of binary Pd-based nanocrystals bounded with abundant surface active areas and tunable atomic ratio have been of great significance in the fabrication and modification of outstandingly excellent electrocatalysts. To embody the superiority of high surface area in enhancing electrocatalysis well, the superior electrocatalyst should be supposed to combine both the morphology advantages and the synergistic effect between metals. We herein report our significant advances in engineering the unique binary PdRu nanoflowers with highly exposed active sites and tunable compositions. Owing to the bifuntional effect and electronic effect between Pd and Ru, as well as the unique flower-like structure, such special PdRu nanoflower exhibit outstandingly excellent catalytic activity towards methanol electrooxidation with the mass activity of 1280 mA mg−1, 7.01 and 4.92-fold enhancement than that of pure Pd and commercial Pd/C. Our efforts in this work may open a new way for enhancing the catalytic activity by constructing the catalysts with desirable shape and maximizing the active surface areas.Download high-res image (169KB)Download full-size image
Co-reporter:Hui Xu, Ke Zhang, Bo Yan, Jin Wang, Caiqin Wang, Shumin Li, Zhulan Gu, Yukou Du, Ping Yang
Journal of Power Sources 2017 Volume 356(Volume 356) pp:
Publication Date(Web):15 July 2017
DOI:10.1016/j.jpowsour.2017.04.070
•The ultrasmall PdBi nanodots have been designed by a facile wet-chemical method.•The composition of PdBi nanodots can be easily controlled.•Mechanisms of formation have been explored.•The morphologies of PdBi nanocomposites is time-depended.•The obtained PdBi nanodots show superior electrocatalytic performances.Tuning the morphology and compositions of catalyst is an effective method for promoting electrocatalytic intrinsic activity. However, many newly-generated nanocrystals with better nanostructures often have a large size, which enforces them to display extremely limited surface area and ultimately lead to the limited electrocatalytic activity. To break this bottleneck, we herein report a facile and reproducible wet-chemical method to control the synthesis of a class of ultra-uniform and small PdBi nanodots endowed with both high surface areas and tunable compositions. The presented PdBi nanodots show the ultrasmall size (ca.2.5 nm) and great uniform dispersion property. These significant characteristics enable them to exhibit unprecedented electrocatalytic activities and durability toward formic acid oxidation. The mass activity and electrochemical surface active (ECSA) of prepared PdBi nanodots for the formic acid oxidation is 8.9/3.75 times higher than that of commercial Pd/C, respectively. We speculate that both of this facile synthetic approach and remarkable electrocatalytic performance of the obtained catalysts in this work illustrate that they can be applied as a promising catalyst for direct formic acid cells.Download high-res image (428KB)Download full-size image
Co-reporter:Shumin Li, Ke Zhang, Jin Wang, Bo Yan, Caiqin Wang, Zhiping Xiong, Hui Xu, Yukou Du
Sensors and Actuators B: Chemical 2017 Volume 252(Volume 252) pp:
Publication Date(Web):1 November 2017
DOI:10.1016/j.snb.2017.06.046
•UV light-assisted electrochemical determination of TA on ZnO-Pt/GCE.•3D flower like ZnO-Pt material was successfully synthesized by one-pot hydrolysis method.•A wide linear range of 0.04–72.34 μM with a low detection limit of 0.02 μM was obtained.Flower-like ZnO-Pt materials with three-dimensional architectures were synthesized by one-pot method, and a novel tannic acid (TA) analytical method based on flower-like ZnO-Pt modified glassy carbon electrode (ZnO-Pt/GCE) was also developed. Due to the introduction of metal Pt on ZnO, the as-prepared electrode exhibited good conductivity and gave rise to a significant increase in the photocurrent density under UV light illumination, confirming an enhanced charge transfer speed and a well combination between exited electron-hole pairs of ZnO. For the analysis of TA, differential pulse voltammetry (DPV) was applied to evaluate the photoelectrochemical performance on ZnO-Pt/GCE, and a wide linear range of 0.04–72.34 μM with a low detection limit of 0.02 μM (at S/N = 3) was obtained ultimately. The oxidation mechanism of tannic acid in different routes was also proposed and discussed. Moreover, the prepared electrode displayed high stability and selectivity toward the determination of tannic acid. These excellent results presented here make the ultraviolet assisted electrochemical determination a promising method in sensing.Download high-res image (103KB)Download full-size image
Co-reporter:Mingshan Zhu, Chunyang Zhai, Mingjuan Sun, Yufang Hu, Bo Yan, Yukou Du
Applied Catalysis B: Environmental 2017 Volume 203(Volume 203) pp:
Publication Date(Web):1 April 2017
DOI:10.1016/j.apcatb.2016.10.012
•Ultrasmall Pt clusters are well dispersed on the surface of the g-C3N4 nanosheets.•Pt/g-C3N4 as an efficient visible light driven photoelectrocatalyst for MOR.•Pt/g-C3N4 composite showed enhanced photoelectrocatalytic activity and stability.In this paper, ultrathin two dimensional (2D) g-C3N4 nanosheet worked as support for the deposition of ultrasmall Pt nanoclusters. The average size of Pt nanocluster is about 3.2 nm. Firstly, the as-prepared Pt/g-C3N4 modified electrode exhibited enhanced electrocatalytic ability in methanol oxidation reaction (MOR) compared to bare Pt nanoparticles. Moreover, when this electrode was upon visible light irradiation, higher performance of MOR was clearly observed compared to the traditional ambient electrocatalytic oxidation. This is owing to the synergistic effects of photocatalytic and electrocatalytic MOR together with the efficient interfacial charger transfer in Pt/g-C3N4. These results show that 2D ultrathin g-C3N4 nanosheets can be used as promising photoactived support in the fields of solar and chemical energy conversion and also provide more insights into developing novel visible light photo-responsive electrode in direct methanol fuel cell.The synergistic effects of electro- and photo- catalytic methanol oxidation reaction (MOR) of Pt/g-C3N4 contribute to the enhanced catalytic MOR performance.Download high-res image (196KB)Download full-size image
Co-reporter:Zhiping Xiong, Bo Yan, Ke Zhang, Caiqin Wang, ... Chunyang Zhai
Journal of the Taiwan Institute of Chemical Engineers 2017 Volume 75(Volume 75) pp:
Publication Date(Web):1 June 2017
DOI:10.1016/j.jtice.2017.03.008
•3D porous PdCu bimetallic alloys were synthetized through a facile method.•The network structure is important in strengthening electrocatalytic activity.•The PdCu nanocatalyst displays greatly enhanced electrocatalytic activities.•The introduction of Cu could improve the feasibility of the DEFCs in applications.In this study, three-dimensional (3D) porous PdCu bimetallic alloys were synthetized through a facile one-pot method by employing hydrazine hydrate, polyvinylpyrrolidone and sodium bromide as the reducing agent, surfactant and structure-directing agent, respectively. The network nanostructure offers large open pores and special morphology which plays an important role in strengthening ethanol electrocatalytic activity and durability. The as-prepared 3D network PdCu nanocatalyst displays greatly enhanced electrocatalytic activities towards ethanol oxidation in alkaline medium. Notably, the catalyst with Pd:Cu atomic ratio of 1:1 exhibits the highest electrocatalytic activity, its mass activity of ethanol oxidation reaches 3362.50 mA/mg, which is 7.20 times than that of commercial Pd/C catalyst. This study suggests that introduction of copper could possibly improve the feasibility of the direct ethanol fuel cells for real world applications by improving electrocatalytic activity and lowering production cost.Download high-res image (242KB)Download full-size image
Co-reporter:Shumin Li, Hui Xu, Bo Yan, Ke Zhang, ... Ping Yang
Journal of the Taiwan Institute of Chemical Engineers 2017 Volume 80(Volume 80) pp:
Publication Date(Web):1 November 2017
DOI:10.1016/j.jtice.2017.08.037
•A facile wet-chemical method has been developed to prepare these PtAu NCs.•The dendritic shell can help PtAu NCs expose abundant surface active sites.•The satellite-like PtAu NCs possess a great enhancement of catalytic activity.•The synergic and electronic effects also enhance their catalytic activities.Although substantial investigations on exploring highly-efficient Pt-based materials for serving as the desirable anode electrocatalysts for fuel cells have been carried out over decades, while the large-scale commercial application remains a formidable challenge. To this end, we herein combine the advantages of both compositions and morphology to successfully fabricate the fascinating satellite-like PtAu nanocrystals (PtAu NCs) with dendritic shell via a facile wet-chemical approach. A series of electrochemical measurements have revealed that the as-prepared binary PtAu NCs possessed the outstandingly high electrocatalytic activity toward ethylene glycol oxidation reaction (EGOR) with the mass activity of 4856.2 mA/mg, 4.47-fold enhancements than that of commercial Pt/C. Moreover, the satellite-like PtAu NCs can endure with less activity decay under durability test, demonstrating a novel class of Pt-based catalysts with excellent electrocatalytic performances for fuel cells and beyond. We do believe that both the synthetic strategy and the catalysts we developed in this work can well boost the commercial development of direct fuel cell.Download high-res image (205KB)Download full-size image
Co-reporter:Chunyang Zhai, Mingshan Zhu, Fenzhi Pang, Duan Bin, Cheng Lu, M. Cynthia Goh, Ping Yang, and Yukou Du
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 9) pp:5972
Publication Date(Web):February 18, 2016
DOI:10.1021/acsami.5b10234
A cadmium sulfide quantum dots sensitized Pt (Pt–CdS) composite was synthesized using a solvothermal method and characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV–vis diffuse reflectance spectroscopy. The catalytic properties of the as-prepared electrode for methanol oxidation were evaluated by cyclic voltammetry (CV), chronoamperometry, electrochemical impedance spectrum (EIS) and photocurrent responses. The as-prepared Pt–CdS electrode displayed a significant enhancement in the electrocatalytic activity and stability for methanol oxidation in the presence of visible light irradiation. The synergistic effect of both the electro- and photocatalytic reaction contributes to this enhanced catalytic performance. Our result suggests a new paradigm to construct photoelectrocatalysts with high performance and good stability for direct methanol fuel cells with the assistance of visible-light illumination.Keywords: cadmium sulfide; direct methanol fuel cells; photoelectrocatalysts; quantum dots; visible light;
Co-reporter:Jiatai Zhong, Duan Bin, Yue Feng, Ke Zhang, Jin Wang, Caiqin Wang, Jun Guo, Ping Yang and Yukou Du
Catalysis Science & Technology 2016 vol. 6(Issue 14) pp:5397-5404
Publication Date(Web):16 Mar 2016
DOI:10.1039/C6CY00140H
In this study, highly active Au-decorated Pd heterogeneous nanocubes with Pd/Au molar ratios ranging from 15:1 to 2:1 were successfully synthesized based on a successive reduction strategy. The structure, morphology and composition of the as-prepared catalysts were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM (HR-TEM), energy dispersive spectrometer (EDS) line scan and the elemental mapping. The results show that the lattice orientations of the Pd nanocubes match those of the Au layers. Structural analysis establishes that the surface of the Au-decorated Pd nanocrystal shows its {111} faces. The heterogeneous nanocubes were used for ethanol electro-oxidation reaction in alkaline media. The electrochemical results indicate that the addition of Au to Pd can significantly improve the performance including catalytic activity, CO tolerance and stability. These results clearly suggest that the relative amounts of Au and Pd on the surface of the nanocubes are crucial for the improvement of Pd catalysis, and Pd5Au1 is identified as the most efficient catalyst since it possesses superior catalytic activity and long-term stability.
Co-reporter:Ke Zhang, Caiqin Wang, Duan Bin, Jin Wang, Bo Yan, Yukihide Shiraishi and Yukou Du
Catalysis Science & Technology 2016 vol. 6(Issue 16) pp:6441-6447
Publication Date(Web):23 Jun 2016
DOI:10.1039/C6CY00789A
Highly active self-supported Pd/P nanoparticle networks were synthesized as anode electrocatalysts for direct methanol fuel cell reactions. Transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy were used to characterize the Pd/P catalysts. The results indicated that the composition does not affect the network structure. The electrocatalytic performances of elemental Pd, Pd4/P1, Pd2/P1 and Pd1/P1 nanoparticles were examined and the experimental results indicated that the Pd2/P1 catalyst showed optimal current densities in cyclic voltammetry and chronoamperometry measurements, which may be attributed to the electronic effect and its special nanostructure, having an interconnecting net structure, good electrical conductivity and high surface area. We postulate that the present method can be used as a promising and alternative approach for the design of anode electrocatalysts in direct methanol alkaline fuel cells.
Co-reporter:Jin Wang, Beibei Yang, Ke Zhang, Duan Bin, Yukihide Shiraishi, Ping Yang, Yukou Du
Journal of Colloid and Interface Science 2016 Volume 481() pp:229-235
Publication Date(Web):1 November 2016
DOI:10.1016/j.jcis.2016.07.061
A sensitive and novel electrochemical sensor with Au-Pd and reduced graphene oxide (RGO) nanocomposites modified glassy carbon electrode (Au-Pd-RGO/GCE) was successfully fabricated by one-step synthesis method for the detection of Sunset Yellow. The as-prepared composites were uniformly dispersed on the surface of electrode with an average diameter of approximately 3.44 nm, and the ultrafine nanoparticles effectively enhanced the electrochemical active surface area of GCE. The modified electrode had been characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and electrochemical tests. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) results showed high stability and outstanding electrocatalytic activity of Au-Pd-RGO/GCE for the detection of SY with low detection limits (1.5 nM, S/N = 3) and wide concentration ranges (0.686–331.686 μM). The Au-Pd-RGO/GCE was further applied to detect SY in real samples with good recovery. Herein, the fabricated Au-Pd-RGO/GCE showed excellent sensitivity, stability and repeatability for the detection of SY and will be a promising application in electrochemical sensor.
Co-reporter:Yue Feng, Duan Bin, Ke Zhang, Fangfang Ren, Jin Wang and Yukou Du
RSC Advances 2016 vol. 6(Issue 23) pp:19314-19321
Publication Date(Web):12 Feb 2016
DOI:10.1039/C5RA26994F
In this paper, a facile chemical reduction method was employed to synthesize bimetallic PdSn nanocatalysts, and the nitrogen-doped graphene (N-G) has been used as a conductive support material for PdSn catalysts. The structures, morphologies and composition of the catalysts were characterized by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. Electrochemical measurements such as cyclic voltammetry (CV), chronoamperometry (CA), electrochemical impedance spectrometry (EIS) were carried out to detect the electrochemical activity of the as-prepared catalysts toward ethanol electrooxidation in an alkaline medium. Among the PdSn/N-G catalysts with different molar ratios between Pd and Sn, the free-standing PdSn catalyst and commercial Pd/C catalyst, Pd3Sn1/N-G exhibited excellent catalytic activity and stability, indicating that nitrogen-doped graphene as a conductive support material and the moderate addition of Sn can enhance the electrochemical performance of Pd catalysts.
Co-reporter:Shumin Li, Beibei Yang, Jin Wang, Duan Bin, Caiqin Wang, Ke Zhang and Yukou Du
Analytical Methods 2016 vol. 8(Issue 27) pp:5435-5440
Publication Date(Web):06 Jun 2016
DOI:10.1039/C6AY01348A
In this article, a nonenzymatic electrochemical sensor based on chemically reduced graphene oxide (RGO) and a Pt nanoparticles (PtNPs) modified glassy carbon electrode has been fabricated and used to determine rutin. The nanocomposites of PtNPs/RGO were characterized by transmission electron microscopy and X-ray diffraction, and the electrochemical behaviors of rutin on PtNPs/RGO were demonstrated by cyclic voltammetry and differential pulse voltammetry. The as-fabricated electrochemical sensor for rutin exhibited a wide linear range from 0.057 to 102.59 μM with a detection limit of 0.02 μM (S/N = 3). Additionally, the as-prepared electrode displayed a good reproducibility, stability and anti-interference ability for the detection of rutin. Finally, the electrode was successfully applied for the determination of rutin in pharmaceutical tablets.
Co-reporter:Jiatai Zhong, Duan Bin, Fangfang Ren, Caiqin Wang, Chunyang Zhai, Ping Yang, Yukou Du
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2016 Volume 488() pp:1-6
Publication Date(Web):5 January 2016
DOI:10.1016/j.colsurfa.2015.09.069
•A facile electrochemical approach for synthesizing the Pd nano-leaves.•The Pd nano-leaves/RGO catalysts display stronger poisoning-tolerance.•The Pd nano-leaves/RGO catalysts exhibit better catalytic activity and stability.This paper reports a facile electrochemical approach for synthesizing the Pd nano-leaves supported on reduced graphene oxide (RGO) modified glassy carbon electrode (GCE). The as-synthesized Pd nano-leaves/RGO/GCE catalyst has been characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). SEM images show that a large number of Pd nano-leaves are uniformly deposited on the surface of RGO. Electrochemical measurements indicate that the as-synthesized Pd nano-leaves/RGO/GCE catalyst displays higher electrocatalytic activity and stronger poisoning-tolerance towards formic acid oxidation reaction as compared to the Pd nano-leaves/GCE and commercial Pd/C/GCE catalysts. This work explores a novel approach for the formation of nano-leaves structure, which can provide its important application in fuel cells.The as-prepared Pd nano-leaves/RGO/GCE shows the highest electrocatalytic performance toward formic acid oxidation.
Co-reporter:Zhiping Xiong, Ke Zhang, Caiqin Wang, Yukihide Shiraishi, Jun Guo, Yukou Du
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2016 Volume 502() pp:13-18
Publication Date(Web):5 August 2016
DOI:10.1016/j.colsurfa.2016.05.002
•PdPbPt interconnected network type nanoparticles have been synthesized by a facile route.•The ethanol electrocatalytic activity of PdPb nanocomposites was highly enhanced by a small amount platinum modification.•The anodic peak current densityon Pd1Pb1Pt0.027 electrode can reach as high as 6936 mA mg-1.In this work, PdPbPt interconnected network type nanoparticles have been fabricated by a facile route, and the as-prepared PdPbPt composites were characterized by transmission electron microscopy (TEM), high-resolution TEM (HRTEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. It is found that PVP plays an important role in enhancing the dispersion and stability of the catalyst. Moreover, the resultant network Pd1Pb1Pt0.027 nanoparticles reveal superior electrocatalytic activity and stability for the ethanol electro-oxidation reaction for comparison with other as-synthesized catalysts, which the anodic peak current density on Pd1Pb1Pt0.027 electrode can reach as high as 6936 mA mg−1, suggesting that Pd1Pb1Pt0.027 composite can be a promising catalyst for fuel cells.
Co-reporter:Caiqin Wang, Huiwen Wang, Chunyang Zhai, Fangfang Ren, Mingshan Zhu, Ping Yang and Yukou Du
Journal of Materials Chemistry A 2015 vol. 3(Issue 8) pp:4389-4398
Publication Date(Web):09 Jan 2015
DOI:10.1039/C4TA05193A
A three-dimensional Au nanoparticle/reduced graphene oxide (RGO)/carbon fiber (CF) hybrid electrode (denoted as Au0.5/RGO/Au0.5/RGO/CF) was fabricated via a layer-by-layer method. The as-formed composite was characterized by Raman spectrometry, X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectrometry. Two RGO sheets and two Au nanoparticle sheets were assembled in alternate layers on the CFs. The catalytic performance of the as-prepared electrode was evaluated via cyclic voltammetry and chronopotentiometry. The as-synthesized three-dimensional Au0.5/RGO/Au0.5/RGO/CF electrode showed highly efficient electrocatalytic activity toward ethanol oxidation in alkaline medium and the Au nanoparticles were not affected by the graphene layers. The synergistic interaction between the RGO sheets and Au nanoparticles enhanced the catalytic activity of the electrode. The excellent electronic conductivity of the RGO sheets benefited electron transfer and the removal of the intermediate species by oxidation during the ethanol electrooxidation reaction, which improved the catalytic activity. As a result of the effects of these multiple factors, the Au0.5/RGO/Au0.5/RGO/CF electrode displayed a good catalytic performance.
Co-reporter:Duan Bin, Beibei Yang, Fangfang Ren, Ke Zhang, Ping Yang and Yukou Du
Journal of Materials Chemistry A 2015 vol. 3(Issue 26) pp:14001-14006
Publication Date(Web):26 May 2015
DOI:10.1039/C5TA02829A
This paper reports a simple method, in which Ni nanoparticles act as seeds for the formation of reduced graphene oxide (RGO) supported PdNi nanowire networks. The as-prepared catalysts were characterized by transmission electron microscopy (TEM), high-resolution TEM (HRTEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Electrochemical measurements proved that the PdNi-NNs/RGO catalyst has superior electrocatalytic activity towards the formic acid oxidation reaction with much larger electrochemically active surface area and mass activity as well as higher long term-stability in comparison with the Pd/RGO and commercial Pd/C catalysts. The optimized ratio of Pd and Ni is 1:1, tuned by simply adjusting the feed ratio of the precursors as well. It is proposed that the improvement of the catalytic performance is attributed to the special nanostructure and the synergistic effect between Pd and Ni. These findings highlight the facile synthesis of the PdNi nanowire networks on RGO sheets and their promising application as electrocatalysts for fuel cells.
Co-reporter:Beibei Yang, Jin Wang, Duan Bin, Mingshan Zhu, Ping Yang and Yukou Du
Journal of Materials Chemistry A 2015 vol. 3(Issue 37) pp:7440-7448
Publication Date(Web):21 Aug 2015
DOI:10.1039/C5TB01031D
An electrochemical sensor using a novel three dimensional (3D) ternary Pt nanodendrite/reduced graphene oxide/MnO2 nanoflower (Pt/RGO/MnO2) modified glassy carbon electrode was proposed for the selective and sensitive determination of dopamine (DA) in the presence of ascorbic acid (AA) and uric acid (UA). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to evaluate electrochemical behaviors of DA on the as-prepared electrode. The oxidation peak current of DA is linearly proportional to its concentration in the range from 1.5–215.56 μM, with a detection limit of 0.1 μM (at S/N = 3). Compared to bare RGO, Pt nanodendrite/RGO and MnO2 nanoflower modified electrodes, the 3D hierarchical ternary Pt/RGO/MnO2 composites displayed the highest electrocatalytic activity for the selective detection of DA. Moreover, the 3D Pt/RGO/MnO2 modified electrode can be reused with no obvious deterioration in the electrocatalytic performance. This work paves the way for developing a novel 3D nanostructure and offers new opportunities for improving the performance of electrochemical sensors with excellent sensitivity, repeatability and anti-interference.
Co-reporter:Ke Zhang, Duan Bin, Beibei Yang, Caiqin Wang, Fangfang Ren and Yukou Du
Nanoscale 2015 vol. 7(Issue 29) pp:12445-12451
Publication Date(Web):17 Jun 2015
DOI:10.1039/C5NR02713F
Due to the specific physical and chemical properties of a highly branched noble metal, the controllable synthesis has attracted much attention. This article reports the synthesis of Pd/Ru nanodendrites by a facile method using an oil bath in the presence of polyvinyl pyrrolidone, potassium bromide and ascorbic acid. The morphology, structure, and composition of the as-prepared catalysts were characterized by means of X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. In the electrochemical measurement, the as-prepared Pd7/Ru1 bimetallic nanodendrites provide a large electrochemically active surface area and exhibit high peak current density in the forward scan toward ethanol electrooxidation, which is nearly four times higher than those of a pure Pd catalyst. The as-prepared Pd7/Ru1 catalysts also exhibit significantly enhanced cycling stability toward ethanol oxidation in alkaline medium, which are mainly ascribed to the synergetic effect between Pd and Ru. This indicates that the Pd7/Ru1 catalysts should have great potential applications in direct ethanol fuel cells.
Co-reporter:Fangfang Ren, Chunyang Zhai, Mingshan Zhu, Caiqin Wang, Huiwen Wang, Duan Bin, Jun Guo, Ping Yang, Yukou Du
Electrochimica Acta 2015 Volume 153() pp:175-183
Publication Date(Web):20 January 2015
DOI:10.1016/j.electacta.2014.11.184
•GO could be reduced and modified simultaneously by PDA without using reducing agents.•PDA plays an important role in enhancing the dispersion and stability of the catalyst.•The bimetallic PtAu/PDA-RGO catalysts exhibits higher catalytic activity than the monometallic Pt/PDA-RGO toward MOR.•The PtAu(3:1)/PDA-RGO catalyst also shows better catalytic activity for MOR than PtAu(3:1)/RGO and PtAu(3:1)/C catalysts.In this paper, a facile strategy for the synthesis of PtAu nanoparticles (NPs) with different Pt/Au ratios supported on polydopamine reduced and modified graphene oxide (PtAu/PDA-RGO) is reported. The as-prepared PtAu/PDA-RGO composites were extensively analyzed by transmission electron microscopy (TEM), high-resolution TEM (HRTEM), Raman spectroscopy, energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. It is found that PDA plays an important role in enhancing the dispersion and stability of the catalyst. Moreover, the bimetallic PtAu/PDA-RGO catalysts exhibits higher catalytic activity than the monometallic Pt/PDA-RGO toward methanol oxidation reaction (MOR), with the best performance found for the Pt/Au molar ratio of 3/1. The PtAu(3:1)/PDA-RGO catalyst also shows better catalytic activity for MOR than PtAu(3:1)/RGO and PtAu(3:1)/C catalysts, suggesting that PDA-RGO can be a promising catalyst support for fuel cells. These findings also indicate that the molar ratios of Pt/Au and the catalyst support are the two critical factors to affect the overall performance of the catalyst.A facile and clean method for the synthesis of PtAu nanoparticles with different Pt/Au ratios supported on polydopamine reduced and modified graphene oxide (PtAu/PDA-RGO) is reported, which exhibit higher electro-catalytic performance and stability towards methanol oxidation in alkaline medium.
Co-reporter:Jin Wang, Beibei Yang, Huiwen Wang, Ping Yang, Yukou Du
Analytica Chimica Acta 2015 Volume 893() pp:41-48
Publication Date(Web):17 September 2015
DOI:10.1016/j.aca.2015.08.042
•An Au/RGO composite was fabricated by electrochemical deposition method.•The oxidation current of SY on the composition is up to 10 μA.•The detection range of SY is 0.002–109.14 μM with a detection limit of 2 nM.An electrochemical sensor was prepared using Au nanoparticles and reduced graphene successfully decorated on the glassy carbon electrode (Au/RGO/GCE) through an electrochemical method which was applied to detect Sunset Yellow (SY). The as-prepared electrode was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and electrochemical measurements. The results of cyclic voltammetry (CV) proved that Au/RGO/GCE had the highest catalytic activity for the oxidation of SY as compared with GCE, Au/GCE, and RGO/GCE. Differential pulse voltammetry (DPV) showed that the linear calibration curves for SY on Au/RGO/GCE in the range of 0.002 μM–109.14 μM, and the detection limit was estimated to be 2 nM (S/N = 3). These results suggested that the obtained Au/RGO/GCE was applied to detect SY with high sensitivity, low detection limit and good stability, which provided a promising future for the development of portable sensor in food additives.
Co-reporter:Huiwen Wang, Caiqin Wang, Beibei Yang, Chunyang Zhai, Duan Bin, Ke Zhang, Ping Yang and Yukou Du
Analyst 2015 vol. 140(Issue 4) pp:1291-1297
Publication Date(Web):17 Dec 2014
DOI:10.1039/C4AN01924E
We describe a simple electrochemical preparation method of a novel three dimensional (3D) graphene material, porous flower-like reduced graphene oxide (f-RGO) nanosheets, which was explored as the support for Cu particles on a glassy carbon electrode (Cu/f-RGO/GCE) for detecting nitrite. In morphology studies, scanning electron microscopy (SEM) demonstrates the 3D porous structure of f-RGO enlarges the surface area of the electrode and promotes more Cu particles depositing on the surface of f-RGO with homogeneous dispersion. In cyclic voltammetry (CV), a well-defined voltammetric peak along with the remarkable reduction current indicates excellent electrocatalytic activity of the Cu/f-RGO/GCE for NaNO2 reduction compared with other corresponding electrodes. The effects of pH value and detection potential on the current responses of Cu/f-RGO/GCE towards nitrite were optimized to obtain the maximal sensitivity. In the optimal experimental conditions, Cu/f-RGO/GCE displays the wide detection range from 0.15 μM to 10500 μM and the low limit of detection of 0.06 μM (S/N = 3) with fast response time 2 s for detecting NaNO2 through an amperometric method. Furthermore, the presence of K+, Na+, Cl−, NH4+, NO3−, SO42− and ascorbic acid show a negligible effect on the current response of nitrite determination suggesting Cu/f-RGO/GCE have the high selectivity for detecting nitrite even in the presence of high concentration of interferents. Moreover, the real sample determination experiment indicated practical feasibility of the obtained sensor. The prepared sensor for determination of NaNO2 exhibited wide liner range, low detection limit, good reproducibility, nice stability and remarkable anti-interference ability. In this paper, not only did the Cu/f-RGO/GCE show high performance for determination of nitrite, but also it was simple to prepare, user-friendly and cost-effective.
Co-reporter:Dr. Fangfang Ren;Ke Zhang;Duan Bin;Beibei Yang;Huiwen Wang; Ping Yang; Zhenghao Fei; Yukou Du
ChemCatChem 2015 Volume 7( Issue 20) pp:3299-3306
Publication Date(Web):
DOI:10.1002/cctc.201500472
Abstract
A novel composite catalyst of Pd nanoparticles supported on 1,6-hexanediamine-functionalized reduced graphene oxide (HD-RGO) has been successfully synthesized by a facile chemical method. The as-synthesized composite catalyst has been extensively characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and electrochemical tests. TEM images show that Pd nanoparticles with smaller diameters of (3.30±1.20) nm are more evenly dispersed on the HD-RGO surface than those supported on RGO. Electrochemical tests reveal that the as-prepared Pd/HD-RGO catalyst displays higher electrocatalytic activity, better tolerance, and better electrochemical stability toward ethanol oxidation in alkaline media in comparison with Pd/RGO and commercial Pd/C catalysts. The Pd/HD-RGO catalyst may be a promising potential catalyst in direct ethanol fuel cells.
Co-reporter:Duan Bin;Dr. Fangfang Ren;Ying Wang;Dr. Chunyang Zhai;Dr. Caiqin Wang; Jun Guo; Ping Yang; Yukou Du
Chemistry – An Asian Journal 2015 Volume 10( Issue 3) pp:667-673
Publication Date(Web):
DOI:10.1002/asia.201403142
Abstract
Poly(diallyldimethylammonium chloride) (PDDA) has been employed as a modifying material for the development of new functional materials; then, the functionalized graphene was employed as a support for Pd nanoparticles through a facile method. The structures and morphologies of the as-synthesized Pd/PDDA–graphene composites were extensively characterized by Raman spectroscopy, XRD, XPS, and TEM. Morphological observation showed that Pd NPs with average diameters of 4.4 nm were evenly deposited over the functionalized graphene sheets. Moreover, the electrochemical experiments indicated that the Pd/PDDA–graphene catalyst showed improved electrocatalytic activity toward alcohol-oxidation reactions compared to the Pd/graphene and commercial Pd/C systems, as well as previously reported Pd-based catalysts. This study demonstrates the great potential of PDDA-functionalized graphene as a support for the development of metal–graphene nanocomposites for important applications in fuel cells.
Co-reporter:Ke Zhang;Fangfang Ren;Huiwen Wang;Caiqing Wang;Dr. Mingshan Zhu; Yukou Du
ChemPlusChem 2015 Volume 80( Issue 3) pp:529-535
Publication Date(Web):
DOI:10.1002/cplu.201402231
Abstract
A facile, eco-friendly method for the synthesis of gold/platinum catalysts through electrodeposition of platinum nanoparticles, followed by the deposition of solutions of HAuCl4 onto the surface of pre-prepared platinum for a galvanic replacement reaction, is reported. Different molar ratios of bimetallic structures of platinum and gold could be easily achieved and characterized by energy-dispersive X-ray spectroscopy, SEM, and XRD. Electrochemical measurements reveal that the electrocatalytic activities of these series of gold/platinum catalysts towards formic acid oxidation reaction are superior to that of pure platinum. In addition, the formic acid oxidation route is related to the molar ratio of gold to platinum, which can be ascribed to the influence of gold. The gold/platinum catalyst with a platinum to gold atomic ratio of 2.51:1 exhibits maximum activity. Moreover, this optimized molar ratio shows a highly stable electrocatalytic activity for CO antipoisoning effects. These experimental results suggest that the prepared gold/platinum catalysts have great potential for applications in fuel cells.
Co-reporter:Ke Zhang, Huiwen Wang, Caiqin Wang, Beibei Yang, Fangfang Ren, Ping Yang, Yukou Du
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2015 Volume 467() pp:211-215
Publication Date(Web):20 February 2015
DOI:10.1016/j.colsurfa.2014.11.059
•The PtCuAu/RGO was fabricated by electrochemical method.•PtCuAu nanoparticles were uniformly electrodeposited on the RGO surface.•The PtCuAu/RGO showed high catalytic activity for formic acid electrooxidation.A facile electrochemical approach to synthesize reduced graphene oxide (RGO) modified glassy carbon (GC) electrode as an excellent support for anchoring PtCuAu nanoparticles is reported. The as-prepared PtCuAu/RGO catalyst has been characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and electrochemical methods. It is found that the PtCuAu nanoparticles formed alloy structures and are evenly distributed on the RGO substrate. Compared with Pt/RGO, PtCu/RGO, PtAu/RGO and CuAu/RGO electrodes, the PtCuAu/RGO catalyst exhibits distinctly enhanced current density and nice stability toward formic acid electrooxidation. The experimental results indicate that the prepared PtCuAu/RGO catalyst has enormous potential applications in direct formic acid fuel cells (DFAFC).
Co-reporter:Beibei Yang, Duan Bin, Huiwen Wang, Mingshan Zhu, Ping Yang, Yukou Du
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2015 Volume 481() pp:43-50
Publication Date(Web):20 September 2015
DOI:10.1016/j.colsurfa.2015.04.027
•Pt nanoparticles-reduced graphene oxide composites are fabricated by one-pot hydrothermal method.•The composite has an enhanced electrochemical activity toward the oxidation of nitrite.•Amperometric response presents an especially high sensitivity of 496.4 μA mM−1.•The prepared electrode is used as a sensor for the determination of nitrite in beverage samples.A promising electrochemical sensor, Pt nanoparticles decorated on the surface of reduced graphene oxide (RGO) sheets were facilely synthesized by a one-pot hydrothermal method. The morphology and composition of as-prepared Pt–RGO composites have been characterized by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and X-ray diffraction (XRD). It is found that Pt nanoparticles with ca. 4.81 ± 1.54 nm in diameter were evenly distributed on the surface of RGO sheets. The cyclic voltammetry shows that Pt–RGO nanocomposite has a higher electron transfer rate and remarkable increase electrochemical activity toward the oxidation of nitrite. The amperometry reveals that the Pt–RGO modified electrode exists a good linear relationship between peak current and concentration of nitrite with a low detection limit of 0.1 μM and high sensitivity of 496.4 μA mM−1. Moreover, the as-synthesized Pt–RGO electrode display a fast amperometric response within 4 s. Compared to the bare Pt nanoparticles or the RGO modified glassy carbon (GC) electrode, the as-synthesized Pt–RGO nanocomposite shows a well reproducibility, stability and anti-interference electrocatalytic performance toward nitrite sensing.
Co-reporter:Chunyang Zhai, Mingshan Zhu, Duan Bin, Huiwen Wang, Yukou Du, Chuanyi Wang, and Ping Yang
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 20) pp:17753
Publication Date(Web):October 2, 2014
DOI:10.1021/am504263e
In this work, Pt nanoflowers deposited on highly ordered TiO2 nanotube arrays (TNTs) by modification of reduced graphene oxide (RGO) nanostructures have been synthesized. The ternary complex (Pt-TNTs/RGO) displays efficient electrocatalytic performance toward methanol oxidation in alkaline medium. The electrochemical impedance spectroscopy (EIS) and responsive photocurrent results indicate that the presence of graphene could effectively promote charge separation during electrocatalytic process. Interestingly, with assistance of visible light illumination, the electrocatalytic activity and stability of the ternary complex electrode toward methanol oxidation are distinctly improved. Both electro- and photo-catalytic processes for methanol oxidation contribute to the enhanced catalytic performance and stability. Moreover, the ternary electrode also displays efficient photoelectrocatalytic degradation of methylene blue (MB) under visible light illumination. The present work sheds light on developing highly efficient and long-term stability catalysts for methanol oxidation with assistance of visible-light illumination.Keywords: electrocatalytic oxidation; graphene; Pt nanoflowers; TiO2 nanotubes; visible-light
Co-reporter:Fangfang Ren, Huiwen Wang, Chunyang Zhai, Mingshan Zhu, Ruirui Yue, Yukou Du, Ping Yang, Jingkun Xu, and Wensheng Lu
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 5) pp:3607
Publication Date(Web):January 23, 2014
DOI:10.1021/am405846h
In this article, a clean method for the synthesis of PtPd/reduced graphene oxide (RGO) catalysts with different Pt/Pd ratios is reported in which no additional components such as external energy (e.g., high temperature or high pressure), surfactants, or stabilizing agents are required. The obtained catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), induced coupled plasma atomic emission spectroscopy (ICP–AES), and electrochemical measurements. The HRTEM measurements showed that all of the metallic nanoparticles (NPs) exhibited well-defined crystalline structures. The composition of these Pt–Pd/RGO catalysts can be easily controlled by adjusting the molar ratio of the Pt and Pd precursors. Both cyclic voltammetry (CV) and chronoamperometry (CA) results demonstrate that bimetallic PtPd catalysts have superior catalytic activity for the ethanol oxidation reaction compared to the monometallic Pt or Pd catalyst, with the best performance found with the PtPd (1:3)/RGO catalyst. The present study may open a new approach for the synthesis of PtPd alloy catalysts, which is expected to have promising applications in fuel cells.Keywords: alkaline; electrocatalytic activity; ethanol oxidation; fuel cell; PtPd nanoparticles; reduced graphene oxide;
Co-reporter:Chunyang Zhai, Mingshan Zhu, Yongtao Lu, Fangfang Ren, Caiqin Wang, Yukou Du and Ping Yang
Physical Chemistry Chemical Physics 2014 vol. 16(Issue 28) pp:14800-14807
Publication Date(Web):01 May 2014
DOI:10.1039/C4CP01401D
In this paper, reduced graphene oxide modified highly ordered TiO2 nanotube arrays (RGO–TNTs) have been fabricated and used for photoelectrocatalytic (PEC) degradation of organic pollutants under visible light irradiation. Firstly, the RGO–TNT electrode was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman, FT-IR, X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance spectroscopy. The responsive photocurrent and electrochemical impedance spectroscopy (EIS) results indicated that our present RGO–TNTs displayed superior photoresponsive and electron transfer performances compared with bare TNTs. Moreover, by comparison with bare TNT electrode, the RGO–TNT arrays showed stable and evidently improved PEC activity for degradation of methyl orange (MO) under visible light illumination. This might be attributed to the introduction of RGO, which extended the absorption edge and promoted electron–hole separation in the PEC process. Furthermore, owing to the synergetic effect of photocatalysis and electrocatalysis in the PEC process, the efficiency of PEC process (3.0 × 10−3 min−1) is ca. 7.9 and 2.5 times faster than that of the electrochemical process (3.8 × 10−4 min−1) and photocatalytic process (1.2 × 10−3 min−1), respectively. Our investigation likely provides new opportunities for developing stable and efficient one-dimensional graphene modified TNT-based catalysts for PEC degradation of organic pollutants under visible light illumination.
Co-reporter:Ruirui Yue, Fangfang Ren, Caiqin Wang, Jingkun Xu and Yukou Du
RSC Advances 2014 vol. 4(Issue 1) pp:500-504
Publication Date(Web):11 Nov 2013
DOI:10.1039/C3RA45562A
Graphene-nanosheet clusters with flower-like hierarchical structure (f-GNSCs) were facilely fabricated by an electrochemical method with the assistance of copper particles. Such unique 3D macroporous graphene (GE) structure possesses remarkable electrochemical capacitance (up to 347.1 F g−1), good rate capability and cycle stability.
Co-reporter:Qiang Zhang, Fengxing Jiang, Ruirui Yue and Yukou Du
RSC Advances 2014 vol. 4(Issue 24) pp:12105-12108
Publication Date(Web):20 Feb 2014
DOI:10.1039/C4RA00106K
Graphene with a well-defined flower-like structure, for the first time, has been fabricated by a facile electrochemical method, which is explored as the support for the Pt catalyst for methanol electro-oxidation. The results demonstrate that the Pt-modified flower-like graphene (Pt/f-RGO) catalyst has remarkable electrocatalytic activity (1198.6 mA mg−1 Pt).
Co-reporter:Fangfang Ren, Huiwen Wang, Mingshan Zhu, Wensheng Lu, Ping Yang and Yukou Du
RSC Advances 2014 vol. 4(Issue 46) pp:24156-24162
Publication Date(Web):23 May 2014
DOI:10.1039/C4RA02499K
In this work, a facile electrochemical method for the fabrication of a novel poly(o-methoxyaniline)-modified graphene hybrid material (POMA/GE) as an efficient catalyst support for PtNi nanoparticles (NPs) on a glassy carbon (GC) electrode is reported. The morphology and structure of the PtNi/POMA/GE have been analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX) and Raman spectroscopy. Electrochemical techniques such as cyclic voltammetry, chronoamperometry, chronopotentiometry and impedance spectroscopy have been employed to investigate the electrocatalytic activities of the catalyst for methanol oxidation. It is found that PtNi/POMA/GE/GC catalyst exhibits excellent electrocatalytic activity toward methanol oxidation as compared to PtNi/GE/GC, PtNi/POMA/GC and PtNi/GC catalysts, showing that POMA/GE is a promising catalyst support material for use in methanol fuel cells. The enhanced performance is proposed to originate from the good dispersion of PtNi NPs on the POMA/GE film with a quasi-three-dimensional porous structure leading to the increase of the electrochemically active surface area (ECSA) as well as the synergic effect among the POMA, GE, and PtNi NPs.
Co-reporter:Huiwen Wang, Fangfang Ren, Caiqin Wang, Beibei Yang, Duan Bin, Ke Zhang and Yukou Du
RSC Advances 2014 vol. 4(Issue 51) pp:26895-26901
Publication Date(Web):09 Jun 2014
DOI:10.1039/C4RA03148B
A facile and cost-effective approach has been developed towards electrochemical fabrication of a reduced graphene oxide (RGO) modified glassy carbon electrode (RGO/GCE). Scanning electron microscopy (SEM) images show that RGO is covered completely on the surface of glassy carbon electrodes. The RGO/GCE is used to detect dopamine (DA), uric acid (UA) and ascorbic acid (AA) simultaneously via cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. Compared with bare GCE, RGO/GCE exhibits much high electrocatalytic activities toward the oxidation of DA, UA and AA, and three well-defined fully resolved anodic peaks were found in the CV curve at RGO/GCE. The GCEs modified with different amounts of RGO have an obvious influence on the determination of DA, UA and AA. By changing the concentrations of DA, UA and AA in the three substances coexisting system, the linear response ranges for the determination of DA, UA and AA were 0.1–400 μM, 2–600 μM, and 0.7–100 μM with the limit of detection (LOD) (S/N = 3) were estimated to be 0.1 μM, 1 μM and 0.7 μM, respectively. Moreover, it is found that RGO/GCE displays high reproducibility and selectivity for the determination of DA, UA and AA.
Co-reporter:Caiqin Wang, Fangfang Ren, Chunyang Zhai, Ke Zhang, Beibei Yang, Duan Bin, Huiwen Wang, Ping Yang and Yukou Du
RSC Advances 2014 vol. 4(Issue 101) pp:57600-57607
Publication Date(Web):28 Oct 2014
DOI:10.1039/C4RA08949A
A series of Au–Cu–Pt ternary catalysts were fabricated on glassy carbon electrode (GCE) by a two-step method. Au–Cu nanoparticles were formed by initial electrodeposition of Au–Cu layers onto GCE and then followed by the partial replacement of Cu by Pt. The morphology and composition of Au–Cu–Pt catalysts were characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), EDX element mapping and X-ray photoelectron spectroscopy (XPS). It was found that the alloying micro-structures existed in the catalysts among Au, Cu and/or the partially replaced Pt. Moreover, electrochemical measurements revealed that despite low loading of Pt, the Au–Cu–Pt/GCE-10 catalyst presented superior electrocatalytic activity and stability to that of the other comparative electrodes toward methanol electrooxidation (MEO). It indicated that this two-step method can efficiently decrease the amount of Pt loading in the catalyst. These findings also suggested that the prepared Au–Cu–Pt catalyst has a great potential for use in the direct methanol fuel cell (DMFC).
Co-reporter:Caiqin Wang, Ruirui Yue, Huiwen Wang, Cuie Zou, Jiao Du, Fengxing Jiang, Yukou Du, Ping Yang, Chuanyi Wang
International Journal of Hydrogen Energy 2014 Volume 39(Issue 11) pp:5764-5771
Publication Date(Web):4 April 2014
DOI:10.1016/j.ijhydene.2014.01.192
•A three-dimensional (3D) RGO/PtAg/TiO2/CF electrode has been fabricated.•The PtAg bimetal composites are with a dendritic profile and a core–shell structure.•The RGO sheets act as a shielding layer coating on the surface of PtAg/TiO2/CF.•RGO/PtAg/TiO2/CF presents enhanced photo-electrooxidation performances for methanol.•TiO2, dendritic PtAg and RGO have integrated effects on the catalytic performances.A facile, multi-step method has been developed for the fabrication of three-dimensional (3D) RGO/Ag@Pt/TiO2/CF electrode, which is composed of dendritic Ag@Pt core–shell catalyst, reduced graphene oxide (RGO), TiO2 spheres, and carbon fiber (CF). The Ag@Pt dendrite and TiO2 spheres supported on CF are coated with the gauze-like RGO sheets. After complexing with RGO, the light absorption of RGO/Ag@Pt/TiO2/CF is extended to longer wavelength region in comparison with pure TiO2. Moreover, the photo-electrocatalytic performance of RGO/Ag@Pt/TiO2/CF electrode toward methanol oxidation is thoroughly studied by evaluating these factors including electrochemical activity surface area, peak current density, the poisoning tolerance against COads and long-term stability. The results demonstrate that photo-electrocatalytic performance of RGO/Ag@Pt/TiO2/TiO2/CF electrode is enhanced under the UV irradiation in comparison with widely used Pt/C-JM electrode and its counterpart, Ag@Pt/TiO2/CF electrode.
Co-reporter:Huiwen Wang, Fangfang Ren, Ruirui Yue, Caiqin Wang, Chunyang Zhai, Yukou Du
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2014 Volume 448() pp:181-185
Publication Date(Web):20 April 2014
DOI:10.1016/j.colsurfa.2014.02.028
•The f-RGO/GCE was fabricated by electrochemical method.•The flower-like graphene framework has a well-defined distributed on GCE.•The f-RGO/GCE shows good responsiveness and high selectivity for DA detection.Well-defined flower-like graphene-nanosheet clusters (f-RGO) have been facilely and cost-effectively fabricated by electrochemical method on the surface of a glassy carbon electrode (GCE). The obtained f-RGO was directly used for the detection of dopamine (DA) via cyclic voltammetry (CV) and differential pulse voltammetry (DPV) technique. The structure of f-RGO was confirmed by scanning electron microscopy (SEM). It is observed that the f-RGO exhibits typical flower-like interconnected macroporous architecture, which contributes much to the high performance toward DA detection as compared with that of the layer-stacking RGO. For f-RGO, DPV measurement gives a wide liner range from 5 μM to 70 μM and 100 μM to 600 μM, respectively, and a good detection limit of 3 μM (S/N = 3) for the determination of DA. Moreover, the determination of DA with f-RGO is highly selective and reproducible, with a relative standard deviation of 3.0%.
Co-reporter:Beibei Yang, Huiwen Wang, Jiao Du, Yunzhi Fu, Ping Yang, Yukou Du
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2014 Volume 456() pp:146-152
Publication Date(Web):20 August 2014
DOI:10.1016/j.colsurfa.2014.05.029
•The ErGO/CFE was fabricated by a simple electrodeposition method.•The ErGO/CFE shows high electron transfer kinetics in CV response.•The ErGO/CFE shows high sensitivity and selectivity for simultaneous determination of AA, DA and UA.The electrochemically reduced graphene oxide (ErGO) modified carbon fiber electrode (CFE) was fabricated by a simple electrodeposition method. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) had been used to investigate the electrochemical behavior of ErGO/CFE toward ascorbic acid (AA), dopamine (DA) and uric acid (UA). Compared to the bare CFE, the ErGO/CFE showed higher catalytic activity toward electrochemical oxidation of AA, DA and UA. In the CV curves, three well and distinct peaks with large peak potential separation of 116 mV, 167 mV and 283 mV between AA–DA, DA–UA and AA–UA were observed. In the DPV curves, the corresponding peak potential separations were 198 mV, 163 mV and 361 mV between AA–DA, DA–UA and AA–UA also observed. DPV was used as the analytical technique to acquire the linear calibration curves for AA, DA and UA with the concentration ranges of 8–2016.45 μM, 1.5–224.82 μM, 6–899.3 μM, respectively, in the individual detection of each component. The detection limits were 4.5 μM, 0.77 μM and 2.23 μM for AA, DA and UA indicating that the ErGO/CFE can be achieved with high sensitivity and selectivity for simultaneous determination of these three biomolecules.
Co-reporter:Jiao Du, Ruirui Yue, Fangfang Ren, Zhangquan Yao, Fengxing Jiang, Ping Yang, Yukou Du
Biosensors and Bioelectronics 2014 Volume 53() pp:220-224
Publication Date(Web):15 March 2014
DOI:10.1016/j.bios.2013.09.064
Co-reporter:Fangfang Ren, Caiqin Wang, Chunyang Zhai, Fengxing Jiang, Ruirui Yue, Yukou Du, Ping Yang and Jingkun Xu
Journal of Materials Chemistry A 2013 vol. 1(Issue 24) pp:7255-7261
Publication Date(Web):16 Apr 2013
DOI:10.1039/C3TA11291H
In this paper, we report a facile, eco-friendly, one-pot method for the synthesis of a reduced graphene oxide (RGO) supported PtAuRu alloy nanoparticle catalyst (PtAuRu/RGO) by simultaneous reduction of H2PtCl6, HAuCl4, RuCl3 and graphene oxide (GO) using ethanol as the reduction agent. The as-formed PtAuRu/RGO catalyst has been characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and induced coupled plasma-atomic emission spectroscopy (ICP-AES). It is found that the PtAuRu nanoparticles formed alloy structures about 3.09 ± 0.73 nm in diameter and are evenly distributed on the RGO surface. The reduction degree of GO together with metal precursors is higher than that of only GO. Moreover, electrochemical measurements reveal that the electrocatalytic activity and stability of the PtAuRu/RGO catalyst for the methanol oxidation reaction are superior to those of PtAu/RGO, PtRu/RGO and Pt/RGO catalysts. These findings suggest that the prepared PtAuRu/RGO catalyst has great potential for use in direct methanol fuel cells (DMFCs).
Co-reporter:Ruirui Yue, Qiang Zhang, Caiqin Wang, Yukou Du, Ping Yang, Jingkun Xu
Electrochimica Acta 2013 Volume 107() pp:292-300
Publication Date(Web):30 September 2013
DOI:10.1016/j.electacta.2013.06.021
•Electropolymerization of 5-aminoindole (AIn) in the presence of graphene (GE).•Significant catalytic effect of GE on the polymerization of AIn.•PAIn/GE/GC used as Pt catalyst support.•The enhanced catalytic activity of Pt/PAIn/GE/GC for methanol electrooxidation.5-Aminoindole (AIn) was electropolymerized on graphene (GE) modified glass carbon (GC) electrode in 0.5 M H2SO4 aqueous solution containing 0.01 M AIn. Because of the catalytic effect of GE, the polymerization efficiency of AIn and the electrochemical activity of as-formed poly(5-aminoindole) (PAIn) were significantly improved on GE/GC electrode as compared to that on the bare GC electrode. The prepared PAIn/GE/GC electrode was used as substrate for Pt particle electrodeposition. SEM, EDX and Raman spectral were used to characterize the prepared electrodes. Electrocatalytic experiments demonstrate that the Pt/PAIn/GE/GC electrode possesses high catalytic activity toward methanol electrooxidation in alkaline medium, due to the good dispersion of Pt particles on PAIn/GE/GC and the electronic interactions between the metal particles and the polymer matrixes. Thus, PAIn can be a promising alternative for polymeric catalyst support in direct alcohol fuel cells.
Co-reporter:Ruirui Yue, Caiqin Wang, Fengxing Jiang, Huiwen Wang, Yukou Du, Jingkun Xu, Ping Yang
International Journal of Hydrogen Energy 2013 Volume 38(Issue 29) pp:12755-12766
Publication Date(Web):30 September 2013
DOI:10.1016/j.ijhydene.2013.07.074
•Conducting polymers without heteroatoms in the main chain used as catalyst supports.•Polyfluorenes with hydroxyl and carboxyl substitution used as supports for Pt–Pd.•Significant impact of the carboxyl group on the enhancing catalytic activity.•The highest catalytic activity of Pt–Pd/poly(9-fluorenecarboxylic acid) composite.A series of novel Pt–Pd/polyfluorenes (PFs) composite catalysts were facilely prepared based on Pt/Pd precursor and PFs with hydroxyl and carboxyl substitution at the C-9 position by electrochemical method and their electrocatalytic performance toward formic acid oxidation were studied. Electrocatalytic experiments demonstrate that the Pt–Pd nanoparticles immobilized on poly(9-fluorenecarboxylic acid) (PFCA)-decorated glassy carbon (GC) electrode (Pt–Pd/PFCA/GC) show larger electrochemical active surface area, higher catalytic activity and stability toward formic acid oxidation than that of other Pt–Pd/PFs/GC, Pt–Pd/GC, as well as the commercial JM 20% Pt/C/GC electrodes, which can be attributed to the small-sized and well-dispersed Pt–Pd nanoparticles on PFCA matrix and the special electronic interaction between the metal nanoparticles and the polymer substrate. Moreover, the electron-withdrawing carboxyl substitution rather than the electron-donating hydroxyl on the polymer main chain is of great benefit to the removal of poison CO as well as the enhancement of catalytic activity of Pt–Pd toward formic acid oxidation.
Co-reporter:Zhangquan Yao, Ruirui Yue, Chunyang Zhai, Fengxing Jiang, Huiwen Wang, Yukou Du, Chuangyi Wang, Ping Yang
International Journal of Hydrogen Energy 2013 Volume 38(Issue 15) pp:6368-6376
Publication Date(Web):20 May 2013
DOI:10.1016/j.ijhydene.2013.02.140
•Electrochemical fabrication of N–Pt/RGO/CF electrode.•Large surface area and unique three-dimensional pore structure.•Enhanced catalytic activity and stability toward methanol electrooxidation.Here, we report a novel method for assembling reduced graphene oxide (RGO) and Pt nanoparticles on a carbon fiber (CF) electrode successively to form a stable Pt nanoparticle-RGO-Pt nanoparticle-RGO/CF multiple junction for electrocatalysis application. As the SEM imaging exhibited, Pt nanoparticles are uniformly deposited on the surface of each RGO sheet, performing an alternative covering structure of RGO and Pt nanoparticle multi-layer on the CF electrode. Thus, a novel three-dimensional (3D) multi-layered Pt/RGO modified CF electrode (N–Pt/RGO/CF) is obtained. Experimental results demonstrate that the prepared N–Pt/RGO/CF electrode shows good electrochemical properties and enhanced electrocatalytic activity toward methanol electrooxidation in alkaline medium as compared with the Pt/RGO/CF electrode without layer-by-layer structure or the Pt/CF electrode without RGO. It is due to the unique 3D pore structure of N–Pt/RGO/CF and the good electron transport property of RGO in the composite electrode.
Co-reporter:Zhangquan Yao;Ruirui Yue;Fengxing Jiang
Journal of Solid State Electrochemistry 2013 Volume 17( Issue 9) pp:2511-2519
Publication Date(Web):2013 September
DOI:10.1007/s10008-013-2130-3
A simple electrochemical approach is developed to prepare reduced graphene oxide (RGO)-wrapped carbon fiber (CF) as a novel support for Pt–Au nanocatalysts. The obtained composite electrodes have been characterized by scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDX), thermal gravimetric analysis (TGA), and electrochemical methods. SEM images reveal that the Pt–Au nanoparticles deposited on RGO-wrapped CF (RGO/CF) electrode display smaller particle size and more uniform dispersion than those on the bare CF electrode. Cyclic voltammetry, linear sweep voltammetry, chronoamperometry, chronopotentiometry, Tafel plots, and electrochemical impedance spectroscopy (EIS) analyses demonstrate that the introduced RGO on CF electrode surface is beneficial to the dispersion of Pt–Au nanoparticles, as a consequence, to the enhancement of the electrocatalytic activity and the antipoisoning ability of Pt–Au towards formic acid electrooxidation.
Co-reporter:Fengxing Jiang;Zhangquan Yao;Ruirui Yue
Journal of Solid State Electrochemistry 2013 Volume 17( Issue 4) pp:1039-1047
Publication Date(Web):2013 April
DOI:10.1007/s10008-012-1961-7
The support materials play a critical role for the electrocatalytic oxidation of ethanol on precious metal catalysts in fuel cells. Here, we report the poly(3,4-ethylenedioxythiophene) combined with reduced graphene oxide (PEDOT-RGO) as the support of Pd nanoparticles (NPs) for ethanol electrooxidation in alkaline medium. The as-prepared Pd/PEDOT-RGO composite catalysts are characterized by Raman spectrometer, X-ray diffraction, transmission electron microcopy, and scanning electron microcopy. PEDOT-RGO composite with the porous structure facilitates the dispersion of Pd NPs with a smaller size leading to the increase of electrochemical active surface area. The electrochemical properties and electrocatalytic activities of Pd/PEDOT-RGO hybrid are evaluated by cyclic voltammetry, chronoamperometry, CO stripping voltammetry, electrochemical impedance spectroscopy (EIS) and Tafel analysis. The results suggest that Pd/PEDOT-RGO hybrid shows a higher electrocatalytic activity, a better long-term stability, and the poisoning tolerance for the ethanol electrooxidation than Pd on carbon black. EIS and Tafel analysis indicate that PEDOT-RGO improves the kinetics of ethanol electrooxidation on the Pd NPs and is an efficient support in fuel cells.
Co-reporter:Fengxing Jiang, Ruirui Yue, Yukou Du, Jingkun Xu, Ping Yang
Biosensors and Bioelectronics 2013 Volume 44() pp:127-131
Publication Date(Web):15 June 2013
DOI:10.1016/j.bios.2013.01.003
We developed a novel nonenzymatic biosensor based on palladium/poly(3,4-ethylenedioxythiophene) (Pd/PEDOT) nanocomposite modified glassy carbon electrode (GCE) for the detection of hydrogen peroxide (H2O2). Pd/PEDOT has been successfully fabricated by a facile one-pot ‘green’ method using H2PdCl4 as an oxidant and a source of metal nanoparticles without any surfactants and templates. The as-synthesized PEDOT nanospheres are quite uniform in size (∼60 nm) without aggregation and provide a good platform for anchoring the Pd nanoparticles (NPs). Pd NPs (∼4.5 nm) are homogenously dispersed on surface of PEDOT nanospheres. The Pd/PEDOT nanospheres on GCE exhibit a good electrocatalytic activity towards the H2O2 reduction. The electrochemical response of Pd/PEDOT to H2O2 exhibits a low detection limit of 2.84 μM in the range of 2.5×10−3–1.0 mM with a high sensitivity, good repeatability, acceptable reproducibility and good long-term stability. The good recoveries achieved in spiked human urine samples demonstrated the potential application of Pd/PEDOT for H2O2 detection.Graphical abstractHighlights► One-pot facile synthesis of Pd-decorated homogeneous PEDOT nanospheres. ► No any surfactant and template to be used. ► 3D porous nanostructure for Pd/PEDOT nanospheres. ► Well-dispersed Pd nanoparticles on PEDOT nanospheres. ► High sensitivity and low detection limit for Pd/PEDOT as H2O2 sensor.
Co-reporter:Huiwen Wang, Jiao Du, Zhangquan Yao, Ruirui Yue, Chunyang Zhai, Fengxing Jiang, Yukou Du, Chuanyi Wang, Ping Yang
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2013 Volume 436() pp:57-61
Publication Date(Web):5 September 2013
DOI:10.1016/j.colsurfa.2013.06.020
•The Pt–RuNPs/RGO/CCE was fabricated by electrochemical method.•Pt–Ru nanoparticles deposited on RGO appear to be well-dispersed.•The Pt–RuNPs/RGO/CCE shows high catalytic activity for methanol electrooxidation.A facile electrochemical method to fabricate reduced graphene oxide (RGO) wrapped carbon cloth (CC) as a novel support for anchoring Pt–Ru nanocatalysts is reported. The obtained composite electrodes have been characterized by scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDX) and electrochemical methods. It is found that the Pt–Ru nanoparticles electro-deposited are smaller and more uniformly dispersed on RGO wrapped CC electrode (CCE) than those on the bare CCE. The introduction of RGO on CCE surface is beneficial to the dispersion of Pt–Ru nanoparticles, leading to the enhanced electro-catalytic activity and anti-poisoning ability of Pt–Ru toward methanol electro-oxidation.
Co-reporter:Jiao Du, Ruirui Yue, Zhangquan Yao, Fengxing Jiang, Yukou Du, Ping Yang, Chuanyi Wang
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2013 Volume 419() pp:94-99
Publication Date(Web):20 February 2013
DOI:10.1016/j.colsurfa.2012.11.060
A facile and cost effective approach has been developed towards electrochemical fabrication of graphene-modified carbon fiber electrode (GE/CFE) to determine the content of uric acid (UA) via cyclic voltammetry (CV) and potentiostatic (i–t) methods. The combined merits of GE and CFE endow the electrode with large specific surface area and high electrical conductivity. The advantage of thus obtained GE/CFE for UA detection is supported by its higher peak current intensity and lower oxidation potential compared with those of bare glassy carbon electrode (GCE), bare carbon fiber electrode (CFE), and graphene-modified glassy carbon electrode (GE/GCE). Further amperometric study gives a wide liner range from 0.194 μM to 49.68 μM and a low detection limit of 0.132 μM (S/N = 3) with fast response time for the determination of UA on GE/CFE. The determination of UA with GE/CFE is highly selective and reproducible, within a relative standard deviation of 2.8%.Highlights► A facile and cost effective electrode, graphene modified carbon fiber electrode (GE/CFE), was used for UA detection. ► The GE/CFE shows high electron transport capacity due to the perfect structure and package effect between GE and CFE. ► The GE/CFE shows high selectivity, good responsiveness and fast response for UA detection.
Co-reporter:Jiao Du;Ruirui Yue;Fangfang Ren;Zhangquan Yao;Fengxing Jiang
Gold Bulletin 2013 Volume 46( Issue 3) pp:137-144
Publication Date(Web):2013 September
DOI:10.1007/s13404-013-0090-0
A novel layer-by-layer assembly of graphene sheets and gold nanoparticles modified carbon fiber electrode (GE/Au/GE/CFE) was successfully fabricated and applied to simultaneous determination of dopamine (DA) and uric acid (UA). The structure of GE/Au/GE/CFE was characterized by scanning electron microscopy (SEM). It was observed that the gold nanoparticles were homogeneously assembled between the two layers of GE sheets. Cyclic voltammetry (CV) measurements elucidate that GE/Au/GE/CFE has higher electrocatalytic activity for the oxidation of DA and UA when compared with graphene modified carbon fiber electrode (GE/CFE), and graphene and gold nanoparticles modified carbon fiber electrode (Au/GE/CFE). Simultaneous determination of UA and DA on GE/Au/GE/CFE was conducted with a differential pulse voltammetry technique, and two well-defined and fully resolved anodic oxidation peaks were observed. Anodic oxidation currents of DA and UA are linear with their concentration in the range of 0.59–43.96 μM and 12.6–413.62 μM, respectively. Moreover, the composite electrode displays high reproducibility and selectivity for the determination of UA and DA.
Co-reporter:Qiang Zhang;Ruirui Yue;Fengxing Jiang;Huiwen Wang;Chunyang Zhai
Gold Bulletin 2013 Volume 46( Issue 3) pp:175-184
Publication Date(Web):2013 September
DOI:10.1007/s13404-013-0098-5
The absence of unpaired d-electrons of gold leads to its lack of reactivity and paucity of catalytic activity. Synergistic activity of bimetallic PtAu has been proved, and its structure greatly influences on the electrocatalytic activity toward formic acid and carbon monoxide oxidation. Here, a comparison between Pt-modified Au (designated as Pt-on-Au) and PtAu alloy catalysts has been studied. The Pt-on-Au catalyst was prepared by electrodeposition of Pt on the pre-prepared Au, while PtAu alloy was obtained by co-electrodeposition. As a whole, both types of PtAu catalysts were found to be more active toward formic acid electrooxidation compared to pure Pt, exhibiting maximum activity on Pt-on-Au catalyst with Pt to Au atomic ratio of 1:10.22. Moreover, the Pt/Au atomic ratio directly relates to the oxidation pathway of formic acid and carbon monoxide oxidation. The results may be ascribed to much less COads on the surface than single Pt catalyst due to the effect of Au nanoparticles. CO stripping voltammograms present the obvious variation between Pt-on-Au and PtAu alloy catalysts. Meanwhile, the electrocatalytic activities of bimetallic PtAu are evaluated by electrochemical impedance spectroscopy and Tafel analysis.
Co-reporter:Zhangquan Yao, Mingshan Zhu, Fengxing Jiang, Yukou Du, Chuanyi Wang and Ping Yang
Journal of Materials Chemistry A 2012 vol. 22(Issue 27) pp:13707-13713
Publication Date(Web):10 May 2012
DOI:10.1039/C2JM31683H
In this paper, a facile electrochemical approach is developed towards synthesizing Pt nanoflowers modified reduced graphene oxide (RGO) wrapped carbon cloth (CC) as an anode (Pt nanoflowers/RGO/CCE) for formic acid and methanol electrooxidation. As revealed by SEM measurements, the carbon cloth is well wrapped by the RGO, and the RGO wrapped carbon cloth serves as an excellent support for electrochemically anchoring Pt nanoflowers, being more well-dispersed than without RGO. Compared with Pt nanoparticles/CCE, Pt nanoparticles/RGO/CCE, and Pt nanoflowers/CCE, the Pt nanoflowers/RGO/CCE displays a distinctly enhanced current density of CVs towards formic acid and methanol electrooxidation. The utilization of graphene results in well-dispersed Pt nanostructures with a uniform size and unique morphology structure; a relatively large surface area; and excellent electron or charge transfer rate, contributing to the enhanced electrocatalytic activity. The work likely opens up new promise for developing novel, low-cost yet highly efficient carbon material-based electrodes, especially for direct formic acid fuel cells and direct methanol fuel cells.
Co-reporter:Ruirui Yue, Fengxing Jiang, Yukou Du, Jingkun Xu, Ping Yang
Electrochimica Acta 2012 Volume 77() pp:29-38
Publication Date(Web):30 August 2012
DOI:10.1016/j.electacta.2012.05.150
A novel conducting polymer, poly(5-aminoindole) (PAIn), one of polyindole derivatives, has been electrosynthesized by potentiodynamic method in 0.5 M H2SO4 aqueous solution containing 0.02 M 5-aminoindole (AIn). As-synthesized polymer films show good electrochemical activity and stability in aqueous solution. 1H NMR, UV–visible and emission spectral analyses confirmed the formation of the polymer with conjugated chain structure and that the polymerization mainly occurred at C(2) and C(3) positions with NH2 and NH remaining intact. Based on as-prepared PAIn, a composite catalyst has been synthesized via electrodepositing Pt micro/nano-particles on the polymer modified carbon cloth (CC) electrode. As-formed composite catalysts were characterized by SEM, EDX and electrochemical analyses. Compared with pure Pt particles, the Pt/PAIn composite catalyst deposited on CC electrode (denoted as Pt/PAIn/CC) shows higher catalytic activity and stronger poisoning-tolerance for formic acid electrooxidation. Electrochemical impedance spectroscopy shows that the charge-transfer resistance for formic acid electrooxidation on Pt/PAIn/CC is smaller than that on Pt/CC. The present study shows a promising conducting polymer, PAIn, used as the catalyst support for formic acid electrooxidation, and further work on improving the catalytic activity of the composite catalyst is under way.Highlights► PAIn was electrosynthesized in aqueous solution. ► As-synthesized polymer shows good electrochemical activity and stability. ► Pt particles were electrodeposited on PAIn film to prepare a composite catalyst. ► The composite catalyst shows high catalytic activity for formic acid oxidation.
Co-reporter:Fengxing Jiang, Zhangquan Yao, Ruirui Yue, Yukou Du, Jingkun Xu, Ping Yang, Chuanyi Wang
International Journal of Hydrogen Energy 2012 Volume 37(Issue 19) pp:14085-14093
Publication Date(Web):October 2012
DOI:10.1016/j.ijhydene.2012.04.084
Layered electrochemically reduced graphene oxide (ER-GO) sheets incorporated with poly(3,4-ethylenedioxythiophene) (PEDOT) have been fabricated as an efficient support for Pt nanoparticles on a glassy carbon (GC) electrode. The as-prepared Pt-loaded PEDOT/ER-GO composite electrode exhibits not only the high mass peak current density (390 A g−1) but also the good long-term catalytic stability toward the ethanol electrooxidation. The Pt/PEDOT/ER-GO also shows stronger tolerance to poisoning species compared with the commercial JM 20% Pt/C electrode. The high electrocatalytic activity of Pt/PEDOT/ER-GO is mainly described to the good electrochemical activity of PEDOT/ER-GO composites and the well-dispersed Pt nanoparticles resulting in the large electrochemical active surface area of Pt (47.1 m2 g−1).Highlights► Electrochemical fabrication of ternary composite catalyst Pt/PEDOT/ER-GO. ► Well-dispersed Pt nanoparticles on PEDOT/ER-GO. ► Enhanced catalytic activity toward ethanol electrooxidation on Pt/PEDOT/ER-GO. ► Good long-term electrocatalytic stability of Pt/PEDOT/ER-GO.
Co-reporter:Fengxing Jiang, Fangfang Ren, Weiqiang Zhou, Yukou Du, Jingkun Xu, Ping Yang, Chuanyi Wang
Fuel 2012 Volume 102() pp:560-566
Publication Date(Web):December 2012
DOI:10.1016/j.fuel.2012.07.008
Pt-based catalysts with free-standing poly[poly(N-vinyl carbazole)] (PPVK) as support (Pt–M/PPVK, M = Pd, Au, and Ru) on a glassy carbon electrode (GCE) have been successfully prepared by an electrochemical method. Cyclic voltammetric and chronoamperometric methods are used to investigate the electrocatalytic activity and stability of as-prepared catalysts. It is found that PPVK film as support effectively enhances the catalytic acitivity of Pt nanoparticles for methanol electro-oxidation in alkaline medium. The bimetallic Pt–M nanoparticles obtained potentiostatically on the PPVK film show the higher electrocatalytic activity than bare Pt/GCE and JM Pt/C. In addition, to pin down the external influencing factors, systematic studies have been conducted on the methanol electro-oxidation at as-prepared catalysts as a function of platinum loading, PPVK mass, methanol and KOH concentrations.Highlights► Free-standing conducting polymer PPVK as a support of Pt-based catalyst. ► PPVK-supported Pt-based catalysts exhibit enhanced catalytic activity and stability. ► PPVK as support improves the poisoning tolerance of catalyst.
Co-reporter:Weiqiang Zhou, Chuanyi Wang, Jingkun Xu, Yukou Du, Ping Yang
Journal of Power Sources 2011 Volume 196(Issue 3) pp:1118-1122
Publication Date(Web):1 February 2011
DOI:10.1016/j.jpowsour.2010.08.053
Self-assembly of Pt and indole into a novel composite catalyst on a glassy carbon electrode (GC) has been developed by a one-step electrodeposition in the presence of 3.0 mM H2PtCl6 and 0.1 mM indole. Compared to Pt/GC and Pt/C, the novel Pt–indole composite catalyst exhibits higher catalytic activity and stronger poisoning tolerance for electrooxidation of formic acid. The adsorption strength of CO on the prepared Pt–indole composite catalyst is greatly weakened as demonstrated by CO stripping voltammograms. Because of its advantageous catalytic activity and poisoning tolerance, the novel Pt–indole composite catalyst is anticipated to find interesting applications in many important fields such as energy and catalysis.
Co-reporter:Hongmei Zhang, Fengxing Jiang, Rong Zhou, Yukou Du, Ping Yang, Chuanyi Wang, Jingkun Xu
International Journal of Hydrogen Energy 2011 Volume 36(Issue 23) pp:15052-15059
Publication Date(Web):November 2011
DOI:10.1016/j.ijhydene.2011.08.072
In fuel cells, Pt is often employed as an electrode material to facilitate electrochemical reaction processes, in which morphology plays an important role. In this work, three kinds of Pt flowers have been prepared on a glassy electrode substrate via a facile electrochemical deposition in a solution of H3PO4; by controlling work potentials at −0.1 V, −0.2 V and −0.3 V, cauliflower-like, needle-like and rose-like shapes of Pt micro/nanoparticles as confirmed by SEM and XRD are obtained, respectively. Taking methanol oxidation as a model reaction and using CO stripping voltammogram in an acid medium, the electrocatalytic performance of as-prepared three Pt flowers has been evaluated. The three Pt flowers show different electrocatalytic activities, and the needle-like Pt flowers present the highest catalytic activity for electrooxidation of methanol and CO.Highlights► Facile fabrication of cauliflower-like, needle-like and rose-like Pt micro/nanoparticles modified GC electrode. ► Varying the applied potential was found to affect the surface morphologies of Pt. ► The formed mechanism of different morphologies Pt was presented. ► Needle-like Pt flowers displayed the best electrocatalytic activity and stability.
Co-reporter:Weiqiang Zhou, Jingkun Xu, Yukou Du, Ping Yang
International Journal of Hydrogen Energy 2011 Volume 36(Issue 3) pp:1903-1912
Publication Date(Web):February 2011
DOI:10.1016/j.ijhydene.2010.11.023
Electrocatalytic activities of the monometallic Pt and bimetallic Pt–Ru nanoparticles dispersed onto polycarbazole (PCZ) films obtained by the electropolymerization on glassy carbon electrode (GC) (i.e., Pt/PCZ/GC, Pt–Ru/PCZ/GC) towards formic acid oxidation have been investigated using cyclic voltammetry and chronoamperometry methods. As-formed electrodes are characterized by SEM, EDX and electrochemical analysis. Relative to Pt and Pt–Ru deposited on the bare GC (i.e., Pt/GC and Pt–Ru/GC), Pt/PCZ/GC and Pt–Ru/PCZ/GC, respectively, exhibit higher catalytic activity and stronger poisoning-tolerance ability towards formic acid electrooxidation. The enhanced performance is proposed to come from the synergetic effect between metal nanoparticles (Pt, Pt–Ru) and PCZ. At the same time, the results of the stripping voltammograms of CO show that PCZ can weaken largely the adsorption strength of CO on catalysts and can make CO oxidation easier under lower potential, implying further that PCZ can be used as an efficient promoter for electrocatalytic oxidation of formic acid on Pt/PCZ and Pt–Ru/PCZ catalysts.Research highlights►Pt, Pt-Ru supported on polycarbazole (PCZ) are prepared and used for formic acid electrooxidation. ► PCZ modified Pt and Pt-Ru catalysts exhibit superior electrocatalytic activities. ► PCZ modified Pt and Pt-Ru catalysts mitigate the COads-like poisoning.
Co-reporter:Fangfang Ren, Weiqiang Zhou, Yukou Du, Ping Yang, Chuanyi Wang, Jingkun Xu
International Journal of Hydrogen Energy 2011 Volume 36(Issue 11) pp:6414-6421
Publication Date(Web):June 2011
DOI:10.1016/j.ijhydene.2011.02.143
A Pt-based composite electrode material has been developed by dispersing Pt nanoparticles on a porous poly(o-methoxyaniline) (POMA) film, which was produced via electropolymerization on a glassy carbon (GC) electrode. As-formed Pt/POMA/GC electrode was characterized by SEM, EDX and electrochemical analysis. Furthermore, the composite electrode material was evaluated by its electrocatalytic performance for formic acid oxidation using cyclic voltammetry and chronoamperometry methods. Compared to Pt deposited on bare GC (Pt/GC), Pt/POMA/GC exhibits higher catalytic activity and stronger poisoning-tolerance ability towards formic acid electro-oxidation. The improved performance is attributed to the synergetic effect between Pt and POMA. Also, as demonstrated by CO stripping voltammograms, the interference of CO on Pt/POMA/GC is greatly weakened. These results suggest that the POMA film has great potential to serve as a promising support material for the electrocatalytic oxidation of formic acid.
Co-reporter:Weiqiang Zhou, Yukou Du, Hongmei Zhang, Jingkun Xu, Ping Yang
Electrochimica Acta 2010 Volume 55(Issue 8) pp:2911-2917
Publication Date(Web):1 March 2010
DOI:10.1016/j.electacta.2010.01.017
Four novel composite catalysts have been developed by the electrodeposition of Pt onto glassy carbon electrode (GCE) modified with polyindoles: polyindole, poly(5-methoxyindole), poly(5-nitroindole) and poly(5-cyanoindole). As-formed composite catalysts are characterized by SEM, XRD and electrochemical analysis. Compared with Pt nanoparticles, respectively, deposited on the bare GCE and on the GCE modified with polypyrrole, the four newly developed composite catalysts exhibit higher catalytic activity towards formic acid electrooxidation by improving selectivity of the reaction via dehydrogenation pathway and thus mostly suppressing the generation of poisonous COads species. The enhanced performance is proposed to come from the synergetic effect between Pt and polyindoles and the increase of electrochemical active surface area (EASA) of Pt on polyindoles.
Co-reporter:Hongmei Zhang, Weiqiang Zhou, Yukou Du, Ping Yang, Chuanyi Wang
Electrochemistry Communications 2010 Volume 12(Issue 7) pp:882-885
Publication Date(Web):July 2010
DOI:10.1016/j.elecom.2010.04.011
A facile, one-step and template-free electrodeposition method has been developed for the first time to prepare porous Pt nanoflowers. The flowerlike architectures were confirmed by SEM, and further structurally characterized by XRD and electrochemical analyses. Compared to conventional nanosized Pt catalysts, as-prepared Pt nanoflowers exhibit remarkably higher catalytic activity and stronger poisoning-tolerance for the methanol electro-oxidation, and thus they are anticipated to find interesting applications in many important fields such as energy and catalysis.
Co-reporter:Weiqiang Zhou, Yukou Du, Fangfang Ren, Chuanyi Wang, Jingkun Xu, Ping Yang
International Journal of Hydrogen Energy 2010 Volume 35(Issue 8) pp:3270-3279
Publication Date(Web):April 2010
DOI:10.1016/j.ijhydene.2010.01.083
Novel composite catalysts have been fabricated by the electrodeposition of Pt onto the glassy carbon electrode (GC) modified respectively with polyindole (PIn) and poly(5-methoxyindole) (PMI) and used for the electrooxidation of methanol in acid solution of 0.5 M H2SO4 containing 1.0 M methanol. As-formed composite catalysts are characterized by SEM, XRD and the electrochemical methods. The results of the catalytic activity for methanol oxidation show that the two composite catalysts exhibit higher catalytic activity and stronger poisoning-tolerance than Pt/polypyrrole/GC (Pt/PPy/GC) and Pt/GC. Electrochemical impedance spectroscopy indicates that the methanol electrooxidation on the composite catalysts at various potentials shows different impedance behaviors. At the same time, the charge-transfer resistance for electrooxidation of methanol on Pt/PIn/GC and Pt/PMI/GC is smaller than those on Pt/PPy/GC and Pt/GC. The present study shows a promising choice of Pt/PIn and Pt/PMI as composite catalysts for methanol electrooxidation.
Co-reporter:Hongmei Zhang, Weiqiang Zhou, Yukou Du, Ping Yang, Chuanyi Wang, Jingkun Xu
International Journal of Hydrogen Energy 2010 Volume 35(Issue 24) pp:13290-13297
Publication Date(Web):December 2010
DOI:10.1016/j.ijhydene.2010.09.025
Pt is one of the most important electrode materials employed in direct methanol fuel cell, and many efforts have been directed to improving its electrocatalytic performance. In this work, Pt–TiO2 nanocomposites are successfully prepared by a sol–gel method. As revealed by TEM, Pt nanoparticles with an average size of 2.6 nm are well uniformly dispersed on porous TiO2. XRD structural characterization indicates that Pt possesses a face centered cubic crystal structure while TiO2 is in the format of both rutile and anatase phases. The electrochemical performance of as-prepared nanocomposite electrode (Pt–TiO2/ITO) is evaluated by studying the electrocatalytic oxidation of methanol in an alkaline medium with or without UV illumination. Comparative experiments evince that the electrochemical performance of Pt–TiO2/ITO for methanol electrooxidation is markedly improved under UV illumination. Under UV illumination, moreover, the poisoning resistance of Pt–TiO2/ITO for methanol electrooxidation is significantly improved, as supported by the results of time-coursed current measurements.
Co-reporter:Weiqiang Zhou, Jing Wang, Chuanyi Wang, Yukou Du, Jingkun Xu, Ping Yang
Materials Chemistry and Physics 2010 Volume 122(Issue 1) pp:10-14
Publication Date(Web):1 July 2010
DOI:10.1016/j.matchemphys.2010.02.059
Recyclability of noble metal catalysts is a challenging issue when dealing with their industrial applications. Smart pH-sensitive Pt nanoparticles were successfully prepared for the first time by using octa(N,N-diacetic acid phenylamine)silsesquioxane (OAPAS) as a macromolecular protective agent. As-prepared Pt nanoparticles can self-aggregate or redisperse by only changing the pH of the system solution. In the weak acidic or alkaline solution (pH > 4.0), the Pt nanoparticles dispersed homogenously; while in the acidic solution (pH = 2.5), they self-aggregated. The dynamic self-aggregation and redispersion processes of the Pt nanoparticles driven by pH changes were revealed by transmission electron microscopy measurements. Electrocatalytic experiments proved that the platinum nanoparticles as a recyclable catalyst showed excellent activity for the hydrogenation of aldehyde after runs of five times. Such platinum nanoparticles are thereby anticipated to have great potential functioning as “smart” catalysts for industrial applications.
Co-reporter:Weiqiang Zhou, Chuanyi Wang, Jingkun Xu, Yukou Du, Ping Yang
Materials Chemistry and Physics 2010 Volume 123(2–3) pp:390-395
Publication Date(Web):1 October 2010
DOI:10.1016/j.matchemphys.2010.04.027
Poly(p-phenylene) (PPP) films with good electrochemical activity and good thermal stability were synthesized by a low-potential electrochemical polymerization of biphenyl in pure boron trifluoride diethyl etherate. As-formed PPP film was firstly used as a catalyst support. Pd–Au nanoparticles were successfully electro-deposited on PPP films (namely, Pd–Au/PPP) and used for the electrooxidation of isopropanol in alkaline media. The Pd–Au/PPP composite catalyst shows a high electrochemical active surface area in the hydrogen adsorption potential region. The results for isopropanol oxidation indicate that Pd–Au/PPP have higher catalytic activity and stronger poisoning-resistance than the Pd–Au deposited on the bare electrode. Furthermore, the role of PPP in the composite catalyst and supplemental effect are discussed. The present study evidences that Pd–Au/PPP is a promising choice as a composite catalyst for isopropanol electrooxidation in alkaline medium.
Co-reporter:Chao Wei;Weiqiang Zhou;Jingkun Xu;Ping Yang
Colloid Journal 2010 Volume 72( Issue 2) pp:158-162
Publication Date(Web):2010 April
DOI:10.1134/S1061933X1002002X
Multicore-shell CdS-Si02 nanoparticles were synthesized in AOT/heptane/H2O reverse micelles at room temperature. CdS-SiO2 nanoparticles were characterized by UV-vis spectroscopy, TEM, and SEM methods. The results show that multicore-shell composites were formed. Fluorescence properties of composites were also investigated; the data imply that fluorescence properties of the silica-coated CdS nanoparticles were significantly improved when compared to those of the non-coated CdS nanoparticles. The stability of multicore-shell CdS-SiO2 nanoparticles upon the UV irradiation was higher than that of non-coated CdS nanoparticles.
Co-reporter:Hongmei Zhang;Weiqiang Zhou;Jingkun Xu
Journal of Materials Science 2010 Volume 45( Issue 21) pp:5795-5801
Publication Date(Web):2010 November
DOI:10.1007/s10853-010-4654-6
Composite films of poly(o-methoxyaniline) (POMA) and carbon nanotubes (CNTs) were prepared via electrochemical co-deposition from the aqueous solutions containing o-methoxyaniline and acid-treated CNTs. The addition of small amounts of CNTs to o-methoxyaniline can accelerate significantly the electrochemical polymerization rate of the monomer. As-prepared composite films are characterized by thermal analysis, SEM, and the electrochemical methods. The results of the thermal analysis show that the composites have an enhanced thermal stability relative to POMA. SEM revealed that CNTs had been uniformly coated with POMA, forming dense nanoporous networks composite films.
Co-reporter:Weiqiang Zhou, Chunyang Zhai, Yukou Du, Jingkun Xu, Ping Yang
International Journal of Hydrogen Energy 2009 Volume 34(Issue 23) pp:9316-9323
Publication Date(Web):December 2009
DOI:10.1016/j.ijhydene.2009.09.059
A novel composite catalyst, Pt nanoparticles supported on poly(5-nitroindole) (Pt/PNI), has been successfully prepared by the electrochemical method and used for the electrooxidation of methanol in alkaline media. As-prepared Pt/PNI was characterized by SEM, EDX and electrochemical methods. The results of the catalytic activity for methanol oxidation showed that Pt/PNI had higher catalytic activity and stronger poisoning-tolerance than Pt/Pt, Pt/GC and the common Pt electrode. The effects of different parameters related to the methanol oxidation reaction kinetics, such as Pt loading, mass of PNI film, concentration of methanol and KOH, potential scan rate, have also been investigated. The present study showed a promising choice of Pt/PNI as composite catalyst for methanol electrooxidation in alkaline medium.
Co-reporter:Chunyang Zhai;Chao Wei;Jingkun Xu;Ping Yang
Colloid Journal 2009 Volume 71( Issue 6) pp:
Publication Date(Web):2009 December
DOI:10.1134/S1061933X09060052
1,8-naphthalimide-labelled polyamidoamine dendrimer (PAMAM-N) was synthesized and used to stabilize Au and Ag nanoparticles, which were characterized by UV-Vis absorption and fluorescence spectroscopies, and transmission electron microscopy. The dimensions of Au and Ag nanoparticles protected by PAMAM-N were smaller and the size distribution was narrower when compared to those of polyamidoamine dendrimer. The presence of chromophore fragment (1,8-naphthalimide) allowed the fluorescent labeling of Au and Ag nanoparticles.
Co-reporter:Mingchun Du;Ying Wang;Jingkun Xu;Ping Yang
Colloid Journal 2008 Volume 70( Issue 6) pp:720-725
Publication Date(Web):2008 December
DOI:10.1134/S1061933X08060069
A novel approach to preparing PbSe quantum dots in a high-boiling-point solvent (paraffin liquid) was studied. PbSe quantum dots obtained were transferred from the organic phase to aqueous phase. The PbSe samples were characterized by transmission electron microscopy, X-ray diffraction, and energy dispersive X-ray analysis, which demonstrated that high-quality PbSe quantum dots with regular shape and uniform size were prepared. The mechanism of PbSe quantum dot formation was briefly discussed.
Co-reporter:Yukou Du, Yuqin Gan, Ping Yang, Zou Cuie, Nanping Hua
Materials Chemistry and Physics 2007 Volume 103(2–3) pp:446-449
Publication Date(Web):15 June 2007
DOI:10.1016/j.matchemphys.2007.02.063
Undoped and Mo(VI) ions doped TiO2 thin films were prepared via sol–gel method on different substrates. The morphology and the crystalline structures of the thin films were studied by SEM and XRD. The UV light inducing hydrophilicity was improved by doping Mo(VI) ions. The influence of the dopant density on the photo-induced superhydrophilicity of the films was investigated using cyclic voltammetry. A new oxidation peak was observed at about 0.17 V when the TiO2 electrodes were irradiated by UV light for a certain time. The peak current increased with the irradiation time. To reach the same peak current, 0.75% Mo(VI) ions doped films required short time than the undoped film.
Co-reporter:Y. Du;M. Du;Y. Qiao;J. Dai;J. Xu;P. Yang
Colloid Journal 2007 Volume 69( Issue 6) pp:695-699
Publication Date(Web):2007 December
DOI:10.1134/S1061933X0706004X
Undoped and Ce(4+) doped TiO2 thin films were prepared by sol-gel method. The samples were characterized using scanning electron microscopy, the photocatalytic reactivity was evaluated by degradation of methylene blue in the aqueous solution. 0.5 wt. % Ce(4+) doped TiO2 thin films calcined at 400°C show the highest photocatalytic activity.
Co-reporter:Y. K. Du;P. Yang;Z. G. Mou;N. P. Hua;L. Jiang
Journal of Applied Polymer Science 2006 Volume 99(Issue 1) pp:23-26
Publication Date(Web):11 OCT 2005
DOI:10.1002/app.21886
TG-DTA, TEM, and IR were used to investigate the thermal decomposition behavior of poly(N-vinyl-2-pyrrolidone) (PVP). The TG-DTA results show that the thermal decomposition behavior of PVP on platinum (Pt) is quite different from that of pure PVP. For pure PVP, 95.25% is decomposed when the temperature is increased up to 500°C; while under the same experimental condition, PVP coated on the Pt nanoparticles is only 66.7% decomposed. This is further supported by IR measurement. TEM results exhibited that the partially decomposed PVP still plays a role in stabilizing Pt nanoparticles: after heating treatment at 500°C for half an hour, the platinum nanoparticles did not aggregate heavily. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 23–26, 2006
Co-reporter:Y.K. Du, J.Z. Xu, M. Shen, P. Yang, L. Jiang
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2005 Volumes 257–258() pp:535-537
Publication Date(Web):5 May 2005
DOI:10.1016/j.colsurfa.2004.10.044
A more convenient approach to obtain decahedron of gold particles in solution through a simple chemical reaction is reported in this communication. As-prepared samples were characterized by TEM and UV–vis methods. The size of the gold decahedron is about 100 nm, which possesses a structure of multiply twinned particles (MTPs). The molar ratio of n-dodecanethiol to HAuCl4 plays a key role in forming decahedrons of gold nanoparticles.
Co-reporter:Y.K. Du, J.Z. Xu, P. Yang, N.P. Hua, L. Jiang
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2005 Volumes 257–258() pp:75-78
Publication Date(Web):5 May 2005
DOI:10.1016/j.colsurfa.2004.10.043
The catalytic behavior of platinum nanoparticles modified by iron (III) ions and 1-butanethiol was evaluated by determining the selectivity of hydrogenation of trans,trans-2,4-hexadienal, where the hydrogenation products were monitored by UV–vis spectroscopy and gas chromatograph. For the pure platinum nanoparticles, the selectivity to trans,trans-2,4-hexadienal is less than 5%; while for platinum nanoparticles modified by iron (III) ions and 1-butanethiol, the selectivity increased to 78% with a conversion of 86.5%. The enhancement in the selectivity of the reaction can be attributed to the synergic effects of iron (III) and 1-butanethiol.
Co-reporter:Y.K. Du, Y.Q. Gan, P. Yang, F. Zhao, N.P. Hua, L. Jiang
Thin Solid Films 2005 Volume 491(1–2) pp:133-136
Publication Date(Web):22 November 2005
DOI:10.1016/j.tsf.2005.06.091
Undoped and Mo ions doped TiO2 thin films were prepared by a sol–gel method on soda lime glass substrates. The obtained films were characterized by ultraviolet–visible spectroscopy, X-ray diffraction and atomic force microscopy. The heat-induced hydrophilicity of the film is enhanced by doping Mo(VI) ions. After being heated at 400 °C for 1 h, the 0.75 wt.% Mo(VI)-doped TiO2 film shows superhydrophilicity.
Co-reporter:Ke Zhang, Zhiping Xiong, Shumin Li, Bo Yan, Jin Wang, Yukou Du
Journal of Alloys and Compounds (5 June 2017) Volume 706() pp:
Publication Date(Web):5 June 2017
DOI:10.1016/j.jallcom.2017.02.179
•Cu3P/RGO -supported Pd nanoparticles have been successfully prepared.•The Pd/Cu3P/RGO hybrids exhibit enhanced electrocatalytic performance and stability.•The enhanced performance can be ascribed to the electronic structure change.Herein, we reduced PdCl42− ions on the synthetized cuprous phosphide/reduced graphene oxidation (Cu3P/RGO) hybrids to improve the catalytic activity and durability of Pd nanocrystals. In comparison with commercial Pd/C and Pd/RGO catalysts, the Pd/Cu3P/RGO exhibit high electroactivity and durability toward alcohol oxidation in alkaline medium. The enhanced catalytic performance of Pd/Cu3P/RGO is due to the high electrochemically active surface area, which can be ascribed to the interactions between Cu3P/RGO and Pd nanocrystals. The investigation of Cu3P/RGO as a promoter in alcohol electrooxidation will offer an opportunity in the field of direct alcohol fuel cells (DAFCs).
Co-reporter:Yue Feng, Duan Bin, Bo Yan, Yukou Du, Tetsuro Majima, Weiqiang Zhou
Journal of Colloid and Interface Science (1 May 2017) Volume 493() pp:
Publication Date(Web):1 May 2017
DOI:10.1016/j.jcis.2017.01.035
Porous bimetallic PdNi catalysts were fabricated by a novel method, namely, reduction of Pd and Ni oxides prepared via calcining the complex chelate of PdNi-dimethylglyoxime (PdNi-dmg). The morphology and composition of the as-prepared PdNi were investigated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Furthermore, the electrochemical properties of PdNi catalysts towards ethanol electrooxidation were also studied by electrochemical impedance spectrometry (EIS), cyclic voltammetry (CV) and chronoamperometry (CA) measurement. In comparison with porous Pd and commercial Pd/C catalysts, porous structural PdNi catalysts showed higher electrocatalytic activity and durability for ethanol electrooxidation, which may be ascribed to Pd and Ni property, large electroactive surface area and high electron transfer property. The Ni exist in the catalyst in the form of the nickel hydroxides (Ni(OH)2 and NiOOH) which have a high electron and proton conductivity enhances the catalytic activity of the catalysts. All results highlight the great potential application of the calcination-reduction method for synthesizing high active porous PdNi catalysts in direct ethanol fuel cells.
Co-reporter:Jin Wang, Beibei Yang, Jiatai Zhong, Bo Yan, Ke Zhang, Chunyang Zhai, Yukihide Shiraishi, Yukou Du, Ping Yang
Journal of Colloid and Interface Science (1 July 2017) Volume 497() pp:
Publication Date(Web):1 July 2017
DOI:10.1016/j.jcis.2017.03.011
A cubic Pd and reduced graphene oxide modified glassy carbon electrode (Pd/RGO/GCE) was fabricated to simultaneously detect dopamine (DA) and uric acid (UA) by cyclic voltammetry (CV) and different pulse voltammetry (DPV) methods. Compared with Pd/GCE and RGO/GCE, the Pd/RGO/GCE exhibited excellent electrochemical activity in electrocatalytic behaviors. Performing the Pd/RGO/GCE in CV measurement, the well-defined oxidation peak potentials separation between DA and UA reached to 145 mV. By using the differential pulse voltammetry (DPV) technique, the calibration curves for DA and UA were found linear with the concentration range of 0.45–421 μM and 6–469.5 μM and the detection limit (S/N = 3) were calculated to be 0.18 μM and 1.6 μM, respectively. Furthermore, the Pd/RGO/GCE displayed high selectivity when it was applied into the determination of DA and UA even though in presence of high concentration of interferents. Additionally, the prepared electrochemical sensor of Pd/RGO/GCE demonstrated a practical feasibility in rat urine and serum samples determination.
Co-reporter:Shumin Li, Beibei Yang, Caiqin Wang, Jin Wang, Yue Feng, Bo Yan, Zhiping Xiong, Yukou Du
Journal of Electroanalytical Chemistry (1 February 2017) Volume 786() pp:
Publication Date(Web):1 February 2017
DOI:10.1016/j.jelechem.2017.01.001
•Cu2O-Au/NG (nitrogen-doped graphene) nanocomposite was fabricated by a facile and green method.•The nanocomposite has excellent electrochemical activity towards the oxidation of rutin.•The detection range of rutin is 0.06–512.90 μM with a detection limit of 30 nM.Rutin has a broad range of physiological activities and often used clinically as therapeutic medicine on humans, and it is important to develop sensitive analytical methods for rutin determination. The nanocomposites, consisting of Cu2O, Au nanoparticles and nitrogen-doped graphene (denoted as Cu2O-Au/NG), were successfully fabricated by a facile and green method and used for highly sensitive detection of rutin. The electrochemical methods, such as cyclic voltammetry (CV) and differential pulse voltammetry (DPV) have been used to investigate the electrochemical properties of the fabricated sensors for rutin detection. The results showed that under optimal conditions, Cu2O-Au/NG/GCE exhibited highest sensitivity of 114.94 μA·mM− 1 than the other modified electrodes, and a low detection limit of 30 nM could be achieved with a linear concentration response range from 0.06 to 512.90 μM. The enhanced electrochemical performances could be attributed to the synergistic effect between Cu2O-Au and NG and the outstanding catalytic effect of the Cu2O-Au nanoparticles. Finally, the sensor was successfully used to analyze rutin tablets, showing high potential for practical applications.
Co-reporter:Ke Zhang, Caiqin Wang, Duan Bin, Jin Wang, Bo Yan, Yukihide Shiraishi and Yukou Du
Catalysis Science & Technology (2011-Present) 2016 - vol. 6(Issue 16) pp:NaN6447-6447
Publication Date(Web):2016/06/23
DOI:10.1039/C6CY00789A
Highly active self-supported Pd/P nanoparticle networks were synthesized as anode electrocatalysts for direct methanol fuel cell reactions. Transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy were used to characterize the Pd/P catalysts. The results indicated that the composition does not affect the network structure. The electrocatalytic performances of elemental Pd, Pd4/P1, Pd2/P1 and Pd1/P1 nanoparticles were examined and the experimental results indicated that the Pd2/P1 catalyst showed optimal current densities in cyclic voltammetry and chronoamperometry measurements, which may be attributed to the electronic effect and its special nanostructure, having an interconnecting net structure, good electrical conductivity and high surface area. We postulate that the present method can be used as a promising and alternative approach for the design of anode electrocatalysts in direct methanol alkaline fuel cells.
Co-reporter:Jiatai Zhong, Duan Bin, Yue Feng, Ke Zhang, Jin Wang, Caiqin Wang, Jun Guo, Ping Yang and Yukou Du
Catalysis Science & Technology (2011-Present) 2016 - vol. 6(Issue 14) pp:NaN5404-5404
Publication Date(Web):2016/03/16
DOI:10.1039/C6CY00140H
In this study, highly active Au-decorated Pd heterogeneous nanocubes with Pd/Au molar ratios ranging from 15:1 to 2:1 were successfully synthesized based on a successive reduction strategy. The structure, morphology and composition of the as-prepared catalysts were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM (HR-TEM), energy dispersive spectrometer (EDS) line scan and the elemental mapping. The results show that the lattice orientations of the Pd nanocubes match those of the Au layers. Structural analysis establishes that the surface of the Au-decorated Pd nanocrystal shows its {111} faces. The heterogeneous nanocubes were used for ethanol electro-oxidation reaction in alkaline media. The electrochemical results indicate that the addition of Au to Pd can significantly improve the performance including catalytic activity, CO tolerance and stability. These results clearly suggest that the relative amounts of Au and Pd on the surface of the nanocubes are crucial for the improvement of Pd catalysis, and Pd5Au1 is identified as the most efficient catalyst since it possesses superior catalytic activity and long-term stability.
Co-reporter:Caiqin Wang, Huiwen Wang, Chunyang Zhai, Fangfang Ren, Mingshan Zhu, Ping Yang and Yukou Du
Journal of Materials Chemistry A 2015 - vol. 3(Issue 8) pp:NaN4398-4398
Publication Date(Web):2015/01/09
DOI:10.1039/C4TA05193A
A three-dimensional Au nanoparticle/reduced graphene oxide (RGO)/carbon fiber (CF) hybrid electrode (denoted as Au0.5/RGO/Au0.5/RGO/CF) was fabricated via a layer-by-layer method. The as-formed composite was characterized by Raman spectrometry, X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectrometry. Two RGO sheets and two Au nanoparticle sheets were assembled in alternate layers on the CFs. The catalytic performance of the as-prepared electrode was evaluated via cyclic voltammetry and chronopotentiometry. The as-synthesized three-dimensional Au0.5/RGO/Au0.5/RGO/CF electrode showed highly efficient electrocatalytic activity toward ethanol oxidation in alkaline medium and the Au nanoparticles were not affected by the graphene layers. The synergistic interaction between the RGO sheets and Au nanoparticles enhanced the catalytic activity of the electrode. The excellent electronic conductivity of the RGO sheets benefited electron transfer and the removal of the intermediate species by oxidation during the ethanol electrooxidation reaction, which improved the catalytic activity. As a result of the effects of these multiple factors, the Au0.5/RGO/Au0.5/RGO/CF electrode displayed a good catalytic performance.
Co-reporter:Duan Bin, Beibei Yang, Fangfang Ren, Ke Zhang, Ping Yang and Yukou Du
Journal of Materials Chemistry A 2015 - vol. 3(Issue 26) pp:NaN14006-14006
Publication Date(Web):2015/05/26
DOI:10.1039/C5TA02829A
This paper reports a simple method, in which Ni nanoparticles act as seeds for the formation of reduced graphene oxide (RGO) supported PdNi nanowire networks. The as-prepared catalysts were characterized by transmission electron microscopy (TEM), high-resolution TEM (HRTEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Electrochemical measurements proved that the PdNi-NNs/RGO catalyst has superior electrocatalytic activity towards the formic acid oxidation reaction with much larger electrochemically active surface area and mass activity as well as higher long term-stability in comparison with the Pd/RGO and commercial Pd/C catalysts. The optimized ratio of Pd and Ni is 1:1, tuned by simply adjusting the feed ratio of the precursors as well. It is proposed that the improvement of the catalytic performance is attributed to the special nanostructure and the synergistic effect between Pd and Ni. These findings highlight the facile synthesis of the PdNi nanowire networks on RGO sheets and their promising application as electrocatalysts for fuel cells.
Co-reporter:Fangfang Ren, Caiqin Wang, Chunyang Zhai, Fengxing Jiang, Ruirui Yue, Yukou Du, Ping Yang and Jingkun Xu
Journal of Materials Chemistry A 2013 - vol. 1(Issue 24) pp:NaN7261-7261
Publication Date(Web):2013/04/16
DOI:10.1039/C3TA11291H
In this paper, we report a facile, eco-friendly, one-pot method for the synthesis of a reduced graphene oxide (RGO) supported PtAuRu alloy nanoparticle catalyst (PtAuRu/RGO) by simultaneous reduction of H2PtCl6, HAuCl4, RuCl3 and graphene oxide (GO) using ethanol as the reduction agent. The as-formed PtAuRu/RGO catalyst has been characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and induced coupled plasma-atomic emission spectroscopy (ICP-AES). It is found that the PtAuRu nanoparticles formed alloy structures about 3.09 ± 0.73 nm in diameter and are evenly distributed on the RGO surface. The reduction degree of GO together with metal precursors is higher than that of only GO. Moreover, electrochemical measurements reveal that the electrocatalytic activity and stability of the PtAuRu/RGO catalyst for the methanol oxidation reaction are superior to those of PtAu/RGO, PtRu/RGO and Pt/RGO catalysts. These findings suggest that the prepared PtAuRu/RGO catalyst has great potential for use in direct methanol fuel cells (DMFCs).
Co-reporter:Beibei Yang, Jin Wang, Duan Bin, Mingshan Zhu, Ping Yang and Yukou Du
Journal of Materials Chemistry A 2015 - vol. 3(Issue 37) pp:NaN7448-7448
Publication Date(Web):2015/08/21
DOI:10.1039/C5TB01031D
An electrochemical sensor using a novel three dimensional (3D) ternary Pt nanodendrite/reduced graphene oxide/MnO2 nanoflower (Pt/RGO/MnO2) modified glassy carbon electrode was proposed for the selective and sensitive determination of dopamine (DA) in the presence of ascorbic acid (AA) and uric acid (UA). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to evaluate electrochemical behaviors of DA on the as-prepared electrode. The oxidation peak current of DA is linearly proportional to its concentration in the range from 1.5–215.56 μM, with a detection limit of 0.1 μM (at S/N = 3). Compared to bare RGO, Pt nanodendrite/RGO and MnO2 nanoflower modified electrodes, the 3D hierarchical ternary Pt/RGO/MnO2 composites displayed the highest electrocatalytic activity for the selective detection of DA. Moreover, the 3D Pt/RGO/MnO2 modified electrode can be reused with no obvious deterioration in the electrocatalytic performance. This work paves the way for developing a novel 3D nanostructure and offers new opportunities for improving the performance of electrochemical sensors with excellent sensitivity, repeatability and anti-interference.
Co-reporter:Zhangquan Yao, Mingshan Zhu, Fengxing Jiang, Yukou Du, Chuanyi Wang and Ping Yang
Journal of Materials Chemistry A 2012 - vol. 22(Issue 27) pp:NaN13713-13713
Publication Date(Web):2012/05/10
DOI:10.1039/C2JM31683H
In this paper, a facile electrochemical approach is developed towards synthesizing Pt nanoflowers modified reduced graphene oxide (RGO) wrapped carbon cloth (CC) as an anode (Pt nanoflowers/RGO/CCE) for formic acid and methanol electrooxidation. As revealed by SEM measurements, the carbon cloth is well wrapped by the RGO, and the RGO wrapped carbon cloth serves as an excellent support for electrochemically anchoring Pt nanoflowers, being more well-dispersed than without RGO. Compared with Pt nanoparticles/CCE, Pt nanoparticles/RGO/CCE, and Pt nanoflowers/CCE, the Pt nanoflowers/RGO/CCE displays a distinctly enhanced current density of CVs towards formic acid and methanol electrooxidation. The utilization of graphene results in well-dispersed Pt nanostructures with a uniform size and unique morphology structure; a relatively large surface area; and excellent electron or charge transfer rate, contributing to the enhanced electrocatalytic activity. The work likely opens up new promise for developing novel, low-cost yet highly efficient carbon material-based electrodes, especially for direct formic acid fuel cells and direct methanol fuel cells.
Co-reporter:Chunyang Zhai, Mingshan Zhu, Yongtao Lu, Fangfang Ren, Caiqin Wang, Yukou Du and Ping Yang
Physical Chemistry Chemical Physics 2014 - vol. 16(Issue 28) pp:NaN14807-14807
Publication Date(Web):2014/05/01
DOI:10.1039/C4CP01401D
In this paper, reduced graphene oxide modified highly ordered TiO2 nanotube arrays (RGO–TNTs) have been fabricated and used for photoelectrocatalytic (PEC) degradation of organic pollutants under visible light irradiation. Firstly, the RGO–TNT electrode was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman, FT-IR, X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance spectroscopy. The responsive photocurrent and electrochemical impedance spectroscopy (EIS) results indicated that our present RGO–TNTs displayed superior photoresponsive and electron transfer performances compared with bare TNTs. Moreover, by comparison with bare TNT electrode, the RGO–TNT arrays showed stable and evidently improved PEC activity for degradation of methyl orange (MO) under visible light illumination. This might be attributed to the introduction of RGO, which extended the absorption edge and promoted electron–hole separation in the PEC process. Furthermore, owing to the synergetic effect of photocatalysis and electrocatalysis in the PEC process, the efficiency of PEC process (3.0 × 10−3 min−1) is ca. 7.9 and 2.5 times faster than that of the electrochemical process (3.8 × 10−4 min−1) and photocatalytic process (1.2 × 10−3 min−1), respectively. Our investigation likely provides new opportunities for developing stable and efficient one-dimensional graphene modified TNT-based catalysts for PEC degradation of organic pollutants under visible light illumination.
Co-reporter:Hui Xu, Bo Yan, Jin Wang, Ke Zhang, Shumin Li, Zhiping Xiong, Caiqin Wang, Yukihide Shiraishi, Yukou Du and Ping Yang
Journal of Materials Chemistry A 2017 - vol. 5(Issue 30) pp:NaN15939-15939
Publication Date(Web):2017/07/17
DOI:10.1039/C7TA04598K
Shape-controlled synthesis of self-supported metallic nanocrystals with abundant active surface areas is of vital importance for the design and fabrication of novel outstandingly excellent electrocatalysts. Motivated by this, we herein report our research in the synthesis of self-supported porous 2D AuCu triangular nanoprisms via a facile wet-chemical method. Owing to the attractive 2D triangular structure, bifunctional and electronic effects between Au and Cu, such unique Au1Cu1 nanoprisms exhibited extremely high catalytic activities towards ethylene glycol and glycerol electrooxidation with mass activities of 2873 and 2263 mA mgAu−1, which are 3.0 and 3.9-fold enhancements over those of pure Au (958 and 573 mA mgAu−1), respectively. We trust this strategy may be extended to the syntheses of other multimetallic nanocatalysts with such fascinating nanostructures and the as-obtained porous triangular nanoprisms can be well applied to serve as highly desirable anode catalysts for electrooxidation of ethylene glycol and glycerol.
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