Meixian Li

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Name: 李美仙; Li, MeiXian

Organization: Peking University , China

Department: College of Chemistry and Molecular Engineering

Title: (PhD)

TOPICS

Analytical Chemistry

Chemicals
References

Study on the Electrochemistry of a Na3[Ti2P2O10F]·xH2O-Modified Glassy Carbon Electrode

Co-reporter:Xiaopei Miao;Guobao Li;Jingbo Hu;Zhiwei Zhu;Yuanhua Shao

The Journal of Physical Chemistry C March 19, 2009 Volume 113(Issue 11) pp:4592-4596

Publication Date(Web):2017-2-22

DOI:10.1021/jp8103672

A new oxyfluorinated titanium phosphate Na3[Ti2P2O10F]·xH2O (TiP)-modified electrode was prepared by casting the dispersion of TiP on a glassy carbon electrode. The electrochemical behavior of the modified electrode was investigated by cyclic voltammetry, and a couple of reduction/reoxidation peaks corresponding to the reduction of Ti (IV) were found at −1.29 V versus SCE in the 0.1 M NaCl solution, which was supported by UV−vis and FTIR characterization. The modified electrode showed electrocatalysis toward the reduction of H2O2. Furthermore, the addition of phosphate in the supporting electrolyte resulted in an easier reduction of Ti(IV) and direct electron transfer of cytochrome c at the modified electrode due to changes in the surface structure of the TiP films. The results indicate that TiP can act as not only a good electron-transfer mediator but also an electron-transfer promoter.

Electrodeposited Mo3S13 Films from (NH4)2Mo3S13·2H2O for Electrocatalysis of Hydrogen Evolution Reaction

Co-reporter:Kuangzhou Du, Lirong Zheng, Tanyuan Wang, Junqiao Zhuo, Zhiwei Zhu, Yuanhua Shao, and Meixian Li

ACS Applied Materials & Interfaces June 7, 2017 Volume 9(Issue 22) pp:18675-18675

Publication Date(Web):May 19, 2017

DOI:10.1021/acsami.7b01333

Molybdenum sulfides are considered to be one kind of the promising candidates as cheap and efficient electrocatalysts for hydrogen evolution reaction (HER). But this is still a gap on electrocatalytic performance toward Pt. To further enhance electrocatalytic activity of molybdenum sulfides, in this work, we prepared Mo3S13 films with high ratio of sulfur to molybdenum by electrodeposition. The Mo3S13 films exhibit highly efficient electrocatalytic activity for HER and achieve a current density of 10 mA/cm2 at an overpotential of 200 mV with an onset potential of 130 mV vs RHE and a Tafel slope of 37 mV/dec, which is superior to other reported MoS2 films. The highly electrocatalytic activity is attributed to high percentage of bridging S22– and apical S2– as well as good conductivity. This study provides an avenue for designing new molybdenum sulfides electrocatalysts.Keywords: electrocatalysis; electrodeposition; hydrogen evolution reaction; Mo3S13; molybdenum sulfides;

One-step electroreductively deposited iron-cobalt composite films as efficient bifunctional electrocatalysts for overall water splitting

Co-reporter:Wanglian Liu, Kuangzhou Du, Lu Liu, Jinxuan Zhang, Zhiwei Zhu, Yuanhua Shao, Meixian Li

Nano Energy 2017 Volume 38(Volume 38) pp:

Publication Date(Web):1 August 2017

DOI:10.1016/j.nanoen.2016.11.047

•Electroreductive deposition of Fe-Co composite films on carbon fiber papers.•The films were prepared in a solution containing Fe3+ and Co2+ with and without N2.•The films show highly efficient electrocatalytic performance for OER and HER.•The films can be used as bifunctional catalysts for water splitting.Due to the large overpotentials on both cathodic hydrogen evolution reaction (HER) and anodic oxygen evolution reaction (OER) during the process of water splitting, the large-scale production of hydrogen is limited. Therefore, it is crucial to find earth-abundant, low-cost and efficient bifunctional catalysts for such process. In this paper, we report one-step electroreductive deposition of Fe-Co composite films on carbon fiber papers (CFPs) in a solution containing Fe(III) and Co(II) ions without and with N2 bubbling, and the prepared composite films show highly efficient electrocatalytic performances and good durabilities for both OER and HER in 1.0 M KOH. To reach a current density of 10 mA cm−2, the overpotentials are only 283 mV for OER and −163 mV for HER with small Tafel slopes of 34 and 51 mV dec−1, respectively. Moreover, the Fe-Co composite films can be used as bifunctional catalysts for water splitting with the current density of 10 mA cm−2 at 1.68 V, which is comparable with most of the Ni-based films reported. This proves that the Ni-free derivatives of 3d transition metals can also show high catalytic performance.Download high-res image (445KB)Download full-size image

The effects of exfoliation, organic solvents and anodic activation on the catalytic hydrogen evolution reaction of tungsten disulfide

Co-reporter:Wanglian Liu;John Benson;Craig Dawson;Andrew Strudwick;Arun Prakash Aranga Raju;Yisong Han;Pagona Papakonstantinou

Nanoscale (2009-Present) 2017 vol. 9(Issue 36) pp:13515-13526

Publication Date(Web):2017/09/21

DOI:10.1039/C7NR04790H

The rational design of transition metal dichalcogenide electrocatalysts for efficiently catalyzing the hydrogen evolution reaction (HER) is believed to lead to the generation of a renewable energy carrier. To this end, our work has made three main contributions. At first, we have demonstrated that exfoliation via ionic liquid assisted grinding combined with gradient centrifugation is an efficient method to exfoliate bulk WS2 to nanosheets with a thickness of a few atomic layers and lateral size dimensions in the range of 100 nm to 2 nm. These WS2 nanosheets decorated with scattered nanodots exhibited highly enhanced catalytic performance for HER with an onset potential of −130 mV vs. RHE, an overpotential of 337 mV at 10 mA cm−2 and a Tafel slope of 80 mV dec−1 in 0.5 M H2SO4. Secondly, we found a strong aging effect on the electrocatalytic performance of WS2 stored in high boiling point organic solvents such as dimethylformamide (DMF). Importantly, the HER ability could be recovered by removing the organic (DMF) residues, which obstructed the electron transport, with acetone. Thirdly, we established that the HER performance of WS2 nanosheets/nanodots could be significantly enhanced by activating the electrode surface at a positive voltage for a very short time (60 s), decreasing the kinetic overpotential by more than 80 mV at 10 mA cm−2. The performance enhancement was found to arise primarily from the ability of a formed proton-intercalated amorphous tungsten trioxide (a-WO3) to provide additional active sites and favourably modify the immediate chemical environment of the WS2 catalyst, rendering it more favorable for local proton delivery and/or transport to the active edge site of WS2. Our results provide new insights into the effects of organic solvents and electrochemical activation on the catalytic performance of two-dimensional WS2 for HER.

Molybdenum disulfide and Au ultrasmall nanohybrids as highly active electrocatalysts for hydrogen evolution reaction

Co-reporter:Jinxuan Zhang;Tanyuan Wang;Lu Liu;Kuangzhou Du;Wanglian Liu;Zhiwei Zhu

Journal of Materials Chemistry A 2017 vol. 5(Issue 8) pp:4122-4128

Publication Date(Web):2017/02/21

DOI:10.1039/C6TA10385E

Molybdenum disulfide (MoS2) is a promising catalyst for hydrogen generation from water splitting. However, there is still a gap compared to electrocatalytic performance of Pt group metals. Herein, we propose a simple solvothermal method to prepare ultrasmall MoS2–Au nanohybrids with average diameters of 2.5 nm. The MoS2–Au nanohybrids exhibit superior HER performance with a low onset potential of 17 mV, a Tafel slope of 40 mV dec−1 and a current density of 10 mA cm−2 at an overpotential of only 66 mV. The enhanced HER catalytic activity is attributed to the doping of gold resulting in a synergistic effect between Au and MoS2, which promotes the activity of the edge sites and enhancement of conductivity. Our work has provided a new approach to synthesize hybridized MoS2 for an enhanced hydrogen evolution reaction (HER).

Highly Catalytic Nanodots with Renal Clearance for Radiation Protection

Co-reporter:Xiao-Dong Zhang, Jinxuan Zhang, Junying Wang, Jiang Yang, Jie Chen, Xiu Shen, Jiao Deng, Dehui Deng, Wei Long, Yuan-Ming Sun, Changlong Liu, and Meixian Li

ACS Nano 2016 Volume 10(Issue 4) pp:4511

Publication Date(Web):March 27, 2016

DOI:10.1021/acsnano.6b00321

Ionizing radiation (gamma and X-ray) is widely used in industry and medicine, but it can also pose a significant hazardous effect on health and induce cancer, physical deformity, and even death, due to DNA damage and invasion of free radicals. There is therefore an urgent unmet demand in designing highly efficient radioprotectants with synergetic integration of effective renal clearance and low toxicity. In this study, we designed ultrasmall (sub-5 nm) highly catalytically active and cysteine-protected MoS2 dots as radioprotectants and investigated their application in protection against ionizing radiation. In vivo preclinical studies showed that the surviving fraction of MoS2-treated mice can appreciably increase to up to 79% when they were exposed to high-energy ionizing radiation. Furthermore, MoS2 dots can contribute in cleaning up the accumulated free radicals within the body, repairing DNA damage, and recovering all vital chemical and biochemical indicators, suggesting their unique role as free radical scavengers. MoS2 dots showed rapid and efficient urinary excretion with more than 80% injected dose eliminated from the body after 24 h due to their ultrasmall hydrodynamic size and did not cause any noticeable toxic responses up to 30 days.Keywords: MoS2 dots; radiation; radioprotectants

High-Performance Electrocatalysis for Hydrogen Evolution Reaction Using Se-Doped Pyrite-Phase Nickel Diphosphide Nanostructures

Co-reporter:Junqiao Zhuo, Miguel Cabán-Acevedo, Hanfeng Liang, Leith Samad, Qi Ding, Yongping Fu, Meixian Li, and Song Jin

ACS Catalysis 2015 Volume 5(Issue 11) pp:6355

Publication Date(Web):September 16, 2015

DOI:10.1021/acscatal.5b01657

The study of efficient, robust, and earth-abundant electrocatalysts for the hydrogen evolution reaction (HER) is essential for hydrogen-based energy technologies. Previous works have demonstrated that pyrite-structure materials (e.g., CoS2, NiSe2) are efficient HER catalysts. Here, we first systematically investigate the nanostructure synthesis of a series of pyrite-phase nickel phosphoselenide materials—NiP2, Se-doped NiP2 (NiP1.93Se0.07), P-doped NiSe2 (NiP0.09Se1.91), and NiSe2—through a facile thermal conversion of Ni(OH)2 nanoflakes. The similar nanostructures enable a systematic and fair comparison of their structural properties and catalytic activities for HER. We found that NiP1.93Se0.07 shows the best HER performance, followed by NiP2, NiP0.09Se1.91, and NiSe2. Se-doped NiP2 grown on carbon fiber paper can achieve an electrocatalytic current density of 10 mA cm–2 at an overpotential as low as 84 mV and a small Tafel slope of 41 mV decade–1. This study not only estabilishes Se-doped NiP2 as a competitive HER catalyst, but also demonstrates that doping or alloying of developed catalysts (especially doping with anions from another group; e.g., selenium to phosphorus) can improve the HER catalytic activity, which provides a general strategy to improve catalytic efficiencies of existing electrocatalysts for HER.Keywords: doping; electrocatalysis; hydrogen evolution reaction (HER); nickel diphosphide (NiP2); nickel diselenide (NiSe2); pyrite phase

Enhanced electrocatalytic activity of MoP microparticles for hydrogen evolution by grinding and electrochemical activation

Co-reporter:Tanyuan Wang, Kuangzhou Du, Wanglian Liu, Zhiwei Zhu, Yuanhua Shao and Meixian Li

Journal of Materials Chemistry A 2015 vol. 3(Issue 8) pp:4368-4373

Publication Date(Web):22 Jan 2015

DOI:10.1039/C4TA06651K

Transition metal phosphides like CoP, MoP, Ni2P are suggested to be highly efficient catalysts for hydrogen evolution reaction (HER). However, HER-inert oxides would usually form on the surfaces of these phosphides during preparation and long-term storage. In this study, a simple combination method of grinding and electrochemical activation is used to tune the surface states of long-term stored commercial MoP microparticles, which show low activity for HER due to the molybdenum and phosphorus oxides on the surface, resulting in more exposed active sites of MoP and an enhanced catalytic activity for HER with an onset potential of 0.08 V vs. RHE and a Tafel slope of 50 mV dec−1.

Electrochemically Fabricated Polypyrrole and MoSx Copolymer Films as a Highly Active Hydrogen Evolution Electrocatalyst

Co-reporter:Tanyuan Wang;Junqiao Zhuo;Kuangzhou Du;Bingbo Chen;Zhiwei Zhu;Yuanhua Shao

Advanced Materials 2014 Volume 26( Issue 22) pp:3761-3766

Publication Date(Web):

DOI:10.1002/adma.201400265

Direct Detection of DNA below ppb Level Based on Thionin-Functionalized Layered MoS2 Electrochemical Sensors

Co-reporter:Tanyuan Wang, Ruizhi Zhu, Junqiao Zhuo, Zhiwei Zhu, Yuanhua Shao, and Meixian Li

Analytical Chemistry 2014 Volume 86(Issue 24) pp:12064

Publication Date(Web):November 13, 2014

DOI:10.1021/ac5027786

A layered MoS2–thionin composite was prepared by sonicating their mixture in an ionic liquid and gradient centrifugation. Because DNA is rarely present in single-stranded form, either naturally or after PCR amplification, the composite was used for fabrication of a double-stranded DNA (dsDNA) electrochemical biosensor due to stable electrochemical response, intercalation, and electrostatic interaction of thionin with DNA. The linear range over dsDNA concentration from 0.09 ng mL–1 to 1.9 ng mL–1 is obtained, and moreover, it is suitable for the detection of single-stranded DNA (ssDNA). The biosensor has been applied to the detection of circulating DNA from healthy human serum, and satisfactory results have been obtained. The constructed DNA electrochemical biosensor shows potential application in the fields of bioanalysis and clinic diagnosis. Furthermore, this work proposes a new method to construct electrochemical biosensors based on MoS2 sheets.

Synergistic Catalytic Effect of MoS2 Nanoparticles Supported on Gold Nanoparticle Films for a Highly Efficient Oxygen Reduction Reaction

Co-reporter:Tanyuan Wang;Junqiao Zhuo;Ye Chen;Kuangzhou Du; Pagona Papakonstantinou; Zhiwei Zhu; Yuanhua Shao; Meixian Li

ChemCatChem 2014 Volume 6( Issue 7) pp:1877-1881

Publication Date(Web):

DOI:10.1002/cctc.201402038

Abstract

MoS₂ nanoparticles supported on gold nanoparticle films (AuNP/MoS₂ films) were constructed by a simple two-step drop-casting modification process on a glassy carbon electrode. The films realized a direct four-electron pathway for the oxygen reduction reaction (ORR) in alkaline media with an onset potential of −0.10 V versus the saturated calomel electrode. The films exhibited superior stability and better electrocatalytic performance than commercial Pt/C. Electrochemical studies and composition characterization illustrated that the enhanced catalytic activity of the AuNP/MoS₂ films could be attributed to the synergistic effect of the positive onset potential of the gold nanoparticles for the ORR and the four-electron oxygen reduction properties of the ultrasmall MoS₂ nanoparticles, which is different from gold nanoparticle and MoS₂ nanoparticle modified electrodes.

Enhanced electrocatalytic activity for hydrogen evolution reaction from self-assembled monodispersed molybdenum sulfide nanoparticles on an Au electrode

Co-reporter:Tanyuan Wang, Lu Liu, Zhiwei Zhu, Pagona Papakonstantinou, Jingbo Hu, Hongyun Liu and Meixian Li

Energy & Environmental Science 2013 vol. 6(Issue 2) pp:625-633

Publication Date(Web):21 Nov 2012

DOI:10.1039/C2EE23513G

Ultrasmall molybdenum sulfide nanoparticles with diameters of 1.47 ± 0.16 nm were fabricated from bulk MoS2 by a combination of ultrasonication and centrifugation. The nanoparticles were then assembled on an Au surface to form a film with high electrocatalytic activity for hydrogen evolution reaction (HER). A Tafel slope of 69 mV per decade was measured for this film and the onset potential was estimated to be −0.09 V. The small loading (1.03 μg cm−2) and the high current density (0.92 mA cm−2 at η = 0.15 V) demonstrated extremely high catalytic efficiency. X-ray photoelectron spectroscopic results revealed that the assembled nanoparticle film was sulfur enriched with abundant S edges and a structural rearrangement of the S rich particles might occur during the self-assembly process, resulting in significantly enhanced electrocatalytic activity for HER. Electrochemical impedance measurements suggested that the assembling process optimized the conductivity of the nanoparticle film, which contributed to the enhanced HER catalytic activity. Our research has provided a new way to synthesize active molybdenum sulfide nanoparticles for HER and a new approach to achieve enrichment of S edges on molybdenum sulfide, which might have potential use not only for electrocatalytic HER, but also for photoelectrocatalytic HER and plasmon-enhanced water splitting.

Salts of C60(OH)8 Electrodeposited onto a Glassy Carbon Electrode: Surprising Catalytic Performance in the Hydrogen Evolution Reaction

Co-reporter:Junqiao Zhuo;Tanyuan Wang;Gang Zhang;Lu Liu; Liangbing Gan; Meixian Li

Angewandte Chemie International Edition 2013 Volume 52( Issue 41) pp:10867-10870

Publication Date(Web):

DOI:10.1002/anie.201305328

Size-Dependent Enhancement of Electrocatalytic Oxygen-Reduction and Hydrogen-Evolution Performance of MoS2 Particles

Co-reporter:Tanyuan Wang;Dongliang Gao;Junqiao Zhuo; Zhiwei Zhu; Pagona Papakonstantinou; Yan Li; Meixian Li

Chemistry - A European Journal 2013 Volume 19( Issue 36) pp:11939-11948

Publication Date(Web):

DOI:10.1002/chem.201301406

Abstract

MoS₂ particles with different size distributions were prepared by simple ultrasonication of bulk MoS₂ followed by gradient centrifugation. Relative to the inert microscale MoS₂, nanoscale MoS₂ showed significantly improved catalytic activity toward the oxygen-reduction reaction (ORR) and hydrogen-evolution reaction (HER). The decrease in particle size was accompanied by an increase in catalytic activity. Particles with a size of around 2 nm exhibited the best dual ORR and HER performance with a four-electron ORR process and an HER onset potential of −0.16 V versus the standard hydrogen electrode (SHE). This is the first investigation on the size-dependent effect of the ORR activity of MoS₂, and a four-electron transfer route was found. The exposed abundant Mo edges of the MoS₂ nanoparticles were proven to be responsible for the high ORR catalytic activity, whereas the origin of the improved HER activity of the nanoparticles was attributed to the plentiful exposed S edges. This newly discovered process provides a simple protocol to produce inexpensive highly active MoS₂ catalysts that could easily be scaled up. Hence, it opens up possibilities for wide applications of MoS₂ nanoparticles in the fields of energy conversion and storage.

Amplified optical transduction of proteins derived from Mo6S9−xIx nanowires

Co-reporter:Nijuan Sun, Martin McMullan, Pagona Papakonstantinou, Dragan Mihailovic, Meixian Li

Progress in Natural Science: Materials International 2013 Volume 23(Issue 3) pp:326-330

Publication Date(Web):June 2013

DOI:10.1016/j.pnsc.2013.04.002

We demonstrate that Mo6S9−xIx nanowires (MoSI NWs) enable the detection of proteins with cytochrome c as a model protein using UV–vis spectrometry. The association of cytochrome c with the nanowires was verified by scanning electroctron microscopy, X-ray photoelectron, light scattering and micro-FTIR spectroscopies. Our results show that MoSI NWs is a promising nanostructure material for the development of ultrasensitive sensors for detecting proteins. The new MoSI NW derived amplification bioassay is expected to provide a straightforward and effective strategy for protein analysis and biosensor construction.

Electrochemistry of double-wall carbon nanotubes encapsulating C60 and their spectral characterization

Co-reporter:Kaiye Wu, Hanxun Qiu, Jingbo Hu, Nijuan Sun, Zhiwei Zhu, Meixian Li, Zujin Shi

Carbon 2012 Volume 50(Issue 12) pp:4401-4408

Publication Date(Web):October 2012

DOI:10.1016/j.carbon.2012.05.016

Electrochemistry of double-wall carbon nanotubes (DWCNTs) encapsulating C60 (C60@DWCNT) have been studied by preparing a C60@DWCNT modified electrode, and three pairs of reversible electro-reduction waves corresponding to electron transfer reactions of C60 inside DWCNTs have been obtained in a mixed solvent of toluene and acetonitrile (4:1, v:v) containing tetrabutylammonium cation as supporting electrolyte, which indicates that DWCNTs act as molecular wires to allow electrical communication between the underlying electrode and the redox-active guest C60. The influencing factors on the electrochemistry of C60@DWCNT modified electrodes have been investigated. The results suggest that the voltammetric behavior of C60@DWCNT is dependent on the nature of the supporting electrolyte and the solvent system. In addition, spectral characterization of the C60@DWCNT modified electrodes before and after electrochemical scanning reveals interaction between C60 and DWCNT and verifies the reduction of C60 encapsulated in DWCNTs. C60 molecules inside DWCNTs retains their redox activity, and can also act as an electron-transfer mediator to electrocatalyze the reduction of halohydrocarbon.

Aptamer conjugated Mo6S9−xIx nanowires for direct and highly sensitive electrochemical sensing of thrombin

Co-reporter:Martin McMullan, Nijuan Sun, Pagona Papakonstantinou, Meixian Li, Wuzong Zhou, Dragan Mihailovic

Biosensors and Bioelectronics 2011 Volume 26(Issue 5) pp:1853-1859

Publication Date(Web):15 January 2011

DOI:10.1016/j.bios.2010.01.030

We demonstrate the use of a novel electrochemical sensing platform based on aptamer conjugated Mo6S9−xIx nanowires (MoSI NWs) for the highly sensitive detection of the blood clotting enzyme thrombin. MoSI NWs nanowires were self-assembled on a gold electrode to which thrombin binding aptamers were covalently attached. The modification and immobilization steps of the electrodes were characterised by cyclic voltammetry along with high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. The platform is based on the creation of a self-assembled MoSI MW layer via the sulfur–gold affinity followed by the creation of MoSI-thiolated aptamer conjugates via the sulfur–sulfur affinity. Using this system, sensitive quantitative detection of thrombin is realized by monitoring differences of differential pulse voltammetric responses of electrostatically trapped [Ru(NH3)6]3+ cations to the aptamer before and after thrombin binding. The sensitivity limit for the detection of thrombin is 10 pM. This value is 10-fold better than all currently reported one step label free electrochemical strategies. Given the direct label free nature of the approach and the simplicity of the electronic detection, the aptamer conjugated MoSI NWs biosensor appears well suited for implementation in portable point of care microdevices directed at the rapid and sensitive detection of proteins and pathogens.

Thionin attached to a gold electrode modified with self-assembly of Mo6S9−XIX nanowires for amplified electrochemical detection of natural DNA

Co-reporter:Hong Lin, Huiming Cheng, Lu Liu, Zhiwei Zhu, Yuanhua Shao, Pagona Papakonstantinou, Dragan Mihailovič, Meixian Li

Biosensors and Bioelectronics 2011 Volume 26(Issue 5) pp:1866-1870

Publication Date(Web):15 January 2011

DOI:10.1016/j.bios.2010.01.035

We demonstrate a novel electrochemical sensor for highly sensitive detection of natural double-stranded deoxyribonucleic acid (dsDNA) based on thionin (Th) attached to Mo6S9−XIX nanowires (MoSI NWs) self-assembled on a gold electrode. The sensing detection is based on a decrease of the voltammetric response of the immobilized Th due to the binding of Th with dsDNA through intercalation. MoSI NWs act as molecular connectors to provide an amplification and conductive sensing platform for the electrochemical detection of dsDNA, because many sulfur atoms at the ends and sides of MoSI NWs permit covalent bonds to be formed with gold as well as MoSI NWs with negative charges allow electrostatic binding with Th. A determination limit of 0.62 ng/mL for dsDNA with this novel sensor is achieved, which is three orders of magnitude lower than that in the absence of MoSI NWs. The operation is simple and label-free.

Electrochemistry of a C84-C2(IV)-Modified Electrode in Aqueous Solutions and Its Interaction with Guanine

Co-reporter:Lu Liu ; Shukuan Wang ; Zhiwei Zhu ; Meixian Li ;Baoyun Sun

The Journal of Physical Chemistry C 2011 Volume 115(Issue 13) pp:5966-5973

Publication Date(Web):March 7, 2011

DOI:10.1021/jp112033c

The electrochemistry of C84 isomer-modified electrodes was investigated in aqueous solutions. It is found that the C84-C2(IV) (denoted as C2(IV) for short)-modified electrode shows one pair of redox peaks, and its electrochemical responses depend on the nature of cations of the supporting electrolyte. Scanning electron microscopy, X-ray photoelectron spectroscopy (XPS), and ultraviolet−visible-near-infrared (UV−vis-NIR) spectral characterizations reveal that the pair of redox peaks originate from one-electron-transfer reduction and reoxidation of C2(IV) in the aqueous solution. Furthermore, interaction between C2(IV) and guanine has been investigated by electrochemistry, XPS, and UV−vis-NIR, and the results illustrate that C2(IV) and guanine have formed a charge-transfer complex.

Electrochemical synthesis of a ferrocenecarboxylic acid–C60 composite and its electrocatalysis to hydrogen peroxide

Co-reporter:Xiaopei Miao, Lu Liu, Shukuan Wang, Hong Lin, Baoyun Sun, Jingbo Hu, Meixian Li

Electrochemistry Communications 2010 Volume 12(Issue 1) pp:90-93

Publication Date(Web):January 2010

DOI:10.1016/j.elecom.2009.10.043

A new ferrocenecarboxylic acid–C60 composite (Fc–C60) has been synthesized by controlled potential electrolysis. A composite modified glassy carbon electrode has been prepared based on its good electrochemical activity. The modified electrode in 0.1 M NaClO4 solution shows a reversible oxidation wave at E1/2 = 0.32 V (vs. SCE) attributed to the oxidation of the ferrocene entity and a quasi-reversible reduction wave of C60 entity at E1/2 = −0.54 V (vs. SCE). Electrocatalytic studies show that Fc–C60 at the modified electrode can mediate the reduction of hydrogen peroxide (H2O2), and a broad linear range from 1.2 μM to 21.9 mM for H2O2 were obtained with a determination limit of 2.5 × 10−7 M by amperometry.

Electrochemistry of symmetrical fullerene dimer C121 film modified electrodes

Co-reporter:Xiaopei Miao, Tongxiang Ren, Nijuan Sun, Jingbo Hu, Zhiwei Zhu, Yuanhua Shao, Baoyun Sun, Yuliang Zhao, Meixian Li

Journal of Electroanalytical Chemistry 2009 Volume 629(1–2) pp:152-157

Publication Date(Web):15 April 2009

DOI:10.1016/j.jelechem.2009.02.008

C121 and C121/didodecyldimethylammonium bromide (DDAB) film modified electrodes have been constructed and their electrochemistry has been studied. In the acetonitrile solution containing 0.1 M tetrabutylammonium perchlorate, the C121 films show three couples of relatively stable redox peaks corresponding to three two-electron transfer processes involving reduction of two fullerene units in the dimers. In an aqueous solution containing 0.1 M tetrabutylammonium bromide, the C121 films display an irreversible reduction peak, whereas the C121/DDAB films display two couples of quasi-reversible redox peaks with the splitting first peak, and the C121/DDAB films have good reversibility and stability in the aqueous solution due to existence of DDAB. All of these experimental results indicate that voltammetric behaviors of the C121 films are different from those of C60 films due to different structures though C121 is carbon-bridged C60 dimer, and the common characteristics are that their electrochemical behaviors are dependent on the nature of solvent and cation of supporting electrolyte. Furthermore, electrocatalysis of H2O2 at the C121/DDAB films was explored in the aqueous solution, which indicates that C121 is a good electron-transfer mediator.

Bioassembled Nanocircuits of Mo6S9−xIx Nanowires for Electrochemical Immunodetection of Estrone Hapten

Co-reporter:Nijuan Sun, Martin McMullan, Pagona Papakonstantinou, Hui Gao, Xinxiang Zhang, Dragan Mihailovic and Meixian Li

Analytical Chemistry 2008 Volume 80(Issue 10) pp:3593

Publication Date(Web):April 12, 2008

DOI:10.1021/ac7024893

We demonstrate a novel and highly sensitive electrochemical detection of estrone based on an immunosensor platform, composed of bioassembled nanocircuits of Mo6S9−xIx nanowires (MoSI NWs) covalently connected to anti-estrone antibodies. The one-step, label-free, and quantitative detection of estrone is realized by employing the [Ru(NH3)6]3+/2+ redox ions to sense anti-estrone antibody and estrone interactions. The MoSI NWs/anti-estrone antibody nanocircuit architectures provide an amplification and conductive pathway for the specific electrochemical sensing of estrone hapten. A detection limit of 1.4 pg·mL−1 was achieved in contrast to previous electrochemical techniques in which the sensitivity was limited to the nanomolar range.

Molybdenum disulfide and Au ultrasmall nanohybrids as highly active electrocatalysts for hydrogen evolution reaction

Co-reporter:Jinxuan Zhang, Tanyuan Wang, Lu Liu, Kuangzhou Du, Wanglian Liu, Zhiwei Zhu and Meixian Li

Journal of Materials Chemistry A 2017 - vol. 5(Issue 8) pp:NaN4128-4128

Publication Date(Web):2017/02/02

DOI:10.1039/C6TA10385E

Enhanced electrocatalytic activity of MoP microparticles for hydrogen evolution by grinding and electrochemical activation

Co-reporter:Tanyuan Wang, Kuangzhou Du, Wanglian Liu, Zhiwei Zhu, Yuanhua Shao and Meixian Li

Journal of Materials Chemistry A 2015 - vol. 3(Issue 8) pp:NaN4373-4373

Publication Date(Web):2015/01/22

DOI:10.1039/C4TA06651K