Co-reporter:Weihua Feng, Jianzhang Fang, Lanxin Zhang, Shaoyou Lu, Shuxing Wu, Cong Cheng, Yi Chen, Yu Ling, Zhanqiang Fang
Materials Research Bulletin 2017 Volume 94(Volume 94) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.materresbull.2017.05.042
•Bi metal was deposited on the surface of Bi12SiO20 by a solvothermal method under a relatively low temperature.•Bi/BSO exhibited highly enhanced photocatalytic activity as compared to Bi12SiO20.•Its improvements resulted from the SPR effect induced by Bi metal and the unique features of oxygen vacancies.•Oxygen vacancies also promote the generation of radicals by the absorption of small molecules.•h+ and OH were the main reactive species of Bi/BSO in the photocatalysis.Metallic Bi coupled Bi12SiO20 (Bi/BSO) is synthesized by a solvothermal method. Characterization demonstrates the presence of Bi metal on Bi12SiO20, the intimate interface between Bi metal and Bi12SiO20, and the existence of oxygen vacancies in Bi/BSO. It possesses improved photocatalytic activity, and its reaction rates are 23 and 1.4 times higher than those of Bi12SiO20 in RhB and 2,4-DCP removal. Its enhanced photocatalytic activity is attributed to its enhanced visible-light-response and improved charge separation resulting from the surface plasmon resonance effect endowed by metallic Bi and the unique features of oxygen vacancies on Bi12SiO20. Meanwhile, with the addition of H2O2, its reaction rates are 3 times higher than that of Bi12SiO20 in 2, 4-DCP removal, indicating that oxygen vacancies are beneficial for the generation of OH. This work paves a new way to enhance the photocatalytic activity of Bi12SiO20 by utilizing the cost-effective plasmonic Bi metal and oxygen vacancies.Download high-res image (113KB)Download full-size image
Co-reporter:Dongdong Chen, Jianzhang Fang, Shaoyou Lu, GuangYing Zhou, Weihua Feng, Fan Yang, Yi Chen, ZhanQiang Fang
Applied Surface Science 2017 Volume 426(Volume 426) pp:
Publication Date(Web):31 December 2017
DOI:10.1016/j.apsusc.2017.07.139
•Bi modified Bi2S3 pillared g-C3N4 photocatalyst (BBC) is successfully developed in a mixed solvothermal environment.•The possible reaction mechanisms for g-C3N4/Bi2S3 and the novel photocatalyst BBC are proposed.•BBC exhibits higher photocatalytic reduction and oxidation performance than g-C3N4/Bi2S3 and pure g-C3N4.•Improved charge separation is responsible for the enhanced photocatalytic performance.•. The photocatalytic mechanism of BBC is tentatively proposed.A novel efficient Bi modified Bi2S3 pillared g-C3N4 (BBC) plasmonic semiconductor photocatalyst has been successfully developed in a mixed solvothermal environment. The photocatalytic abilities of the as-prepared samples are examined by the photocatalytic reduction of Cr(VI) and oxidation of tetracycline (TC). And the chemical composition, structure, morphology and photo-absorption properties of the photocatalysts have been investigated by XRD, FT-IR, XPS, TEM, HRTEM and DRS methods, respectively. It is found that the addition of triethanolamine (TEA) results in the formation of the pillared-g-C3N4 (PG) nanostructure. The agglomeration of g-C3N4 nanosheets moiety and Bi2S3 nanorods moiety can be both hindered effectively by the special PG structure. And the photocatalytic results indicate that BBC exhibits the best photoreduction and photooxidation performances among all the samples, and meanwhile possesses superior photo-stability during the recycling runs. The enhanced photocatalytic activity of BBC could be ascribed to the furtherance of charge separation, localized surface plasma resonance (SPR) effect of metallic Bi and the excellent reaction interface. Finally, a tentative mechanism of BBC for photocatalytic reduction of Cr(VI) and oxidation of TC is discussed in detail.Download high-res image (151KB)Download full-size image
Co-reporter:Yi Chen, Jianzhang Fang, Shaoyou Lu, Chaoping Cen, Cong Cheng, Lu Ren, Weihua Feng and Zhanqiang Fang
RSC Advances 2016 vol. 6(Issue 19) pp:15745-15752
Publication Date(Web):28 Jan 2016
DOI:10.1039/C5RA25792A
Visible-light-activated (Ba,Mg)-codoped Bi12GeO20 has been successfully synthesized through a one-step hydrothermal method. The as-prepared samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectra (DRS) and photoluminescence spectroscopy (PL). XPS study suggests that barium and magnesium were introduced into the Bi12GeO20 crystal successfully. The band gap of (Ba,Mg)-codoped Bi12GeO20 was greatly reduced in comparison with the pure and single-doped Bi12GeO20. (Ba,Mg)-codoped Bi12GeO20 showed higher photocatalytic activity than pure Bi12GeO20 and single-doped Bi12GeO20 in the photodegradation of Rhodamine B (RhB) aqueous solution under visible light irradiation. Photogenerated holes were the dominating active species, with the secondary and minor factors of hydroxyl radical and superoxide radical in the photodegradation process of (Ba,Mg)-codoped Bi12GeO20. For three cycles, the co-doped Bi12GeO20 exhibited high stability.
Co-reporter:Yunfang Chen;Shaoyou Lu;Weicheng Xu;Zhang Liu;Xiaoxin Xu;Zhanqiang Fang
Journal of Chemical Technology and Biotechnology 2015 Volume 90( Issue 5) pp:947-954
Publication Date(Web):
DOI:10.1002/jctb.4407
Abstract
BACKGROUND
Chlorophenols (CPs) are organic pollutants and are most widespread in the aqueous environment. Photocatalytic degradation of organic compounds has been extensively studied as a potential technology for water treatment. In this study, BiOI/Bi2WO6 hierarchical heterostructure with flower-like morphology was synthesized by a facile method using a one-step hydrothermal approach. The catalytic activities of the photocatalysts were tested by the degradation of 2,4-DCP under visible-light irradiation and the photocatalysis mechanism of BiOI/Bi2WO6 was investigated.
RESULTS
The as-prepared catalysts exhibited the characteristic peaks of BiOI and Bi2WO6. The photocatalytic activities, which were evaluated by degradation of 2,4-DCP under visible light irradiation, were enhanced significantly by BiOI/Bi2WO6 hierarchical heterostructures with different molar ratios of BiOI to Bi2WO6.
CONCLUSIONS
BiOI/Bi2WO6 hierarchical heterostructure significantly enhanced the photocatalytic activity. The optimum percentage of BiOI was 10%. The optimal initial pH value of 2,4-DCP was determined to be pH 8. The possible reaction mechanisms were discussed on the basis of the calculated energy band positions. © 2014 Society of Chemical Industry
Co-reporter:Weicheng Xu, Jianzhang Fang, Yunfang Chen, Shaoyou Lu, Guangying Zhou, Ximiao Zhu, Zhanqiang Fang
Materials Chemistry and Physics 2015 Volume 154() pp:30-37
Publication Date(Web):15 March 2015
DOI:10.1016/j.matchemphys.2015.01.040
•A novel Bi2S3/Bi2Sn2O7 heterostructure was prepared by hydrothermal method.•The Bi2S3/Bi2Sn2O7 materials showed high photocatalytic efficiency under visible light.•A detailed degradation pathway of RhB was illustrated.•2% Bi2S3/Bi2Sn2O7 with maximal photocatalytic degradation efficiency (RhB) of 94.4%.•h+ is demonstrated as main reactive species in the photocatalytic process.Bi2S3-sensitized Bi2Sn2O7 (BSO) photocatalyst (Bi2S3/BSO) was successfully synthesized through a facile and economical ion exchange method between BSO and thioacetamide (CH3CSNH2). The as-prepared photocatalysts were characterized using X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray (EDX) spectroscopy, Brunauer-Emmett-Teller (BET) surface area, X-ray photoelectron spectroscopy (XPS), Raman spectra, and UV–vis diffuse reflection spectroscopy (DRS). The obtained Bi2S3/BSO composite showed excellent photocatalytic performance for decomposing rhodamine B (RhB) compared with pure BSO under visible light irradiation (λ > 420 nm). 2% Bi2S3/BSO exhibited the highest photocatalytic activity and excessive amount of Bi2S3 would result in the decrease of photocatalytic activity of BSO. On the basis of the calculated energy band positions, the mechanism of enhanced photocatalytic activity was proposed.
Co-reporter:Yunfang Chen, Jianzhang Fang, Shaoyou Lu, Yan Wu, Dazhi Chen, Liyan Huang, Weicheng Xu, Ximiao Zhu, Zhanqiang Fang
Materials Research Bulletin 2015 64() pp: 97-105
Publication Date(Web):
DOI:10.1016/j.materresbull.2014.12.040
Co-reporter:Shuxing Wu, Jianzhang Fang, Xiaoting Hong, K. S. Hui and Yunfang Chen
Dalton Transactions 2014 vol. 43(Issue 6) pp:2611-2619
Publication Date(Web):06 Nov 2013
DOI:10.1039/C3DT52885E
Rectorite was composited with BiOI to extend its applicability as an applied material with high adsorptive capacity and photocatalytic activity. The facile synthesis process involved ultrasonic irradiation and in situ reaction. The physicochemical properties of the as-prepared samples were characterized by means of X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), N2 adsorption–desorption isotherms, and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). Rhodamine B (RhB), a typical organic contaminant, was used as the model contaminant to evaluate the adsorption capacity and photocatalytic performance of the prepared BiOI–rectorite composite. The adsorption process was found to obey pseudo-second-order kinetics. The equilibrium adsorption was well-modeled using the Freundlich adsorption isotherm. High photocatalytic activity under visible light irradiation was observed.
Co-reporter:Shuxing Wu;Weicheng Xu;Chaoping Cen
Journal of Chemical Technology and Biotechnology 2013 Volume 88( Issue 10) pp:1828-1835
Publication Date(Web):
DOI:10.1002/jctb.4034
Abstract
Background
Water pollution is a serious problem for the entire world. Photocatalysis is an accepted way to decontaminate water. As the key factor influencing photocatalysis, an environmentally friendly photocatalyst should possess good visible-light-response. Additionally, an efficient catalyst should have good separation of e-/h+ pairs. On account of the special f electron orbital structure, the ions of rare earths exhibit the ability to accelerate the abruption of photogenerated e-/h+ pairs. In this work, visible-light-driven α-Bi2O3 enhanced using Pr3+ doping was prepared by hydrothermal synthesis.
Results
The as-prepared catalysts calcined at 500 °C exhibited only the characteristic peaks of Bi2O3 and presented irregular plate-like structures. The separation efficiency for electron–hole was enhanced when α-Bi2O3 was doped with Pr. The photocatalytic activities, which were evaluated by degradation of Rhodamine B (RhB) and 2,4-dichlorophenol (2,4-DCP) under visible light irradiation, was enhanced significantly by doping Pr into α-Bi2O3.
Conclusion
Doping α-Bi2O3 with Pr significantly enhanced the photocatalytic activity. The optimum percentage of doped pr was 3.0 mol %. ·OH radicals were the dominant photooxidant. This study demonstrates an efficient pathway to improve the photocatalytic performance of α-Bi2O3. © 2013 Society of Chemical Industry
Co-reporter:Shuxing Wu, Jianzhang Fang, Weicheng Xu, Chaoping Cen
Journal of Molecular Catalysis A: Chemical 2013 Volume 373() pp:114-120
Publication Date(Web):July 2013
DOI:10.1016/j.molcata.2013.03.012
•The visible light responsive bismuth-modified rectorite was prepared by ultrasonic-assisted method.•Bismuth-modified rectorite showed strong adsorbility and exhibited an excellent photocatalytic activity.•OH radicals were the main active specials in the photocatalytic system.Herein, we reported an ultrasonic-assisted synthesis of bismuth-modified rectorite with high visible light-induced photocatalytic activity. The as-synthesized samples were characterized by XRD, FT-IR, FESEM, TEM, BET, and UV–vis DRS techniques. Two toxic and nonbiodegradable organic compounds, Rhodamine B (RhB) and 2,4-dichlorophenol (DCP), were chosen as the target pollutants to characterize the adsorption performance and photocatalytic activity. The results showed that the prepared samples possessed strong adsorbility and exhibited high efficient photocatalytic activity under visible light irradiation. The excellent photocatalytic activity of bismuth-modified rectorite was ascribed to the strong adsorption ability, the interconnected heterojunction of Bi2O3 and Bi5O7NO3, and the produced OH. Finally, the possible mechanism was presented.
Co-reporter:Zhang Liu, Weicheng Xu, Jianzhang Fang, Xiaoxin Xu, Shuxing Wu, Ximiao Zhu, Zehua Chen
Applied Surface Science 2012 Volume 259() pp:441-447
Publication Date(Web):15 October 2012
DOI:10.1016/j.apsusc.2012.07.063
Abstract
Herein, a reverse microemulsion route was developed to synthesize bismuth oxyiodide (BiOI) nanocrystals and reduced graphene oxide (RGO) nanocomposites as a highly efficient photocatalyst, and both the formation of BiOI and the reduction of RGO were achieved in situ in microemulsions simultaneously at low temperature (60 °C). The uniform nanocrystal size and structure were indicated by XRD, TEM, and the reduction of GO by ascorbic acid was evidenced by FTIR, XPS, and Raman spectra techniques. The enhanced photoactivity of RGO/BiOI nanocomposites under visible light was attributed to improved light absorption and efficient charge separation and transportation.
Co-reporter:Zhang Liu, Xiaoxin Xu, Jianzhang Fang, Ximiao Zhu, Jinhui Chu, Baojian Li
Applied Surface Science 2012 Volume 258(Issue 8) pp:3771-3778
Publication Date(Web):1 February 2012
DOI:10.1016/j.apsusc.2011.12.025
Abstract
Reverse microemulsions, consisting of n-hexanol, Triton X-100, Cyclohexane and aqueous salt solutions, were used to synthesize BiOI, TiO2 and BiOI/TiO2 hybrid nanoparticles at room temperature. The particles had been characterized by X-ray powder diffraction, FT-IR spectra, TG-DSC analysis, nitrogen sorption, electron microscopy, and UV–vis diffuse reflectance spectroscopy. The photocatalytic properties of those particles were evaluated by degradation of methyl orange under visible light irradiation. The BiOI/TiO2 composites showed about 5 times higher photocatalytic performances than BiOI when the mole ratio of BiOI to TiO2 was 75%. The remarkable enhancement in the visible light photocatalytic activities of the BiOI/TiO2 heterostructures could be first attributed to the effective electron–hole separations at the interfaces of the two semiconductors, which facilitated the transfer of the photoinduced carriers. Meanwhile, the heterojunction formed between BiOI and TiO2 would further retard the recombination of photoinduced carriers. In addition, high degree of crystallization, bimodal porous structure, relative large specific surface area, and appropriate energy band gap have great contribution to the enhancement of photocatalytic performance.
Co-reporter:Zhang Liu, Jianzhang Fang, Weicheng Xu, Xiaoxin Xu, Shuxing Wu, Ximiao Zhu
Materials Letters 2012 Volume 88() pp:82-85
Publication Date(Web):1 December 2012
DOI:10.1016/j.matlet.2012.07.109
The synthesis of one-dimension (1D) Bi2S3 nanorods has been successfully achieved through the transformation of BiOI nanosheets at low hydrothermal temperature. Their crystallization, structure and morphology transformation processes were characterized in detail. Crystallite (Bi(Bi2S3)9I3)0.6667 nanorods were identified as intermediate products in the process, and they were chemically etched and split during the hydrothermal reaction into narrower Bi2S3 nanorods, which tend to bundle together with diameters range from 40 to 100 nm and lengths up to ∼800 nm. The possible transformation process of tetragonal BiOI nanosheets to orthorhombic Bi2S3 nanorods was investigated to better understand the potential application of this view for constructing novel nanostructures.Graphical abstractHighlights► Synthesis of Bi2S3 nanorods has been achieved using BiOI as a sacrificing template. ► The synthetic experiment was carried out at low hydrothermal temperature. ► The transformation of BiOI nanosheets to Bi2S3 nanorods has been observed in detail. ► Possible formation mechanism of Bi2S3 nanorods was proposed.
Co-reporter:Shuxing Wu;Xiaoxin Xu;Zhang Liu;Ximiao Zhu ;Weicheng Xu
Photochemistry and Photobiology 2012 Volume 88( Issue 5) pp:1205-1210
Publication Date(Web):
DOI:10.1111/j.1751-1097.2012.01164.x
Abstract
In this paper, Bi2O3 and rare earth (La, Ce)-doped Bi2O3 visible-light-driven photocatalysts were prepared in a Triton X-100/n-hexanol/cyclohexane/water reverse microemulsion. The resulting materials were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) surface area, photoluminescence spectra (PLS) and UV–Vis diffuse reflectance spectroscopy. The XRD patterns of the as-prepared catalysts calcined at 500°C exhibited only the characteristic peaks of monoclinic α-Bi2O3. PLS analysis implied that the separation efficiency for electron-hole has been enhanced when Bi2O3 was doped with rare earth. UV–Vis diffuse reflectance spectroscopy measurements presented an extension of light absorption into the visible region. The photocatalytic activity of the samples was evaluated by degradation of methyl orange (MO) and 2,4-dichlorophenol (2,4-DCP). The results displayed that the photocatalytic activity of rare earth-doped Bi2O3 was higher than that of dopant-free Bi2O3. The optimal dopant amount of La or Ce was 1.0 mol%. And the mechanisms of influence on the photocatalytic activity of the catalysts were discussed.
Co-reporter:Z. Jian;J. Fang;F. Peng
Journal of Chemical Technology and Biotechnology 2010 Volume 85( Issue 6) pp:860-865
Publication Date(Web):
DOI:10.1002/jctb.2379
Abstract
BACKGROUND: Microemulsion is the easiest and cleanest of the popular methods of synthesizing nanomaterial. This work investigated the possibility of forming a single-phase microemulsion using ethanediyl-α,β-bis (cetyldimethylammonium bromide), termed EbCDAB, in a n-hexanol/water system, and looked for the best scale of microemulsion to synthesize TiO2 to give the best cleaning of organic pollution.
RESULTS: Results confirm that EbCDAB, n-hexanol and water form a microemulsion system, and this system is an effective way to synthesize nanoparticles of TiO2. Photo catalysis experiments showed sample E6−3 to be the best catalyst, and it decomposed 82% of Methyl Orange (10 mg L−1) in 60 min under UV-light irradiation. E6−3 had 1.4 times higher activity than the commercial P25. Analyses using transmission electron microscopy (TEM), X-ray diffraction (XRD), thermographic differential scanning calorimetry (TG-DSC) and Fourier transform infrared microscopy (FT-IR), showed that particles of E6−3 were of size around 11 nm and of anatase phase.
CONCLUSION: The best microemulsion was found to have weight ratio n-hexanol:EbCDAB:water of 6:3:1. At this ratio, TiO2 nanoparticles were easily produced. Copyright © 2010 Society of Chemical Industry
Co-reporter:Zicong Jian;Yuying Pu;Zhiping Ye
Photochemistry and Photobiology 2010 Volume 86( Issue 5) pp:1016-1021
Publication Date(Web):
DOI:10.1111/j.1751-1097.2010.00773.x
Abstract
Microemulsion is the easiest and cleanest of the popular methods of synthesizing nanomaterial. This work synthesized the nanosized La-TiO2 and Ce-TiO2 particles through the hydrolyzation of tetrabutyl titanate in a Triton X-100/n-hexanol/cyclohexane/water reverse microemulsion. The particles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform-infrared spectroscopy (FT-IR) and thermogravimetry (TG). The photocatalytic activity was evaluated by photocatalytic degradation of methyl orange (MO) under ultraviolet light and visible light irradiation. The results showed that reverse microemulsion produced the nanosized and well-separated particles, which are obviously in degrading MO. Comparing the pure TiO2 with doping TiO2, the doping ones are smaller and have better photocatalytic activity, which was best at the molar content of 0.1% for La, whereas for Ce it was 0.5%.
Co-reporter:Weihua Feng, Jianzhang Fang, Guangying Zhou, Lanxin Zhang, Shaoyou Lu, Shuxing Wu, Yi Chen, Yu Ling, Zhanqiang Fang
Molecular Catalysis (June 2017) Volume 434() pp:69-79
Publication Date(Web):1 June 2017
DOI:10.1016/j.mcat.2017.03.004
•Hybrid photocatalyst Bi@BiOCl/g-C3N4 composite was prepared by a solvothermal method followed by a surface etching.•The photocatalytic activity of Bi@BiOCl/g-C3N4 is good in both pollutants degradation and Cr(VI) reduction.•Its Z-scheme charge transfer and intimate interfaces between different components result in efficient photocatalysis.•Bi metal serves as Z-scheme bridge in Bi@BiOCl/g-C3N4.•Its core–shell structure leads to good stability.Bi@BiOCl/g-C3N4 was prepared via a solvothermal method followed by a surface oxidation treatment. In this hybrid structure, Bi spheres were deposited on p-g-C3N4, and BiOCl was coated on the surface of Bi spheres except for the interfaces between g-C3N4 and metallic Bi. A series of characterization techniques proved its successful preparation. It exhibited high photocatalytic activities in RhB and 2,4-DCP degradation and Cr(VI) reduction under simulated solar light illumination. Besides, it exhibited efficient photo-mineralization of 2,4-DCP. Its efficient photocatalysis was attributed to its high separation efficiency of charge carriers and high redox potential of its photo-generated electrons and holes, which resulted from the Z-scheme photo-induced charges transfer in Bi@BiOCl/g-C3N4. Besides, the metallic Bi was served as Z-scheme bridge in Bi@BiOCl/g-C3N4, which would accelerate the Z-scheme photo-induced charges transfer. Meanwhile, its core–shell structure led to high stability during photocatalysis. Afterwards, its photocatalytic mechanisms for organic pollutants degradation and Cr(VI) reduction were illustrated. The Z-scheme core–shell structured photocatalyst in our work is a promising candidate for the degradation of organic pollutants and reduction of heavy metal ions.Download full-size image
Co-reporter:Shuxing Wu, Jianzhang Fang, Xiaoting Hong, K. S. Hui and Yunfang Chen
Dalton Transactions 2014 - vol. 43(Issue 6) pp:NaN2619-2619
Publication Date(Web):2013/11/06
DOI:10.1039/C3DT52885E
Rectorite was composited with BiOI to extend its applicability as an applied material with high adsorptive capacity and photocatalytic activity. The facile synthesis process involved ultrasonic irradiation and in situ reaction. The physicochemical properties of the as-prepared samples were characterized by means of X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), N2 adsorption–desorption isotherms, and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). Rhodamine B (RhB), a typical organic contaminant, was used as the model contaminant to evaluate the adsorption capacity and photocatalytic performance of the prepared BiOI–rectorite composite. The adsorption process was found to obey pseudo-second-order kinetics. The equilibrium adsorption was well-modeled using the Freundlich adsorption isotherm. High photocatalytic activity under visible light irradiation was observed.
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