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Author

Li Wang

Bio: Li Wang is an academic researcher from Southwest Petroleum University. The author has contributed to research in topics: Photocatalysis & Optics. The author has an hindex of 12, co-authored 16 publications receiving 991 citations.
Topics: Photocatalysis, Optics, Physics, Laser, Bismuth

Papers
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Journal ArticleDOI
TL;DR: This work presents the first report about the facet-dependent photocatalytic performance of bismuth-rich Bi-O-X photocatalyst, synthesizing two Bi5O7I nanosheets with different dominant facets using either molecular precursor hydrolysis or calcination.
Abstract: Bismuth-rich bismuth oxyhalides (Bi–O–X; X = Cl, Br, I) display high photocatalytic reduction activity due to the promoting conduction band potential. In this work, two Bi5O7I nanosheets with different dominant facets were synthesized using either molecular precursor hydrolysis or calcination. Crystal structure characterizations, included X-ray diffraction patterns (XRD), field emission electron microscopy and fast Fourier transformation (FFT) images, showed that hydrolysis and calcination resulted in the dominant exposure of {100} and {001} facets, respectively. Photocatalytic data revealed that Bi5O7I–001 had a higher activity than Bi5O7I–100 for N2 fixation and dye degradation. Photoelectrochemical data revealed that Bi5O7I–001 had higher photoinduced carrier separation efficiency than Bi5O7I–100. The band structure analysis also used to explain the underlying photocatalytic mechanism based on the different conduction band position. This work presents the first report about the facet-dependent photocat...

308 citations

Journal ArticleDOI
TL;DR: In this article, the photo-induced carrier separation efficiency of g-C 3 N 4 /Bi 4 O 5 I 5 I 2 heterojunction was investigated using X-ray diffraction patterns (XRD), field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectra (DRS), and XPS.
Abstract: Heterojunction is an effectively construction to improve the photocatalytic activity due to the excellent photo-induced carrier separation efficiency. In this paper, g-C 3 N 4 /Bi 4 O 5 I 2 heterojunction was prepared and characterized by X-ray diffraction patterns (XRD), field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), UV–vis diffuse reflectance spectra (DRS) and X-ray photoelectron spectroscopy (XPS). The photocatalytic data showed that g-C 3 N 4 /Bi 4 O 5 I 2 heterojunction had higher activity than pure g-C 3 N 4 and Bi 4 O 5 I 2 . At an optimal ratio of 1.0 mol% (11.4 wt% of Bi 4 O 5 I 2 ), g-C 3 N 4 /Bi 4 O 5 I 2 photocatalyst showed the highest photocatalytic reduction activity for CO 2 conversion with 45.6 μmol h −1 g −1 CO generation. Photocurrent and electrochemical impedance (EIS) spectroscopy revealed that higher photo-induced carrier separation efficiency of g-C 3 N 4 /Bi 4 O 5 I 2 . Z-scheme charge transfer mode was proved by I 3 − /I − redox mediator existence and superoxide radical (O 2 − ) and hydroxyl radical ( OH) quantification experiments.

245 citations

Journal ArticleDOI
TL;DR: In this paper, a solid solution of bismuth-rich Bi4O5BrxI2-x was prepared applying the molecular precursor method, which was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM), element mapping, Brunauer-Emmett-Teller surface analysis (BET), UV-vis diffuse reflectance spectroscopy (DRS), and Xray photoelectron spectroscope (XPS).
Abstract: Bismuth oxyhalides (BiOX, X = Br, I) photocatalysts are rarely applied for photocatalytic reduction reaction withthe photo-induced electron, as this is impeded by their low conduction band. As a widely used approach for enhancing the photocatalytic reduction activity, bismuth-rich strategy results the bismuth content of BiOX photocatalysts increasing. In this paper, a solid solutions of bismuth-rich Bi4O5BrxI2-x were prepared applying the molecular precursor method. Bi4O5BrxI2-x were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), element mapping, Brunauer–Emmett–Teller surface analysis (BET), UV–vis diffuse reflectance spectroscopy (DRS), and X-ray photoelectron spectroscopy (XPS). The obtained photocatalytic data showed that Bi4O5BrxI2-x solid solutions had higher photocatalytic activities than Bi4O5Br2 and Bi4O5I2. At an optimal ratio of x = 1, the Bi4O5BrI photocatalyst showed the highest photocatalytic reduction activity for CO2 conversion (22.85 μmol h−1 g−1 CO generation, AQE was 0.372 at 400 nm) and Cr(VI) removal (88%). CO2 adsorption data and CO2 temperature programmed desorption (CO2-TPD) revealed that Bi4O5BrI exhibited the highest chemical adsorption ability of CO2 molecules Photocurrent and electrochemical impedance (EIS) spectroscopy demonstrated the enhanced photo-induced carrier separation efficiency of Bi4O5BrI. These mechanistic studies suggest that Bi4O5BrxI2-x solid solutions are excellent photocatalysts for solar fuel generation and environmental remediation.

154 citations

Journal ArticleDOI
Yang Bai1, Chen Ting1, Pingquan Wang1, Li Wang, Liqun Ye1 
TL;DR: In this paper, a bismuth-rich strategy was used to promote the CB position of Bi4O5X2 nanosheets for photocatalytic H2 evolution.

149 citations

Journal ArticleDOI
TL;DR: A novel donor-acceptor (D-A) COF that was constructed by the Schiff base reaction of carbazole-triazine based D-A monomers and possessed a suitable energy band structure, strong visible-light-harvesting and rich nitrogen sites and DFT calculations suggest that nitrogen atoms in the triazine rings may be photocatalytic active sites.
Abstract: Visible-light-driven CO2 reduction to valuable chemicals without sacrificial agents and cocatalysts remains challenging, especially for metal-free photocatalytic systems. Herein, a novel donor-acceptor (D-A) covalent organic framework (CT-COF) was constructed by the Schiff-base reaction of carbazole-triazine based D-A monomers and possessed a suitable energy band structure, strong visible-light-harvesting, and abundant nitrogen sites. CT-COF as a metal-free photocatalyst could reduce CO2 with gaseous H2 O to CO as the main carbonaceous product with approximately stoichiometric O2 evolution under visible-light irradiation and without cocatalyst. The CO evolution rate (102.7 μmol g-1 h-1 ) was 68.5 times that of g-C3 N4 under the same conditions. In situ Fourier-transform (FT)IR analysis indicated that CT-COF could adsorb and activate the CO2 and H2 O molecules and that COOH* species may be a key intermediate. DFT calculations suggested that nitrogen atoms in the triazine rings may be photocatalytically active sites.

141 citations


Cited by
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Journal ArticleDOI
TL;DR: Various cocatalysts, such as the biomimetic, metal-based,Metal-free, and multifunctional ones, and their selectivity for CO2 photoreduction are summarized and discussed, along with the recent advances in this area.
Abstract: Photoreduction of CO2 into sustainable and green solar fuels is generally believed to be an appealing solution to simultaneously overcome both environmental problems and energy crisis. The low selectivity of challenging multi-electron CO2 photoreduction reactions makes it one of the holy grails in heterogeneous photocatalysis. This Review highlights the important roles of cocatalysts in selective photocatalytic CO2 reduction into solar fuels using semiconductor catalysts. A special emphasis in this review is placed on the key role, design considerations and modification strategies of cocatalysts for CO2 photoreduction. Various cocatalysts, such as the biomimetic, metal-based, metal-free, and multifunctional ones, and their selectivity for CO2 photoreduction are summarized and discussed, along with the recent advances in this area. This Review provides useful information for the design of highly selective cocatalysts for photo(electro)reduction and electroreduction of CO2 and complements the existing reviews on various semiconductor photocatalysts.

1,365 citations

Journal ArticleDOI
TL;DR: In this article, a review concisely compiles the recent progress in the fabrication, modification, and major applications of the direct Z-scheme photocatalysts; the latter include water splitting, carbon dioxide reduction, degradation of pollutants, and biohazard disinfection.

1,013 citations

Journal ArticleDOI
TL;DR: A panorama of the latest advancements in the rational design and development of semiconductor polymeric graphitic carbon nitride (g-C3N4) photocatalysts for visible-light-induced hydrogen evolution reaction (HER) is presented in this paper.
Abstract: Semiconductor polymeric graphitic carbon nitride (g-C3N4) photocatalysts have attracted dramatically growing attention in the field of the visible-light-induced hydrogen evolution reaction (HER) because of their facile synthesis, easy functionalization, attractive electronic band structure, high physicochemical stability and photocatalytic activity. This review article presents a panorama of the latest advancements in the rational design and development of g-C3N4 and g-C3N4-based composite photocatalysts for HER application. Concretely, the review starts with the development history, synthetic strategy, electronic structure and physicochemical characteristics of g-C3N4 materials, followed by the rational design and engineering of various nanostructured g-C3N4 (e.g. thinner, highly crystalline, doped, and porous g-C3N4) photocatalysts for HER application. Then a series of highly efficient g-C3N4 (e.g., metal/g-C3N4, semiconductor/g-C3N4, metal organic framework/g-C3N4, carbon/g-C3N4, conducting polymer/g-C3N4, sensitizer/g-C3N4) composite photocatalysts are exemplified. Lastly, this review provides a comprehensive summary and outlook on the major challenges, opportunities, and inspiring perspectives for future research in this hot area on the basis of pioneering works. It is believed that the emerging g-C3N4-based photocatalysts will act as the “holy grail” for highly efficient photocatalytic HER under visible-light irradiation.

717 citations

Journal ArticleDOI
TL;DR: In this article, the authors summarized the widely accepted pathways of photocatalytic CO2 reduction reactions and analyzed the important factors affecting product selectivity, mainly including light-excitation attributes, band structure of photocATalysts, separation of photogenerated charge carriers, adsorption/activation of reactants, surface active sites of catalytic reaction, and adaption/desorption of intermediates.

569 citations

Journal ArticleDOI
TL;DR: This study shows the first synthesis of self-assembled 5 nm diameter Bi5 O7 Br nanotubes with strong nanotube structure, suitable absorption edge, and many exposed surface sites, which are favorable for furnishing sufficient visible light-induced OVs to realize excellent and stable photoreduction of atmospheric N2 into NH3 in pure water.
Abstract: Solar-driven reduction of dinitrogen (N2 ) to ammonia (NH3 ) is severely hampered by the kinetically complex and energetically challenging multielectron reaction. Oxygen vacancies (OVs) with abundant localized electrons on the surface of bismuth oxybromide-based semiconductors are demonstrated to have the ability to capture and activate N2 , providing an alternative pathway to overcome such limitations. However, bismuth oxybromide materials are susceptible to photocorrosion, and the surface OVs are easily oxidized and therefore lose their activities. For realistic photocatalytic N2 fixation, fabricating and enhancing the stability of sustainable OVs on semiconductors is indispensable. This study shows the first synthesis of self-assembled 5 nm diameter Bi5 O7 Br nanotubes with strong nanotube structure, suitable absorption edge, and many exposed surface sites, which are favorable for furnishing sufficient visible light-induced OVs to realize excellent and stable photoreduction of atmospheric N2 into NH3 in pure water. The NH3 generation rate is as high as 1.38 mmol h-1 g-1 , accompanied by an apparent quantum efficiency over 2.3% at 420 nm. The results presented herein provide new insights into rational design and engineering for the creation of highly active catalysts with light-switchable OVs toward efficient, stable, and sustainable visible light N2 fixation in mild conditions.

567 citations