In this work, BiV04 powders were synthesized by a sol-gel method, and the BiV04 gels with different calcination temperature were investigated by X-ray diffraction （XRD）. Absorption range and band gap energy, which a...In this work, BiV04 powders were synthesized by a sol-gel method, and the BiV04 gels with different calcination temperature were investigated by X-ray diffraction （XRD）. Absorption range and band gap energy, which are respon- sible for the observed photocatalyst behavior, were investigated by UV/vis diffuse reflectance spectroscopy （DRS） for pure and silver oxide loaded BiV04. Pbotocatalytic properties of the prepared samples were examined by studying the degradation of the methyl orange. When using NaCI02 as an electron acceptor, the possible photocatalytic mech- anism has been discussed by photocatalytic reactions. With the help of electron acceptor, the results show clearly that the BiV04 loaded silver oxide exhibited superior photocatalytic activity in simulated dye wastewater treatment.展开更多
An amorphous ferric oxide layer was prepared on a bismuth vanadate photoanode.This resulted in improved charge carrier separation and surface catalytic performance compared with the photoanode without the oxide layer....An amorphous ferric oxide layer was prepared on a bismuth vanadate photoanode.This resulted in improved charge carrier separation and surface catalytic performance compared with the photoanode without the oxide layer.The photocurrent of the oxide‐layer‐containing photoanode was2.52mA/cm2at1.23V versus the reversible hydrogen electrode,in potassium phosphate buffer,(0.5mol/L,pH=7.0).The amorphous ferric oxide layer on the photoanode contained low‐valence‐state iron species(FeII),which enabled efficient hole extraction and transfer.展开更多
BiVO_(4)is one of the most promising photoanode materials for photoelectrochemical(PEC)solar energy conversion,but it still suffers from poor photocurrent density due to insufficient light‐harvesting efficiency(LHE),...BiVO_(4)is one of the most promising photoanode materials for photoelectrochemical(PEC)solar energy conversion,but it still suffers from poor photocurrent density due to insufficient light‐harvesting efficiency(LHE),weak photogenerated charge separation efficiency(Φ_(Sep)),and low water oxidation efficiency(Φ_(OX)).Herein,we tackle these challenges of the BiVO_(4)photoanodes using systematic engineering,including catalysis engineering,bandgap engineering,and morphology engineering.In particular,we deposit a NiCoO_(x)layer onto the BiVO_(4)photoanode as the oxygen evolution catalyst to enhance theΦ_(OX)of Fe‐g‐C_(3)N_(4)/BiVO_(4)for PEC water oxidation,and incorporate Fe‐doped graphite‐phase C_(3)N_(4)(Fe‐g‐C_(3)N_(4))into the BiVO_(4)photoanode to optimize the bandgap and surface areas to subsequently expand the light absorption range of the photoanode from 530 to 690 nm,increase the LHE andΦ_(Sep),and further improve the oxygen evolution reaction activity of the NiCoO_(x)catalytic layer.Consequently,the maximum photocurrent density of the as‐prepared NiCoO_(x)/Fe‐g‐C_(3)N_(4)/BiVO_(4)is remarkably boosted from 4.6 to 7.4 mA cm^(−2).This work suggests that the proposed systematic engineering strategy is exceptionally promising for improving LHE,Φ_(Sep),andΦ_(OX)of BiVO_(4)‐based photoanodes,which will substantially benefit the design,preparation,and large‐scale application of next‐generation high‐performance photoanodes.展开更多
Although spatial charge separation between different facets of semiconductor crystals has been recognized as a general strategy in photocatalysis, the vital role of crystal morphology symmetry in charge separation pro...Although spatial charge separation between different facets of semiconductor crystals has been recognized as a general strategy in photocatalysis, the vital role of crystal morphology symmetry in charge separation properties still remains elusive. Herein,taking monoclinic bismuth vanadate(BiVO_(4)) as a platform, we found distinct charge separation difference via rationally tailoring the morphology symmetry from octahedral to truncated octahedral crystals. For octahedral BiVO_(4), photogenerated electrons and holes can be separated between edges and quasi-equivalent facets. However, as for truncated octahedral crystals,photogenerated electrons tend to transfer to {010} facets while photogenerated holes prefer to accumulate on {120} facets, thus realizing the spatial separation of photogenerated charge between different facets. Morphology tailoring of BiVO_(4) crystals leads to a significantly improved photogenerated charge separation efficiency and photocatalytic water oxidation activity. The built-in electric field for driving the separation of photogenerated electrons and holes is considered to be modulated by tuning the morphology symmetry of BiVO_(4) crystals. This work discloses the significant roles of morphology symmetry in photogenerated charge separation and facilitates the rational design of artificial photocatalysts.展开更多
The development of new heterostructures with high photoactivity is a breakthrough for the limitation of solar-driven water splitting.Here,we first introduce indium oxide(In_(2)O_(3))nanorods(NRs)as a novel electron tr...The development of new heterostructures with high photoactivity is a breakthrough for the limitation of solar-driven water splitting.Here,we first introduce indium oxide(In_(2)O_(3))nanorods(NRs)as a novel electron transport layer for bismuth vanadate(BiVO_(4))with a short charge diffusion length.In_(2)O_(3)NRs reinforce the electron transport and hole blocking of BiVO_(4),surpassing the state-of-the-art photoelectrochemical performances of BiVO_(4)-based photoanodes.Also,a tannin-nickel-iron complex(TANF)is used as an oxygen evolution catalyst to speed up the reaction kinetics.The final TANF/BiVO_(4)/In_(2)O_(3)NR photoanode generates photocurrent densities of 7.1 mAcm^(−2) in sulfite oxidation and 4.2 mA cm^(−2) in water oxidation at 1.23 V versus the reversible hydrogen electrode.Furthermore,the“artificial leaf,”which is a tandem cell with a perovskite/silicon solar cell,shows a solar-to-hydrogen conversion efficiency of 6.2%for unbiased solar water splitting.We reveal significant advances in the photoactivity of TANF/BiVO_(4)/In_(2)O_(3)NRs from the tailored nanostructure and band structure for charge dynamics.展开更多
Monoclinic BiVO4 with multiple morphologies and/or porous structures were fabricated using the hydrothermal strategy. The materials were characterized by means of the XRD, Raman, TGA/DSC, SEM, XPS, and UV-Vis techniqu...Monoclinic BiVO4 with multiple morphologies and/or porous structures were fabricated using the hydrothermal strategy. The materials were characterized by means of the XRD, Raman, TGA/DSC, SEM, XPS, and UV-Vis techniques. The photocatalytic activities of the BiVO4 materials were evaluated for the degradation of Methyl Orange under visible-light irradiation. It is observed that pH value and surfactant exerted a great effect on the morphology and pore structure of the BiVO4 product. Spherical BiVO4 with porous structures, flower-cluster-like BiVO4, and flower-bundle-like BiVO4 were generated hydrothermally at 100°C with poly（vinyl pyrrolidone） （PVP） and urea （pH = 2） and at 160°C with NaHCO3 （pH = 7 and 8）, respectively. The PVP-derived BiVO4 showed much higher surface areas （5.0-8.4 m2/g） and narrower bandgap energies （2.45-2.49 eV）. The best photocatalytic performance of the spherical BiVO4 material with a surface area of 8.4 m2/g was associated with its higher surface area, narrower bandgap energy, higher surface oxygen vacancy density, and unique porous architecture.展开更多
Photoelectrochemical(PEC)technology is considered to be a promising approach for solar-driven hydrogen production with zero emissions.Bismuth vanadate(BiVO_(4))is a kind of photocatalytic material with strong photoact...Photoelectrochemical(PEC)technology is considered to be a promising approach for solar-driven hydrogen production with zero emissions.Bismuth vanadate(BiVO_(4))is a kind of photocatalytic material with strong photoactivity in the visible light region and appropriate band gap for PEC water splitting.However,the solar-to-hydrogen efficiency(STH)of BiVO_(4)is far away from the 10%target needed for practical application due to its poor charge separation ability.Therefore,this review attempts to summarize the strategies for improving the photocurrent density and especially hydrogen production of BiVO_(4)materials through PEC techniques in the last three years,such as doping nonmetal and metal elements,depositing noble metals,constructing heterojunctions,coupling with carbon and metalorganic framework(MOF)materials to further enhance the PEC performance of BiVO_(4)photoanode.This review aims to serve as a general guideline to fabricate highly efficient BiVO_(4)-based materials for PEC water splitting.展开更多
基金Supported by the Education Department of Heilongjiang Province(12541111)the Program for Innovative Research Team in University of Heilongjiang Province(2013TD008)the Key Laboratory of Green Chemical Engineering and Technology of College of Heilongjiang Province and Harbin University of Science and Technology and the Technology and Innovative Experimental Project of Harbin University of Science and Technology
文摘In this work, BiV04 powders were synthesized by a sol-gel method, and the BiV04 gels with different calcination temperature were investigated by X-ray diffraction （XRD）. Absorption range and band gap energy, which are respon- sible for the observed photocatalyst behavior, were investigated by UV/vis diffuse reflectance spectroscopy （DRS） for pure and silver oxide loaded BiV04. Pbotocatalytic properties of the prepared samples were examined by studying the degradation of the methyl orange. When using NaCI02 as an electron acceptor, the possible photocatalytic mech- anism has been discussed by photocatalytic reactions. With the help of electron acceptor, the results show clearly that the BiV04 loaded silver oxide exhibited superior photocatalytic activity in simulated dye wastewater treatment.
基金supported by the National Natural Science Foundation of China(21373083,21573068)Program of Shanghai Subject Chief Scientist(15XD1501300)+1 种基金the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education MinistryScience Technology Commission of Shanghai Municipality(14JC1490900)~~
文摘An amorphous ferric oxide layer was prepared on a bismuth vanadate photoanode.This resulted in improved charge carrier separation and surface catalytic performance compared with the photoanode without the oxide layer.The photocurrent of the oxide‐layer‐containing photoanode was2.52mA/cm2at1.23V versus the reversible hydrogen electrode,in potassium phosphate buffer,(0.5mol/L,pH=7.0).The amorphous ferric oxide layer on the photoanode contained low‐valence‐state iron species(FeII),which enabled efficient hole extraction and transfer.
基金Natural Science Foundation of China,Grant/Award Number:22108042Guangzhou(202201020147)。
文摘BiVO_(4)is one of the most promising photoanode materials for photoelectrochemical(PEC)solar energy conversion,but it still suffers from poor photocurrent density due to insufficient light‐harvesting efficiency(LHE),weak photogenerated charge separation efficiency(Φ_(Sep)),and low water oxidation efficiency(Φ_(OX)).Herein,we tackle these challenges of the BiVO_(4)photoanodes using systematic engineering,including catalysis engineering,bandgap engineering,and morphology engineering.In particular,we deposit a NiCoO_(x)layer onto the BiVO_(4)photoanode as the oxygen evolution catalyst to enhance theΦ_(OX)of Fe‐g‐C_(3)N_(4)/BiVO_(4)for PEC water oxidation,and incorporate Fe‐doped graphite‐phase C_(3)N_(4)(Fe‐g‐C_(3)N_(4))into the BiVO_(4)photoanode to optimize the bandgap and surface areas to subsequently expand the light absorption range of the photoanode from 530 to 690 nm,increase the LHE andΦ_(Sep),and further improve the oxygen evolution reaction activity of the NiCoO_(x)catalytic layer.Consequently,the maximum photocurrent density of the as‐prepared NiCoO_(x)/Fe‐g‐C_(3)N_(4)/BiVO_(4)is remarkably boosted from 4.6 to 7.4 mA cm^(−2).This work suggests that the proposed systematic engineering strategy is exceptionally promising for improving LHE,Φ_(Sep),andΦ_(OX)of BiVO_(4)‐based photoanodes,which will substantially benefit the design,preparation,and large‐scale application of next‐generation high‐performance photoanodes.
基金supported by the National Key Research and Development Program of China (2021YFA1502300)by the Fundamental Research Funds for the Central Universities (20720220011)+3 种基金conducted by the Fundamental Research Center of Artificial Photosynthesis (FReCAP)financially supported by the National Natural Science Foundation of China (22088102)the support from National Natural Science Foundation of China (22090033, 22272165)Youth Innovation Promotion Association of Chinese Academy of Sciences and the National Youth Talent Support Program。
文摘Although spatial charge separation between different facets of semiconductor crystals has been recognized as a general strategy in photocatalysis, the vital role of crystal morphology symmetry in charge separation properties still remains elusive. Herein,taking monoclinic bismuth vanadate(BiVO_(4)) as a platform, we found distinct charge separation difference via rationally tailoring the morphology symmetry from octahedral to truncated octahedral crystals. For octahedral BiVO_(4), photogenerated electrons and holes can be separated between edges and quasi-equivalent facets. However, as for truncated octahedral crystals,photogenerated electrons tend to transfer to {010} facets while photogenerated holes prefer to accumulate on {120} facets, thus realizing the spatial separation of photogenerated charge between different facets. Morphology tailoring of BiVO_(4) crystals leads to a significantly improved photogenerated charge separation efficiency and photocatalytic water oxidation activity. The built-in electric field for driving the separation of photogenerated electrons and holes is considered to be modulated by tuning the morphology symmetry of BiVO_(4) crystals. This work discloses the significant roles of morphology symmetry in photogenerated charge separation and facilitates the rational design of artificial photocatalysts.
基金National Research Foundation of Korea,Grant/Award Numbers:2021M3H4A1A03057403,2021R1A6A3A03039988,2021R1A6A3A13046700,2021R1A2B5B03001851。
文摘The development of new heterostructures with high photoactivity is a breakthrough for the limitation of solar-driven water splitting.Here,we first introduce indium oxide(In_(2)O_(3))nanorods(NRs)as a novel electron transport layer for bismuth vanadate(BiVO_(4))with a short charge diffusion length.In_(2)O_(3)NRs reinforce the electron transport and hole blocking of BiVO_(4),surpassing the state-of-the-art photoelectrochemical performances of BiVO_(4)-based photoanodes.Also,a tannin-nickel-iron complex(TANF)is used as an oxygen evolution catalyst to speed up the reaction kinetics.The final TANF/BiVO_(4)/In_(2)O_(3)NR photoanode generates photocurrent densities of 7.1 mAcm^(−2) in sulfite oxidation and 4.2 mA cm^(−2) in water oxidation at 1.23 V versus the reversible hydrogen electrode.Furthermore,the“artificial leaf,”which is a tandem cell with a perovskite/silicon solar cell,shows a solar-to-hydrogen conversion efficiency of 6.2%for unbiased solar water splitting.We reveal significant advances in the photoactivity of TANF/BiVO_(4)/In_(2)O_(3)NRs from the tailored nanostructure and band structure for charge dynamics.
基金supported by the National Natural Science Foundation of China (No. 20973017, 21077007)the Creative Research Foundation of Beijing University of Technology (No. 00500054R4003, 005000543111501)+2 种基金the HiTech Research and Development Program (863)of China (No. 2009AA063201)the Funding Projectfor Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality (No. PHR200907105, PHR201007105,PHR201107104)the Hong Kong Baptist University (FRG2/09-10/023)
文摘Monoclinic BiVO4 with multiple morphologies and/or porous structures were fabricated using the hydrothermal strategy. The materials were characterized by means of the XRD, Raman, TGA/DSC, SEM, XPS, and UV-Vis techniques. The photocatalytic activities of the BiVO4 materials were evaluated for the degradation of Methyl Orange under visible-light irradiation. It is observed that pH value and surfactant exerted a great effect on the morphology and pore structure of the BiVO4 product. Spherical BiVO4 with porous structures, flower-cluster-like BiVO4, and flower-bundle-like BiVO4 were generated hydrothermally at 100°C with poly（vinyl pyrrolidone） （PVP） and urea （pH = 2） and at 160°C with NaHCO3 （pH = 7 and 8）, respectively. The PVP-derived BiVO4 showed much higher surface areas （5.0-8.4 m2/g） and narrower bandgap energies （2.45-2.49 eV）. The best photocatalytic performance of the spherical BiVO4 material with a surface area of 8.4 m2/g was associated with its higher surface area, narrower bandgap energy, higher surface oxygen vacancy density, and unique porous architecture.
基金financially supported by the National Natural Science Foundation of China(Nos.21663027,21808189)the Fundamental Research Funds for the Central Universities of Chang’an University(No.300102299304)the Natural Science Basic Research Fund of Shaanxi Province(No.2020JZ20)。
文摘Photoelectrochemical(PEC)technology is considered to be a promising approach for solar-driven hydrogen production with zero emissions.Bismuth vanadate(BiVO_(4))is a kind of photocatalytic material with strong photoactivity in the visible light region and appropriate band gap for PEC water splitting.However,the solar-to-hydrogen efficiency(STH)of BiVO_(4)is far away from the 10%target needed for practical application due to its poor charge separation ability.Therefore,this review attempts to summarize the strategies for improving the photocurrent density and especially hydrogen production of BiVO_(4)materials through PEC techniques in the last three years,such as doping nonmetal and metal elements,depositing noble metals,constructing heterojunctions,coupling with carbon and metalorganic framework(MOF)materials to further enhance the PEC performance of BiVO_(4)photoanode.This review aims to serve as a general guideline to fabricate highly efficient BiVO_(4)-based materials for PEC water splitting.
