Novel TiO2/BiVO4 microfiber heterojunctions were constructed using cotton as biomorphic templates. The as-synthesized samples were characterized by scanning electron microscope, X-ray diffraction, X-ray photoelectron ...Novel TiO2/BiVO4 microfiber heterojunctions were constructed using cotton as biomorphic templates. The as-synthesized samples were characterized by scanning electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy, UV-Vis diffuse reflectance spectra and photocatalytic experiment. The morphology of the as-synthesized TiO2/BiVO4 composites was consisted of a large quantity of microfiber structures with diameter from 2.5 gm to 5 μm, and the surface of samples became more coarse and compact with the increase of weight ratio of TiO2. The TiO2/BiVO4 samples with proper content （10.00wt%） showed the highest pho- tocatalytic degradation activity for methylene blue （MB） degradation among all the samples under visible light, and 88.58%MB could be degraded within 150 min. The enhancement of photocatalytic activity was mainly attributed to the formation of n-n heterojunction at the contact interface of TiO2 and BiVO4, which not only narrowed the band gap of BiVO4 for extending the absorption range of visible light, but also promoted the transfer of charge carriers across interface. A possible photodegradation mechanism of MB in the presence of TiO2/BiVO4 microfibrous photocatalyst was proposed.展开更多
Herein,perylenetetracarboxylic acid(PTA)nanosheets with anisotropic charge migration driven by the formed internal electric fields are synthesized through a facile hydrolysis-reassembly process.Strategically,a Z-schem...Herein,perylenetetracarboxylic acid(PTA)nanosheets with anisotropic charge migration driven by the formed internal electric fields are synthesized through a facile hydrolysis-reassembly process.Strategically,a Z-scheme heterojunction with free-flowing interfacial charge transfer and spatially separated redox centers is constructed based on the distinct photogenerated electrons and holes accumulation regions of PTA nanosheets by in-situ introducing BiVO_(4)quantum dots(BQD)and nanosized Au.The optimized BQD/PTA-Au exhibits a ca.6.4-fold and 4.8-fold enhancement in H_(2)O_(2)production rate and apparent quantum yield at 405 nm compared with pristine PTA,respectively.The exceptional activities are attributed to the cascade Z-scheme charge transfer followed the matched charge migration orientation,as well as the Au active sites for accelerating 2e-oxygen reduction pathway induced by superoxide radicals,as unraveled by electron paramagnetic resonance,in-situ irradiated X-ray photoelectron spectroscopy and in-situ diffuse reflectance infrared Fourier transformation spectroscopy.This work provides a strategy to design an efficient Z-scheme system towards solar-driven H_(2)O_(2)production.展开更多
We report the development of a novel visible response BiVO_4/TiO_2(N_2) nanotubes photoanode for photoelectrocatalytic applications. The nitrogen-treated TiO_2 nanotube shows a high carrier concentration rate, thus re...We report the development of a novel visible response BiVO_4/TiO_2(N_2) nanotubes photoanode for photoelectrocatalytic applications. The nitrogen-treated TiO_2 nanotube shows a high carrier concentration rate, thus resulting in a high efficient charge transportation and low electron–hole recombination in the TiO_2–BiVO_4. Therefore, the BiVO_4/TiO_2(N_2) NTs photoanode enabled with a significantly enhanced photocurrent of 2.73 mA cm^(-2)(at 1 V vs. Ag/Ag Cl) and a degradation efficiency in the oxidation of dyes under visible light. Field emission scanning electron microscopy, X-ray diffractometry, energy-dispersive X-ray spectrometer, and UV–Vis absorption spectrum were conducted to characterize the photoanode and demonstrated the presence of both metal oxides as a junction composite.展开更多
In this work,samples consisting of BiVO4 with exposed(040)facets coupled with Bi2S3(Bi2S3/BiVO4)were prepared through a one-pot hydrothermal method,using ethylenediaminetetraacetic acid as directing agent and L-cystei...In this work,samples consisting of BiVO4 with exposed(040)facets coupled with Bi2S3(Bi2S3/BiVO4)were prepared through a one-pot hydrothermal method,using ethylenediaminetetraacetic acid as directing agent and L-cysteine as sulfur source and soft template.X-ray diffraction,field emission scanning electron microscopy,and high-resolution transmission electron microscopy measurements indicated that the Bi2S3 content had a significant influence on the growth of(040)and(121)facets as well as on the morphology of the Bi2S3/BiVO4 samples.When the Bi2S3 content reached 1 mmol,the Bi2S3/BiVO4 samples exhibited a peony-like morphology.The results of transient photocurrent tests and electrochemical impedance spectroscopy measurements confirmed that a more effective charge separation and a faster interfacial charge transfer occurred in Bi2S3/BiVO4 than BiVO4.The enhanced photocatalytic activity of the Bi2S3/BiVO4 samples could be attributed to the improved absorption capability in the visible light region and the enhanced electron-hole pair separation efficiency due to the formation of the Bi2S3/BiVO4 heterostructure.In addition,the Bi2S3/BiVO4 samples showed relative stability and reusability.The simple method presented in this work could be used to fabricate composite photocatalysts with high activity for different applications,such as photocatalytic degradation of organic pollutants,photocatalytic splitting of water,and photocatalytic reduction of carbon dioxide.展开更多
Constructing a Z-scheme is a significant approach to improve the separation of photogene rated carriers for effective organic pollutant degradation.Herein,a BiVO4/ZnIn2S4(BZ) Z-scheme composite was successfully synthe...Constructing a Z-scheme is a significant approach to improve the separation of photogene rated carriers for effective organic pollutant degradation.Herein,a BiVO4/ZnIn2S4(BZ) Z-scheme composite was successfully synthesized,and applied to photodegrade methyl orange(MO) irradiated by a LED lamp.Anchoring the BiVO4 on the ZnIn2S4 nanoparticles promoted the separation of photogenerated electronholes and broadened the light response range.The detailed characterizations,including surface morphology,elements valence state,and photocurrent performance,demonstrated that the enhanced separation of photogenerated carriers was the pivotal reason for the enhanced photocatalysis reaction.Benefiting from the excellent photocatalytic characteristics,the 5% mass ratio of BZ composite presented the highest MO degradation rate of 0.00997 min^-1,which was 1.9 and 10.3 times greater than the virgin ZnIn2S4 and BiVO4,respectively.Furthermore,the BZ hybrid materials indicated a well photo-stability in the four recycling tests.展开更多
The construction of S‐scheme heterojunction photocatalysts has been regarded as an effective avenue to facilitate the conversion of solar energy to fuel.However,there are still considerable challenges with regard to ...The construction of S‐scheme heterojunction photocatalysts has been regarded as an effective avenue to facilitate the conversion of solar energy to fuel.However,there are still considerable challenges with regard to efficient charge transfer,the abundance of catalytic sites,and extended light absorption.Herein,an S‐scheme heterojunction of 2D/2D zinc porphyrin‐based metal‐organic frameworks/BiVO_(4)nanosheets(Zn‐MOF/BVON)was fabricated for efficient photocatalytic CO_(2)conversion.The optimal one shows a 22‐fold photoactivity enhancement when compared to the previously reported BiVO4 nanoflake(ca.15 nm),and even exhibits~2‐time improvement than the traditional g‐C3N4/BiVO4 heterojunction.The excellent photoactivities are ascribed to the strengthened S‐scheme charge transfer and separation,promoted CO_(2)activation by the well‐dispersed metal nodes Zn_(2)(COO)_(4)in the Zn‐MOF,and extended visible light response range based on the results of the electrochemical reduction,electron paramagnetic resonance,and in‐situ diffuse reflectance infrared Fourier transform spectroscopy.The dimension‐matched Zn‐MOF/BVON S‐scheme heterojunction endowed with highly efficient charge separation and abundant catalytic active sites contributed to the superior CO2 conversion.This study offers a facile strategy for constructing S‐scheme heterojunctions involving porphyrin‐based MOFs for solar fuel production.展开更多
A series of SO 2- 4/TiO 2 SiO 2 catalysts with different mass fractions of SiO 2 were prepared by sol gel method. The effect of adding SiO 2 on the crystal structure, specific surface area, oxygen adsorption, and acid...A series of SO 2- 4/TiO 2 SiO 2 catalysts with different mass fractions of SiO 2 were prepared by sol gel method. The effect of adding SiO 2 on the crystal structure, specific surface area, oxygen adsorption, and acidity of SO 2- 4/TiO 2 catalyst and its photocatalytic property for degradation of bromomethane was studied. The results showed that the specific surface area and amount of oxygen adsorption of catalyst were increased by addition of SiO 2, leading to the obvious increase on photocatalytic activity of SO 2- 4/TiO 2 SiO 2 catalysts and mineralization ratio of bromomethane. Comparing with SO 2- 4/TiO 2, the acidic strength and anti moisture ability of SO 2- 4/TiO 2 SiO 2 catalyst were decreased.展开更多
基金This work was supported by Program Funded by Sha.anxi Department （No.2013JK0690）, the Scientific Research Provincial Education Fundamental Research Funds of Xianyang Normal University （No. 14XSYK011, No.12XSYK025）, Shaanxi Province Natural Science Foundation （No.2015JQ5188）.
文摘Novel TiO2/BiVO4 microfiber heterojunctions were constructed using cotton as biomorphic templates. The as-synthesized samples were characterized by scanning electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy, UV-Vis diffuse reflectance spectra and photocatalytic experiment. The morphology of the as-synthesized TiO2/BiVO4 composites was consisted of a large quantity of microfiber structures with diameter from 2.5 gm to 5 μm, and the surface of samples became more coarse and compact with the increase of weight ratio of TiO2. The TiO2/BiVO4 samples with proper content （10.00wt%） showed the highest pho- tocatalytic degradation activity for methylene blue （MB） degradation among all the samples under visible light, and 88.58%MB could be degraded within 150 min. The enhancement of photocatalytic activity was mainly attributed to the formation of n-n heterojunction at the contact interface of TiO2 and BiVO4, which not only narrowed the band gap of BiVO4 for extending the absorption range of visible light, but also promoted the transfer of charge carriers across interface. A possible photodegradation mechanism of MB in the presence of TiO2/BiVO4 microfibrous photocatalyst was proposed.
文摘Herein,perylenetetracarboxylic acid(PTA)nanosheets with anisotropic charge migration driven by the formed internal electric fields are synthesized through a facile hydrolysis-reassembly process.Strategically,a Z-scheme heterojunction with free-flowing interfacial charge transfer and spatially separated redox centers is constructed based on the distinct photogenerated electrons and holes accumulation regions of PTA nanosheets by in-situ introducing BiVO_(4)quantum dots(BQD)and nanosized Au.The optimized BQD/PTA-Au exhibits a ca.6.4-fold and 4.8-fold enhancement in H_(2)O_(2)production rate and apparent quantum yield at 405 nm compared with pristine PTA,respectively.The exceptional activities are attributed to the cascade Z-scheme charge transfer followed the matched charge migration orientation,as well as the Au active sites for accelerating 2e-oxygen reduction pathway induced by superoxide radicals,as unraveled by electron paramagnetic resonance,in-situ irradiated X-ray photoelectron spectroscopy and in-situ diffuse reflectance infrared Fourier transformation spectroscopy.This work provides a strategy to design an efficient Z-scheme system towards solar-driven H_(2)O_(2)production.
基金the National Nature Science Foundation of China(21507085,21576162)Shanghai Sailing Program of China(14YF1401500)for financial support
文摘We report the development of a novel visible response BiVO_4/TiO_2(N_2) nanotubes photoanode for photoelectrocatalytic applications. The nitrogen-treated TiO_2 nanotube shows a high carrier concentration rate, thus resulting in a high efficient charge transportation and low electron–hole recombination in the TiO_2–BiVO_4. Therefore, the BiVO_4/TiO_2(N_2) NTs photoanode enabled with a significantly enhanced photocurrent of 2.73 mA cm^(-2)(at 1 V vs. Ag/Ag Cl) and a degradation efficiency in the oxidation of dyes under visible light. Field emission scanning electron microscopy, X-ray diffractometry, energy-dispersive X-ray spectrometer, and UV–Vis absorption spectrum were conducted to characterize the photoanode and demonstrated the presence of both metal oxides as a junction composite.
文摘In this work,samples consisting of BiVO4 with exposed(040)facets coupled with Bi2S3(Bi2S3/BiVO4)were prepared through a one-pot hydrothermal method,using ethylenediaminetetraacetic acid as directing agent and L-cysteine as sulfur source and soft template.X-ray diffraction,field emission scanning electron microscopy,and high-resolution transmission electron microscopy measurements indicated that the Bi2S3 content had a significant influence on the growth of(040)and(121)facets as well as on the morphology of the Bi2S3/BiVO4 samples.When the Bi2S3 content reached 1 mmol,the Bi2S3/BiVO4 samples exhibited a peony-like morphology.The results of transient photocurrent tests and electrochemical impedance spectroscopy measurements confirmed that a more effective charge separation and a faster interfacial charge transfer occurred in Bi2S3/BiVO4 than BiVO4.The enhanced photocatalytic activity of the Bi2S3/BiVO4 samples could be attributed to the improved absorption capability in the visible light region and the enhanced electron-hole pair separation efficiency due to the formation of the Bi2S3/BiVO4 heterostructure.In addition,the Bi2S3/BiVO4 samples showed relative stability and reusability.The simple method presented in this work could be used to fabricate composite photocatalysts with high activity for different applications,such as photocatalytic degradation of organic pollutants,photocatalytic splitting of water,and photocatalytic reduction of carbon dioxide.
基金financial supports from the National Natural Science Foundation of China(Nos.51908485 and 51608468)the China Postdoctoral Science Foundation(No.2019T120194)the University Science and Technology Program Project of Hebei Provincial Department of Education(No.QN2018258)。
文摘Constructing a Z-scheme is a significant approach to improve the separation of photogene rated carriers for effective organic pollutant degradation.Herein,a BiVO4/ZnIn2S4(BZ) Z-scheme composite was successfully synthesized,and applied to photodegrade methyl orange(MO) irradiated by a LED lamp.Anchoring the BiVO4 on the ZnIn2S4 nanoparticles promoted the separation of photogenerated electronholes and broadened the light response range.The detailed characterizations,including surface morphology,elements valence state,and photocurrent performance,demonstrated that the enhanced separation of photogenerated carriers was the pivotal reason for the enhanced photocatalysis reaction.Benefiting from the excellent photocatalytic characteristics,the 5% mass ratio of BZ composite presented the highest MO degradation rate of 0.00997 min^-1,which was 1.9 and 10.3 times greater than the virgin ZnIn2S4 and BiVO4,respectively.Furthermore,the BZ hybrid materials indicated a well photo-stability in the four recycling tests.
文摘The construction of S‐scheme heterojunction photocatalysts has been regarded as an effective avenue to facilitate the conversion of solar energy to fuel.However,there are still considerable challenges with regard to efficient charge transfer,the abundance of catalytic sites,and extended light absorption.Herein,an S‐scheme heterojunction of 2D/2D zinc porphyrin‐based metal‐organic frameworks/BiVO_(4)nanosheets(Zn‐MOF/BVON)was fabricated for efficient photocatalytic CO_(2)conversion.The optimal one shows a 22‐fold photoactivity enhancement when compared to the previously reported BiVO4 nanoflake(ca.15 nm),and even exhibits~2‐time improvement than the traditional g‐C3N4/BiVO4 heterojunction.The excellent photoactivities are ascribed to the strengthened S‐scheme charge transfer and separation,promoted CO_(2)activation by the well‐dispersed metal nodes Zn_(2)(COO)_(4)in the Zn‐MOF,and extended visible light response range based on the results of the electrochemical reduction,electron paramagnetic resonance,and in‐situ diffuse reflectance infrared Fourier transform spectroscopy.The dimension‐matched Zn‐MOF/BVON S‐scheme heterojunction endowed with highly efficient charge separation and abundant catalytic active sites contributed to the superior CO2 conversion.This study offers a facile strategy for constructing S‐scheme heterojunctions involving porphyrin‐based MOFs for solar fuel production.
文摘A series of SO 2- 4/TiO 2 SiO 2 catalysts with different mass fractions of SiO 2 were prepared by sol gel method. The effect of adding SiO 2 on the crystal structure, specific surface area, oxygen adsorption, and acidity of SO 2- 4/TiO 2 catalyst and its photocatalytic property for degradation of bromomethane was studied. The results showed that the specific surface area and amount of oxygen adsorption of catalyst were increased by addition of SiO 2, leading to the obvious increase on photocatalytic activity of SO 2- 4/TiO 2 SiO 2 catalysts and mineralization ratio of bromomethane. Comparing with SO 2- 4/TiO 2, the acidic strength and anti moisture ability of SO 2- 4/TiO 2 SiO 2 catalyst were decreased.
