A novel p‐n heterostructure photocatalyst m‐Bi2O4/BiOCl was successfully synthetized through a facile ion‐etching method.Via adjusting the added volume of HCl solution,a series of different ratios of composite phot...A novel p‐n heterostructure photocatalyst m‐Bi2O4/BiOCl was successfully synthetized through a facile ion‐etching method.Via adjusting the added volume of HCl solution,a series of different ratios of composite photocatalysts were obtained.The as‐prepared samples of physical,chemical and optical characteristics were examined by X‐ray diffraction,scanning electron microscope,transmission electron microscope,energy dispersive X‐ray spectroscopy,selected‐area electron diffraction,Fourier transform infrared absorption,Raman microscope,N2 adsorption‐desorption,X‐ray photoelectron spectroscopy and UV‐vis spectrum technologies.The photocatalysts showed high degradation rate and complete mineralization ability for methyl orange and tetracycline solution under visible light.The reaction rate constant of m‐Bi2O4/BiOCl for methyl orange was 52.28 times higher than that of BiOCl.The characterization presented a good stability of materials.Furthermore,the photocurrent response test certified that the heterostructure effectively accelerated the separation and migration of photo‐generated carries.The scavenger experiments evidenced that hole(h+)and superoxide radical(?O2?)were the primary active radicals.A possible photocatalytic mechanism was proposed.This work provided an alternative photocatalyst applied to water environmental remediation.展开更多
Constructing Z-scheme heterojunction to improve the separation efficiency of photogenerated carriers of photocatalysts has gained extensive attention.In this work,we fabricated a novel Z-scheme MoO3/Bi2O4 heterojuncti...Constructing Z-scheme heterojunction to improve the separation efficiency of photogenerated carriers of photocatalysts has gained extensive attention.In this work,we fabricated a novel Z-scheme MoO3/Bi2O4 heterojunction photocatalyst by a hydrothermal method.XPS analysis results indicated that strong interaction between MoO3 and Bi2O4 is generated,which contributes to charge transfer and separation of the photogenerated carriers.This was confirmed by photoluminescence(PL)and electrochemical impedance spectroscopy(EIS)tests.The photocatalytic performance of the as-synthesized photocatalysts was evaluated by degrading rhodamine B(RhB)in aqueous solution under visible light irradiation,showing that 15%MoO3/Bi2O4(15-MB)composite exhibited the highest photocatalytic activity,which is 2 times higher than that of Bi2O4.Besides,the heterojunction photocatalyst can keep good photocatalytic activity and stability after five recycles.Trapping experiments demonstrated that the dominant active radicals in photocatalytic reactions are superoxide radical( O2-)and holes(h+),indicating that the 15-MB composite is a Z-scheme photocatalyst.Finally,the mechanism of the Z-scheme MoO3/Bi2O4 composite for photo-degrading RhB in aqueous solution is proposed.This work provides a promising strategy for designing Bi-based Z-scheme heterojunction photocatalysts for highly efficient removal of environmental pollutants.展开更多
基金supported by the National Natural Science Foundation of China(51578354)Suzhou Science and Technology Bureau(SS201667)+1 种基金Six Talent Peaks Program(2016-JNHB-067)Qing Lan Project of Jiangsu Province~~
文摘A novel p‐n heterostructure photocatalyst m‐Bi2O4/BiOCl was successfully synthetized through a facile ion‐etching method.Via adjusting the added volume of HCl solution,a series of different ratios of composite photocatalysts were obtained.The as‐prepared samples of physical,chemical and optical characteristics were examined by X‐ray diffraction,scanning electron microscope,transmission electron microscope,energy dispersive X‐ray spectroscopy,selected‐area electron diffraction,Fourier transform infrared absorption,Raman microscope,N2 adsorption‐desorption,X‐ray photoelectron spectroscopy and UV‐vis spectrum technologies.The photocatalysts showed high degradation rate and complete mineralization ability for methyl orange and tetracycline solution under visible light.The reaction rate constant of m‐Bi2O4/BiOCl for methyl orange was 52.28 times higher than that of BiOCl.The characterization presented a good stability of materials.Furthermore,the photocurrent response test certified that the heterostructure effectively accelerated the separation and migration of photo‐generated carries.The scavenger experiments evidenced that hole(h+)and superoxide radical(?O2?)were the primary active radicals.A possible photocatalytic mechanism was proposed.This work provided an alternative photocatalyst applied to water environmental remediation.
基金supported by the Natural Science Foundation of Hubei Province(2016CFA078)the National Natural Science Foundation of China(51472194)~~
文摘Constructing Z-scheme heterojunction to improve the separation efficiency of photogenerated carriers of photocatalysts has gained extensive attention.In this work,we fabricated a novel Z-scheme MoO3/Bi2O4 heterojunction photocatalyst by a hydrothermal method.XPS analysis results indicated that strong interaction between MoO3 and Bi2O4 is generated,which contributes to charge transfer and separation of the photogenerated carriers.This was confirmed by photoluminescence(PL)and electrochemical impedance spectroscopy(EIS)tests.The photocatalytic performance of the as-synthesized photocatalysts was evaluated by degrading rhodamine B(RhB)in aqueous solution under visible light irradiation,showing that 15%MoO3/Bi2O4(15-MB)composite exhibited the highest photocatalytic activity,which is 2 times higher than that of Bi2O4.Besides,the heterojunction photocatalyst can keep good photocatalytic activity and stability after five recycles.Trapping experiments demonstrated that the dominant active radicals in photocatalytic reactions are superoxide radical( O2-)and holes(h+),indicating that the 15-MB composite is a Z-scheme photocatalyst.Finally,the mechanism of the Z-scheme MoO3/Bi2O4 composite for photo-degrading RhB in aqueous solution is proposed.This work provides a promising strategy for designing Bi-based Z-scheme heterojunction photocatalysts for highly efficient removal of environmental pollutants.
