Preparation of Feather-like Bi2S3/Bi2O3 Heterojunctions and Their Photocatalytic Reduction Performance for Cr(Ⅵ)
Heterojunction building can effectively promote the separation and transfer of electron-hole pair,prolong the lifetime of charge carriers,and enhance the performance of photocatalysts.In this paper,feather-like Bi2S3/Bi2O3(BSO)heterojunctions were synthesized by in situ hydrothermal method using L-cysteine as a template agent.The effects of template agent dosage and solution pH on the performance of photocatalytic reduction of hexavalent chromium(Cr(Ⅵ))were investigated,and the photocatalytic mechanism was explored by reactive radicals trapping experiments and photoelectrochemical characterization.The results show that the reduction rate of Cr(Ⅵ)reaches 98.69％after 4 h of visible light irradiation at a molar ratio of Bi atoms to cysteine of 1∶1 and a solution pH of 2,which is 54.55 and 32.04 times higher than that of pure Bi2O3 and Bi2S3,respectively.The high photocatalytic activity is attributed to the high specific surface area,effective visible light response and the formation of Bi2S3/Bi2O3 heterojunction,and the built-in electric field generation at the interface can provide a pathway for the effective separation of photogenerated electrons and holes.
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