摘要
The g-C_(3)N_(4)/BiOI/CdS double Z-scheme heterojunction photocatalyst with I_(3)^(-)/I^(-) redox pairs is prepared using simple calcination,solvothermal,and solution chemical deposition methods.The photocatalyst comprised mesoporous,thin g-C_(3)N_(4) nanosheets loaded on flower-like microspheres of BiOI with CdS quantum dots.The g-C_(3)N_(4)/BiOI/CdS double Z-scheme heterojunction has abundant active sites and in situ redox I_(3)^(-)/I^(-) mediators and shows quantum size effects,which are all conducive to enhancing the separation of photoinduced charges and increasing the photocatalytic degradation efficiency for bisphenol A,a model pollutant.Specifically,the heterojunction photocatalyst achieves a photocatalytic degradation efficiency for bisphenol A of 98.62%in 120 min and photocatalytic hydrogen production of 863.44 mmol h^(-1) g^(-1) on exposure to visible light.The excellent visible-light photocatalytic performance is as a result of the Z-scheme heterojunction,which extends absorption to the visible light region,as well as the I_(3)^(-)/I^(-) pairs,which accelerate photoinduced charge carrier transfer and separation,thus dramatically boosting the photocatalytic performance.In addition,the key role of the charge transfer across the indirect Z-scheme heterojunction has been elucidated and the transfer mechanism is confirmed based on the detection of intermediate I_(3)^(-)ions.Thus,this study provides guidelines for the design of indirect Z-scheme heterojunction photocatalysts.
基金
support of this work by the National Natural Science Foundation of China(51869006)
Jiangxi Natural Science Foundation of China(20171BAB216050)
Water Science and Technology Fund of Jiangxi Province in China(KT201702).
