Photoinduced self-stability mechanism of CdS photocatalyst:The dependence of photocorrosion and H_(2)-evolution performance  

作　　者：Yuxiao Chen Wei Zhong Feng Chen Ping Wang Jiajie Fan Huogen Yu 

机构地区：[1]School of Chemistry,Chemical Engineering and Life Sciences,and State Key Laboratory of Silicate Materials for Architectures,Wuhan University of Technology,Wuhan 430070,China [2]Laboratory of Solar Fuel,Faculty of Materials Science and Chemistry,China University of Geosciences,Wuhan 430070,China [3]School of Materials Science and Engineering,Zhengzhou University,Zhengzhou 450002,China

出　　处：《Journal of Materials Science & Technology》2022年第26期19-27,共9页材料科学技术（英文版）

基　　金：the National Natural Science Foundation of China(Nos.22075220 and 51872221);the 111 Project(No.B18038)。

摘　　要：CdS photocorrosion is one of the most important factors that greatly affect the photocatalytic H_(2)-production rate and long-time stability.However,the reported works about CdS photocorrosion are mainly focused on the surface oxidation by photogenerated holes,while the possible reduction of lattice Cd^(2+) by photogenerated electrons is usually ignored.In this work,the lattice Cd^(2+) reduction by photogenerated electrons during CdS photocorrosion were carefully investigated to reveal its potential effect on the microstructure change and photocatalytic H_(2)-production performance of CdS photocatalyst based on the two typical Na_(2)S-Na_(2)SO_(3) and lactic acid H_(2)-evolution systems.It was found that many isolated metallic Cd nanoparticles(5–50 nm)were produced on the CdS surface in the Na_(2)S-Na_(2)SO_(3) system,causing its serious destroy of CdS surface and a gradually decreased photocatalytic activity,while only a metallic Cd layer(2-3 nm)is homogeneously coated on the CdS surface in the lactic acid system,leading to an increased H-evolution rate.In fact,once a certain amount of metallic Cd was produced on the CdS surface,the resulting CdS-Cd composites can present a stable photocatalytic H_(2)-production activity and excellent stability for the final CdS-Cd photocatalysts.Hence,a photoinduced self-stability mechanism of CdS photocatalyst has been proposed,namely,the spontaneously produced metallic Cd contributes to the transformation of unstable CdS into stable CdS-Cd structure,with the simultaneous realization of final stable H_(2)-evolution performance.

关 键 词：Photocatalysis H_(2)evolution CDS PHOTOCORROSION Self-stability 

分 类 号：TQ116.2[化学工程—无机化工] O643.36[理学—物理化学] O644.1[理学—化学]