Visible light photocatalytic H_2-production activity of CuS/ZnS porous nanosheets based on photoinduced interfacial charge transfer

摘要

Visible light photocatalytic H_2 production through water splitting is of great importance for its potential application in converting solar energy into chemical energy. In this study, a novel visible-light-driven photocatalyst was designed based on photoinduced interfacial charge transfer (IFCT) through surface modification of ZnS porous nanosheets by CuS. CuS/ZnS porous nanosheet photocatalysts were prepared by a simple hydrothermal and cation exchange reaction between preformed ZnS(en)_(0.5) nanosheets and Cu(NO_3)_2. Even without a Pt cocatalyst, the as-prepared CuS/ZnS porous nanosheets reach a high H_2-production rate of 4147 μmol h~(-1) g~(-1) at CuS loading content of 2 mol % and an apparent quantum efficiency of 20% at 420 nm. This high visible light photocatalytic H_2-production activity is due to the IFCT from the valence band of ZnS to CuS, which causes the reduction of partial CuS to Cu _2S and thus enhances H_2-production activity. This work not only shows a possibility for substituting low-cost CuS for noble metals in the photocatalytic H_2 production but also for the first time exhibits a facile method for enhancing H_2-production activity by photoinduced IFCT.