Visible Light Photocatalytic H2-Production Activity of CuS/ZnS Porous Nanosheets Based on Photoinduced Interfacial Charge Transfer

Abstract

Visible light photocatalytic H₂ 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(NO₃)₂. Even without a Pt cocatalyst, the as-prepared CuS/ZnS porous nanosheets reach a high H₂-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 H₂-production activity is due to the IFCT from the valence band of ZnS to CuS, which causes the reduction of partial CuS to Cu₂S and thus enhances H₂-production activity. This work not only shows a possibility for substituting low-cost CuS for noble metals in the photocatalytic H₂ production but also for the first time exhibits a facile method for enhancing H₂-production activity by photoinduced IFCT.