Porous CuS/ZnS microspheres derived from a bimetallic metal-organic framework as efficient photocatalysts for H2 production

Abstract

In this work, porous CuS/ZnS microspheres have been successfully fabricated through a facile metal-organic framework (MOF) derived route. The preparation process involved a solvothermal method for synthesis of bimetallic MOF (Cu-Zn-MOF) and subsequently vulcanization treatment to transform into CuS/ZnS microspheres. The MOF-derived CuS/ZnS microspheres inherited the porous skeleton of the Cu-Zn-MOF precursor, which significantly enhanced the utilization of light and synchronously provided plentiful exposed catalytic active sites. The obtained CuS/ZnS microspheres exhibited excellent photocatalytic activity for hydrogen production via water splitting. The optimized CuS/ZnS photocatalyst demonstrated a H2-production rate of 310.43 μmol h−1 under visible light with an apparent quantum efficiency of 8.5% at 420 nm. Such excellent photocatalytic H2-evolution activity was ascribed to the interfacial charge transfer from the valence band of ZnS to CuS, which facilitated the efficient electron-hole separation and transportation. This study provides a strategy for the rational design of MOF-derived photocatalysts to dramatically increase H2 production efficiency.