Construction of novel noble-metal-free MoP/CdIn2S4 heterojunction photocatalysts: Effective carrier separation, accelerating dynamically H2 release and increased active sites for enhanced photocatalytic H2 evolution.

Abstract

Developing novel photocatalysts with high performance is significant for the practical application of photocatalytic H2 production. Herein, novel and noble-metal-free heterojunction photocatalysts contained CdIn2S4 nanoparticles and bulk MoP were prepared. The H2-production rate of optimal MoP/CdIn2S4 (MPCIS) composites achieved at 286.10μmolg-1h-1, which was nearly 2.2 times that of CdIn2S4-1%Pt (130.51μmolg-1h-1). Electrochemical and PL results displayed that MoP cocatalyst could vastly boost the carrier separation efficiency of CdIn2S4. The high carrier separation efficiency maybe put down to the Fermi level rearrangement between MoP and CdIn2S4. The linear sweep voltammograms tests showed that, compared to CdIn2S4, CdIn2S4 with 30%MoP (30MPCIS) has smaller Tafel slopes and lower H2 evolution overpotentials, which contributed to facilitate H2 release in kinetics. The 30MPCIS composites possess higher Cdl value and MoP has Pt-like electronic structure, so that MoP could offer abundant surface reaction sites of MPCIS composites for HER. Aforementioned results demonstrate that MoP may have great potential in replacing precious metal Pt for photocatalytic H2 production. It is expected that this study can provide new insights into developing the novel sulfide-based heterojunction photocatalysts with MoP as cocatalyst for resultful photocatalytic H2 generation.