Fabrication of novel and noble-metal-free MoP/In2S3 Schottky heterojunction photocatalyst with efficient charge separation for enhanced photocatalytic H2 evolution under visible light

Abstract

Here, we synthesized a series of noble-metal-free MoP/In2S3 Schottky heterojunction photocatalysts through two-step synthesis. Morphology characterization revealed that In2S3 was deposited on metal-like MoP. The electrochemical experiment, photoluminescence (PL) and time-resolved transient PL results verify that electron-hole pairs separation efficiency of MoP-In2S3 composites has been immensely elevated compared to pristine In2S3. The effective separation of photocarriers is attributed to the appropriate Schottky energy barrier, band bending and Fermi level rearrangement between MoP and In2S3. Furthermore, the X-ray photoelectron spectra confirmed that electrons transferred from In2S3 to MoP in Schottky heterojunction. Importantly, MoP possesses active sites for H2 generation resulting from nearly zero binding for H atoms and low onset overpotentials. As expected, the 25 %MoP-In2S3 composites exhibited excellent photocatalytic activity (481.73 μmol·h−1·g−1), which was about 23 times than In2S3-1 %Pt (20.73 μmol·h−1·g−1). Hence, the enhanced photocatalytic performance was ascribed to not only the formed Schottky heterojunction leading to better charge separation, but also MoP as the active sites accelerated the surface proton reduction reaction. The research furnishes a thought that suitable semiconductors and metal-like were selected to construct high performance and low-cost Schottky heterojunction with efficient charge separation and active sites for resultful photocatalytic H2 generation.