Construction of Mo/Mo2C@C modified ZnIn2S4 Schottky junctions for efficient photo-thermal assisted hydrogen evolution

Abstract

Photocatalytic water splitting on noble metal-free photocatalysts for H₂ generation is a promising but challenging approach to realize solar-to-chemical energy conversion. In this study, Mo/Mo₂C nanoparticles anchored carbon layer (Mo/Mo₂C@C) was obtained by a one-step in-situ phase transition approach and developed for the first time as a photothermal cocatalyst to enhance the activity of ZnIn₂S₄ photocatalyst. Mo/Mo₂C@C nanosheet exhibits strong absorption in the full spectrum region and excellent photo-thermal conversion ability, which generates heat to improve the reaction temperature and accelerate the reaction kinetics. Moreover, metallic Mo/Mo₂C@C couples with ZnIn₂S₄ to form ZnIn₂S₄–Mo/Mo₂C@C Schottky junction (denoted as ZMM), which prevents the electrons back transfer and restrains the charge recombination. In addition, conductive carbon with strong interfacial interaction serves as a fast charge transport bridge. Consequently, the optimized ZMM-0.2 junction exhibits an H₂ evolution rate of 1031.07 μmol g⁻¹ h⁻¹, which is 41 and 4.3 times higher than bare ZnIn₂S₄ and ZnIn₂S₄–Mo₂C, respectively. By designing novel photothermal cocatalysts, our work will provide a new guidance for designing efficient photocatalysts.