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.

Keywords

• Molybdenum carbide
• Photo-thermal conversion
• H2 evolution
• Schottky junction