Conductive Co1.5MoS3.2 promoted photocatalytic H2 production over g-C3N4.

Abstract

In this work, Co1.5MoS3.2 (CMS) nanoparticles were synthesized using a one-step hydrothermal approach, series CMS/g-C3N4 photocatalysts with various CMS amount were obtained using a physical solvent evaporation method. The investigation indicates that introducing CMS as cocatalysts can greatly enhance the H2 production activity of g-C3N4 by two orders of magnitude. The H2 production rate reaches up to 17607 μmol·g−1·h−1 over 40 wt% CMS/g-C3N4, resulting in a 185-fold increase when compared to the unmodified g-C3N4 (94.8 μmol·g−1·h−1), far better than 40 wt% MoS2/g-C3N4 (125.2 μmol·g−1·h−1), 40 wt% Co3S4/g-C3N4 (7948.6 μmol·g−1·h−1), even widely 3 wt% Pt/g-C3N4 (12803 μmol·g−1·h−1). The improvement can be ascribed to the Schottky junction effect between CMS and g-C3N4, the highly conductive CMS can receive electrons from the conduction band of g-C3N4, preventing charge recombination. Meanwhile, CMS can obviously lower the H2 evolution potential and provide more active site for the H2 evolution reaction, those all lead to a faster H2 evolution kinetics. Additionally, CMS as a cocatalyst offers advantages such as simple preparation, low cost, and remarkable effectiveness, making it highly promising for further development.