Dual-synergistic molybdenum disulfide and molybdenum carbide cocatalyst integrated with graphitic carbon nitride for efficient photocatalytic hydrogen production

Heterojunctions have garnered significant attention in the field of photocatalysis due to their exceptional ability to facilitate the separation of photogenerated charge carriers and their high efficiency in hydrogen reaction. However, their overall photocatalytic performance is often constrained by electron transport rates and suboptimal hydrogen adsorption/desorption kinetics. To address these challenges, this study develops a g-C₃N₄/MoS₂@Mo₂C dual-effect synergistic solid-state Z-type heterojunction, synthesized through the in-situ sulfurization of Mo₂C combined with ultrasonic self-assembly technique. Under simulated sunlight, g-C₃N₄/MoS₂@Mo₂C achieved a stable photocatalytic hydrogen production rate of 3.44 mmol g^-1 h^-1, which is 688 times, 6.02 times, and 1.48 times higher than g-C₃N₄, g-C₃N₄/MoS₂ and g-C₃N₄/Mo₂C, respectively. Experimental characterization and theoretical calculations indicate that Mo₂C functions as an electron transport bridge, effectively reducing charge separation resistance. Additionally, the MoS₂@Mo₂C composite co-catalyst exhibits a Gibbs free energy of hydrogen adsorption closer to zero than Mo₂C and MoS₂, thereby enhancing the binding of photogenerated electrons and protons and facilitating efficient hydrogen production. This research presents a novel design strategy for high-performance photocatalysts, contributing to the advancement of solar-driven hydrogen production technology.