Ordered mesoporous MoC and Pt-MoC as co-catalysts for photocatalytic hydrogen production

Slow reaction kinetics intrinsically limits the efficiency of semiconductor-based photocatalytic hydrogen generation and suitable cocatalysts are highly desired. Molybdenum carbide (MoC) is viewed as a promising Pt-like catalyst or support for hydrogen evolution reaction but usually suffers from low active surface area in traditional high-temperature carburization. Herein, we present an ordered mesoporous MoC featuring both large mesopores (11 nm) and ultrathin frameworks (∼5 nm), which provide a substantial surface area (108 m²·g⁻¹) for loading Pt co-catalysts and constructing an efficient heterostructure in combination with ultrathin ZnIn₂S₄ (ZIS) nanosheets. The resultant Pt-MoC@ZIS heterostructure showed a significantly improved hydrogen evolution (0.357 mmol·h⁻¹) with an apparent quantum efficiency (AQE) of 85.9% at 395 nm and decreased Pt dose (0.11 wt%) over the directly Pt-loaded ZIS, which should be attributed to the enhanced mass activity of Pt well-dispersed on conductive MoC frameworks for facilizing surface reaction, boosted carrier separation and reduced ZIS aggregation from the heterostructure for inhibiting bulk and surface recombination. This study may offer valuable insights for developing efficient low Pt or even Pt-free photocatalysts.