Transition-Metal Single Atom Anchored on MoS2 for Enhancing Photocatalytic Hydrogen Production of g-C3N4 Photocatalysts

Single-atom catalyst technology with near-100% atomic utilization and a well-defined coordination structure has provided new ideas for designing high-performance photocatalysts, which is also beneficial for reducing the usage of noble metal cocatalysts. Herein, a series of single-atomic MoS₂-based cocatalysts where monoatomic Ru, Co, or Ni modify MoS₂ (SA-MoS₂) for enhancing the photocatalytic hydrogen production performance of g-C₃N₄ nanosheets (NSs) are rationally designed and synthesized. The 2D SA-MoS₂/g-C₃N₄ photocatalysts with Ru, Co, or Ni single atoms show similar enhanced photocatalytic activity, and the optimized Ru₁-MoS₂/g-C₃N₄ photocatalyst has the highest hydrogen production rate of 11115 μmol/h/g, which is about 37 and 5 times higher than that of pure g-C₃N₄ and MoS₂/g-C₃N₄ photocatalysts, respectively. Experimental and density functional theory calculation results reveal that the enhanced photocatalytic performance is mainly attributed to the synergistic effect and intimate interface between SA-MoS₂ with well-defined coordination single-atomic structures and g-C₃N₄ NSs, which is conducive to the rapid interfacial charge transport, and the unique single-atomic structure of SA-MoS₂ with modified electronic structure and appropriate hydrogen adsorption performance offers abundant reactive sites for enhancing the photocatalytic hydrogen production performance. This work provides new insight into improving the cocatalytic hydrogen production performance of MoS₂ by a single-atomic strategy.