Transition-Metal Single Atom Anchored on MoS for Enhancing Photocatalytic Hydrogen Production of g-CN 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 MoS-based cocatalysts where monoatomic Ru, Co, or Ni modify MoS (SA-MoS) for enhancing the photocatalytic hydrogen production performance of g-CN nanosheets (NSs) are rationally designed and synthesized. The 2D SA-MoS/g-CN photocatalysts with Ru, Co, or Ni single atoms show similar enhanced photocatalytic activity, and the optimized Ru-MoS/g-CN 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-CN and MoS/g-CN 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-MoS with well-defined coordination single-atomic structures and g-CN NSs, which is conducive to the rapid interfacial charge transport, and the unique single-atomic structure of SA-MoS 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 MoS by a single-atomic strategy.