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.
Keywords: 2D structure; g-C3N4; photocatalytic hydrogen production; single atom; transition metal.