Electronic Regulation of Pt Single-Atom Catalysts via Local Coordination State Adjustment for Enhanced Photocatalytic Performance

Single-atom catalysts (SACs) are deemed as the ultimate ceiling route to release the full potential of metal utilization efficiency, while the tougher challenge is to optimize the microstructure for motivating the photocatalytic activity to move forward. Here, Pt SACs with Pt–C2N and Pt–N2 configurations are synthesized by regulating the N vacancy level of ultrathin g-C3N4 (UCN). The distinctive configuration of Pt–C2N and Pt–N2 has been confirmed by X-ray absorption fine spectroscopy. Surprisingly, Pt–C2N displays a satisfactory H2 evolution performance of 112.5 μmol h–1, which is higher than that of Pt–N2 (78.6 μmol h–1). The underlying origins of the discrepancy are investigated by density functional theory (DFT) calculations, which detect that Pt atoms are apt to absorb on C2C to construct strong metal–support interactions. Particularly, owing to the reduced H* desorption energy and a short carrier delivery channel for Pt–C2N, H+ could readily couple with abundant electrons during the hydrogen evolution reaction (HER). Our work points out the future directions for the enhancement of photocatalytic performance by regulating the geometric and electronic structures.