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

Single-atom catalysts (SACs) are deemed as the ultimateceilingroute to release the full potential of metal utilization efficiency,while the tougher challenge is to optimize the microstructure formotivating the photocatalytic activity to move forward. Here, Pt SACswith Pt-C2N and Pt-N-2 configurationsare synthesized by regulating the N vacancy level of ultrathin g-C3N4 (UCN). The distinctive configuration of Pt-C2N and Pt-N-2 has been confirmed by X-rayabsorption fine spectroscopy. Surprisingly, Pt-C2N displays a satisfactory H-2 evolution performance of112.5 mu mol h(-1), which is higher than thatof Pt-N-2 (78.6 mu mol h(-1)).The underlying origins of the discrepancy are investigated by densityfunctional theory (DFT) calculations, which detect that Pt atoms areapt to absorb on C-2C to construct strong metal-supportinteractions. Particularly, owing to the reduced H* desorption energyand a short carrier delivery channel for Pt-C2N,H+ could readily couple with abundant electrons duringthe hydrogen evolution reaction (HER). Our work points out the futuredirections for the enhancement of photocatalytic performance by regulatingthe geometric and electronic structures.

Automated summary

Single-atom catalysts (SACs) are considered as the ultimate route to improve metal utilization efficiency. In this study, Pt SACs with Pt-C2N and Pt-N-2 configurations were synthesized by regulating the N vacancy level of ultrathin g-C3N4 (UCN). The distinctive configuration of Pt-C2N and Pt-N-2 was confirmed through X-ray absorption fine spectroscopy. Pt-C2N exhibited a higher H-2 evolution performance (112.5 mu mol h(-1)) compared to Pt-N-2 (78.6 mu mol h(-1)). Density functional theory (DFT) calculations revealed that Pt atoms tend to absorb on C-2C and construct strong metal-support interactions.