Synergistic effect of electron and proton pumps Pt single-atom catalyst: dual mechanisms to boost photocatalytic hydrogen production

Effective proton-coupled electron transfer is crucial in photocatalytic hydrogen evolution reaction (HER) but is impeded by the sluggish H 2 O dissociation and photogenerated carrier recombination. Here, dual-ion doping is used to construct electron pumps and proton pumps in Pt SA /TiO 2 single-atom catalyst to enhance hydrogen proton (H∗) migration and electron transfer at the same time. The optimum photocatalyst (BPt SA /TiO 2 (Pr)) exhibits an excellent H 2 evolution rate of 259.11 mmol g −1 h −1 , which is approximately 1.3 times higher than that of Pt SA /TiO 2 (Pr) (196.43 mmol g −1 h −1 ). Combined with in situ characterization and theoretical calculations, the roles of B and Pr are unveiled. B doping promotes H 2 O adsorption and dissociation to generate efficient H∗, while Pr doping drives directional electron transfer to the Pt atom through the Pr-O-Pt unit, and electron-enriched Pt single atoms enable fast H∗ trapping and hydrogen evolution. The unique dual-pump configuration concurrently modulates mass-migration dynamics and photogenerated carrier transfer kinetics. This work offers a promising approach for the precise design of photocatalysts with a controlled coordination environment, simultaneously providing a comprehensive understanding of the HER catalytic mechanism.