Asymmetric coordination enhances the synergy of Pt species dual active sites for efficient photocatalytic H2 evolution

Integrating distinct functional reaction sites within a single photocatalyst offers a promising approach for enhancing the photocatalytic H2 evolution by water splitting. However, the synergy between the dual active sites is hindered by suboptimal electronic states arising from the uniform coordination environments. Here we demonstrate a strategy for enhancing the synergy between Pt single atoms and nanoparticles by modulating the coordination environment. The optimal boron doped catalyst with B-Pt-O asymmetric coordination achieves a H2 evolution rate of 627.6 mmol g-1h-1, with an apparent quantum efficiency of 98.4%. Experimental and theoretical analysis reveal that the asymmetric coordination structure redistributes the electron density of Pt cocatalysts, promoting charge carrier separation, optimizing the dissociation and adsorption-desorption of the intermediate H2O* and H* on the dual sites. The findings highlight the importance of asymmetric coordination facilitates the photogenerated carrier transfer and surface reactions for efficient photocatalytic H2 evolution.