Coupling hydrothermal and photothermal single-atom catalysis toward excellent water splitting to hydrogen

Photocatalytic hydrogen evolution reaction (PER) suffers from deficient solar light efficiency, high cost of noble-metal cocatalysts and low responses to visible and infrared light. In this article, we report single-atom silver incorporated g-C3N4 (SAAg-g-CN) as a low-cost and stable catalyst with higher activities in PER and solar-heat-assisted PER processes than Ag nanoparticle decorated g-C3N4 (AgNP-g-CN) and PtNP-g-C3N4. The excellent activity of SAAg-g-CN is benefited from the proper Gibbs free energy of the adsorbed hydrogen atom (ΔGH*) and robust structure of N-Ag bonding of the SAAg-g-CN. The PER rate of SAAg-g-CN at 55 °C was doubled as compared to that at 25 °C, meanwhile, AgNP-g-CN and PtNP-g-CN showed descending PER performances, due to the agglomeration of metal NPs. This work demonstrates the ultrahigh photoactivity and photothermal stability of SAAg-g-CN, and its potential in facilitating the full exploitation of solar energy.