Screening of red phosphorus supported transition metal single-atom catalysts for efficient photocatalytic water splitting H2 generation†

Abstract

Red phosphorus (RP) supported transition-metal (TM) single-atom catalysts (SACs) are potential catalysts for photocatalytic H₂ evolution. However, efficient screening and in-depth explorations are still needed. In this work, comprehensive density functional theory (DFT) calculations have been performed to reveal the electronic and surface adsorption properties of these TM-RP SACs to predict their photocatalytic activity and reaction mechanisms. The adsorption of proton and H₂O at the active catalytic sites has been calculated and further analyzed by combination with Mulliken charge results, which are greatly affected by the structural stability of the catalytic surface and the interactions between SA-TMs and supporting RP. To reveal the thermodynamic reaction trends of both hydrogen and oxygen evolution reactions, the band alignments for pristine-RP and twenty-nine TM-RP candidates have been demonstrated with reference to the redox potentials of water at different pH values. The modulations in electronic structure induced by H₂O adsorption have also been studied. Through systematic exploration, we have identified that Fe-RP, Co-RP, Ni-RP, and Nb-RP are promising candidates as photocatalysts for hydrogen evolution. This work supplies significant insights into the screening of novel SACs for photocatalysis.