Enhanced Electron-Hole Separation in Phosphorus-Coordinated Co Atom on g-C₃N₄ toward Photocatalytic Overall Water...

Revealing the decoration mode of g-C₃N₄ and understanding the physical mechanism of overall water splitting is important for the further improvement of the photocatalytic activity of g-C₃N₄-based materials. With core level shift and molecular dynamics simulations based on first-principles calculations, Co₁(PH)₃ anchored on the triazine of g-C₃N₄ is determined as a stable single-atom catalyst with high efficiency for photocatalytic overall water splitting. The separated spin-polarized charge density distribution of valence-band maximum and conduction-band minimum states is beneficial for the long lifetime of photoexcited electrons and holes. An anchored Co single atom site is the active site for oxygen evolution reaction, and nitrogen atoms act as active sites for hydrogen evolution reaction. This new decoration mode of g-C₃N₄ opens a possible way to functionalize g-C₃N₄ on both triazine and void sites to realize the separation of OER and hydrogenation reaction by water splitting.