A strategy for enhancing the photoactivity of g-CN-based single-atom catalysts via sulphur doping: a theoretical study.

Single-atom catalysts (SACs) have received intense attention owing to their maximum utilization efficiency of metal atoms and high catalytic activity. Although SACs possess many merits, such as high activity, selectivity and stability in photocatalysis, the difficulty of fabricating atomically dispersed atom catalysts with a high level of metal loading limits their practical applications. Here, a sulphur-doping strategy was proposed to enhance the incorporation of single Pt atoms in monolayer graphitic carbon nitride (g-CN), and the structural, electronic and optical properties were investigated through density functional theory (DFT) calculations. This work verified that SACs based on sulphur-doped monolayer g-CN (S-g-CN) exhibit a lower band gap energy, higher photocatalytic oxidation ability, easier charge separation, lower oxidation state of Pt atoms and wider light absorption range. This work provides a promising path for fabricating efficient g-CN-based photocatalytic SACs.