Constructing the asymmetrically coordinated Pt single atoms by doping g-C₃N₄ support for enhanced photocatalytic...

Photocatalytic plastic reforming for H₂ production offers a promising eco-friendly strategy for waste resource upcycling, yet constructing efficient single-atom photocatalysts remains a challenge. Herein, we report a support doping strategy to tailor the coordination environment of single atoms, and develop a single-atom Pt decorated P-doped g-C₃N₄ photocatalyst (Pt₁/PCN). The Pt₁/PCN featuring an asymmetric PtN₃ structure exhibits a H₂ production rate of 2722.8 μmol g^-1 h^-1, which is 17.3 times that of Pt/CN and 7.8 times that of Pt₁/CN, and outperforms previously reported CN-based photocatalysts. Mechanistic studies indicate that the asymmetric PtN₃ configuration enhances the internal electric field, effectively facilitating the separation of photogenerated charges. Meanwhile, the doped P atoms serve as electron donors to alleviate the electron deficiency of Pt sites, promoting the upward shift of the d-band center of Pt, thereby optimizing the reaction kinetics for H₂ evolution. More importantly, the practical applicability of Pt₁/PCN is demonstrated by its excellent performance in outdoor photocatalytic plastic reforming for H₂ production. This work presents a rational design strategy for the construction of efficient single-atom photocatalysts and provides in-depth insights into the atomic-level mechanism of H₂ evolution.