Anchoring Active Pt 2+ /Pt 0 Hybrid Nanodots on g‐C 3 N 4 Nitrogen Vacancies for Photocatalytic H 2 Evolution

A Pt 2+ /Pt 0 hybrid nanodot‐modified graphitic carbon nitride (CN) photocatalyst (CNV‐P) was fabricated for the first time using a chemical reduction method, during which nitrogen vacancies in g‐C 3 N 4 assist to stabilize Pt 2+ species. It is elucidated that the coexistence of metallic Pt 0 and Pt 2+ species in the Pt nanodots loaded on g‐C 3 N 4 results in superior photocatalytic H 2 evolution performance with very low Pt loadings. The turnover frequencies (TOFs) are 265.91 and 116.38 h −1 for CNV‐P‐0.1 (0.1 wt % Pt) and CNV‐P‐0.5 (0.5 wt % Pt), respectively, which are much higher than for other g‐C 3 N 4 ‐based photocatalysts with Pt co‐catalyst reported previously. The excellent photocatalytic H 2 evolution performance is a result of i) metallic Pt 0 facilitating the electron transport and separation and Pt 2+ species preventing the undesirable H 2 backward reaction, ii) the strong interfacial contact between Pt 2+ /Pt 0 hybrid nanodots and nitrogen vacancies of CNV facilitating the interfacial electron transfer, and iii) the highly dispersed Pt 2+ /Pt 0 hybrid nanodots exposing more active sites for photocatalytic H 2 evolution. Our findings are useful for the design of highly active semiconductor‐based photocatalysts with extremely low precious metal content to reduce the catalyst cost while achieving good activity.