Unique PCoN Surface Bonding States Constructed on g-C₃N₄ Nanosheets for Drastically Enhanced Photocatalytic Activity of H₂ Evolution

Developing high-efficiency and low-cost photocatalysts by avoiding expensive noble metals, yet remarkably improving H₂ evolution performance, is a great challenge. Noble-metal-free catalysts containing Co(Fe)NC moieties have been widely reported in recent years for electrochemical oxygen reduction reaction and have also gained noticeable interest for organic transformation. However, to date, no prior studies are available in the literature about the activity of N-coordinated metal centers for photocatalytic H₂ evolution. Herein, a new photocatalyst containing g-C₃N₄ decorated with CoP nanodots constructed from low-cost precursors is reported. It is for the first time revealed that the unique P(δ⁻)Co(δ⁺)N(δ⁻) surface bonding states lead to much superior H₂ evolution activity (96.2 µmol h⁻¹) compared to noble metal (Pt)-decorated g-C₃N₄ photocatalyst (32.3 µmol h⁻¹). The quantum efficiency of 12.4% at 420 nm is also much higher than the record values (≈2%) of other transition metal cocatalysts-loaded g-C₃N₄. It is believed that this work marks an important step toward developing high-performance and low-cost photocatalytic materials for H₂ evolution.