Bibonding Constructing Coordinatively Unsaturated Znⁱ⁺(0 < i < 2) Sites for Enhanced Photo‐Fenton Activity

Abstract The coordinatively unsaturated metal sites (CUMSs) have attracted widespread attention for enhancing catalytic activity. This study reports a controllable “bibonding” method to construct the coordinatively unsaturated Znⁱ⁺ (0 < i < 2) active sites by forming N_(g‐C3N4)‐Zn—N_(imidazole) under mild experimental conditions. The catalysts with Znⁱ⁺ are used for the photo‐Fenton reaction to degrade methylene blue (MB) without any oxidant. The degradation efficiency is positively correlated with Znⁱ⁺. The Znⁱ⁺ improved the Fe²⁺/Fe³⁺ conversion efficiency and the H₂O₂ generation ability of the catalyst. The optimized catalysts with 2.27% of Znⁱ⁺ present a photo‐Fenton degradation efficiency of MB as 73.45 mg g⁻¹ at pH 7 and 78.54 mg g⁻¹ at pH 4. This strategy can be used to construct CUMSs for a series of narrow bandgap semiconductor materials containing nitrogen atoms.