Synthesis and Enhanced Cr(VI) Photoreduction Property of Formate Anion Containing Graphitic Carbon Nitride

In this study, we report on the synthesis of formate anion containing graphitic carbon nitride and its dramatically enhanced activity and stability on Cr(VI) photoreduction under visible light. We found that the incorporated formate anions could not only trap photogenerated holes to produce more photogenerated electrons, but also change two-step superoxide ions mediated indirect reduction to one-step direct photogenerated electron reduction of Cr(VI) over graphitic carbon nitride under visible light through inhibiting surface dioxygen adsorption and thus enhance Cr(VI) photoreduction. This study could not only develop a novel strategy to improve the Cr(VI) photoreduction activity and stability of semiconductors but also shed light on the deep understanding of the relationship between intrinsic structure and Cr(VI) photoreduction activity of semiconductor photocatalysts.