Regulating Local Electron Density of Cyano Sites in Graphitic Nitride Carbon by Giant Internal Electric Field for Efficient CO Photoreduction to Hydrocarbons.

Selective photocatalytic CO reduction to high-value hydrocarbons using graphitic carbon nitride (g-CN) polymer holds great practical significance. Herein, the cyano-functionalized g-CN (CN-g-CN) with a high local electron density site is successfully constructed for selective CO photoreduction to CH and CH. Wherein the potent electron-withdrawing cyano group induces a giant internal electric field in CN-g-CN, significantly boosting the directional migration of photogenerated electrons and concentrating them nearby. Thereby, a high local electron density site around its cyano group is created. Moreover, this structure can also effectively promote the adsorption and activation of CO while firmly anchoring *CO intermediates, facilitating their subsequent hydrogenation and coupling reactions. Consequently, using HO as a reducing agent, CN-g-CN achieves efficient and selective photocatalytic CO reduction to CH and CH activity, with maximum rates of 6.64 and 1.35 µmol g h, respectively, 69.3 and 53.8 times higher than bulk g-CN and g-CN nanosheets. In short, this work illustrates the importance of constructing a reduction site with high local electron density for efficient and selective CO photoreduction to hydrocarbons.