Achieving efficient photoreduction of CO2 by simultaneously facilitating the splitting of H2O and the conversion of *CO intermediates

Photocatalytic reduction of CO2 with H2O to hydrocarbon fuels is considered a promising approach to address environmental and energy challenges. However, the efficiency of CO2 photoreduction remains unsatisfactory due to limitations in the reaction rates of CO2 and H2O. This study focuses on the development of defect and organic molecule (3,5-Diamino-1,2,4-triazole, DATZ) modified carbon nitride catalysts (g-CN-DZT) for enhancing the photoreduction of CO2 with H2O. The introduction of defect structures could disrupt the hydrogen bonds and alters the adsorption behavior of OH groups, leading to improved H2O splitting kinetics. Additionally, the incorporation of the organic molecule DATZ facilitates the conversion of *CO intermediates to CO, enhancing the overall CO2 conversion rate. The modified catalyst g-CN-DZ625 exhibits enhanced CO2 capture ability. Meanwhile, N defect serves as an active site for CH4 production. Experimental results show that g-CN-DZ625 demonstrates CO and CH4 evolution rate of 11.86 and 4.45 mu molg-1h-1, respectively, that is 3.62 and 18.54 times higher than that of g-CN-625. The reaction mechanism was further elucidated through in-situ FTIR and DFT simulations.