Study on graphitic carbon nitride catalysts with Bi and Cu loaded for carbon dioxide photothermal reduction

As a significant technology of CO2 utilization, artificial CO2 photoreduction has received more and more attention. Herein, g-C3N4 catalysts modified with Bi and/or Cu for CO2 photothermal reduction were prepared by solvothermal synthesis and impregnation methods. Performance evaluation and physicochemical and photo- and thermochemical characterization indicated that Bi and Cu modification effectively enhanced the photo-absorption properties of g-C3N4 catalysts, improving charge transfer efficiency and catalytic performance. Compared with single-metal modification, Bi and Cu co-modification showed a narrower bandgap and more excellent light and CO2 absorption capacity, suggesting a certain synergistic effect of Bi and Cu co-modification. The alteration of the light absorption properties may be related to the surface plasmon effect of Bi and Cu, and the co-loading of Bi and Cu can exacerbate the effect, which can effectively enhance the photoresponsivity of the catalysts, leading to higher catalytic performance.