Slow-light-driven photocatalytic CO2 reduction to CH4 mediated by photonic crystal Graphdiyne-Cu/ZnO Z-scheme system

Developing photocatalysts with high activity and selectivity remains a significant challenge in the field of CO 2 photoreduction for producing valuable chemical or fuel products under mild conditions. Herein, photonic crystal (PC) GDY-Cu/ZnO was constructed through the in-situ induced growth of graphdiyne (GDY) on PC Cu/ZnO surface via H 2 -reduction for efficient photoreduction of CO 2 to CH 4 . With the aid of photonic crystal structure, PC GDY-Cu/ZnO exhibits a distinctive red-edge slow light region which can significantly improve the utilization efficiency of visible light and intensify photo-catalysis. Additionally, the formed all-solid-state Z-scheme system efficiently accelerates photoelectron migration, facilitating e - /h + separation. Thirdly, the surface GDY, along with the enrich oxygen vacancies generated during H 2 reduction, enhances the adsorption and activation toward CO 2 and H 2 O on PC GDY-Cu/ZnO interface. In consequence, PC GDY-Cu/ZnO demonstrates highly photocatalytic conversion of CO 2 to CH 4 , achieving a CH 4 yield of 33.67 μmol·g −1 ·h −1 with 93.3 % selectivity via slow-light-driven photocatalysis CO 2 reduction. This work provides an efficient strategy to modify ZnO for the efficient photoreduction of CO 2 to CH 4 .