g-C3N4 foam/Cu2O QDs with excellent CO2 adsorption and synergistic catalytic effect for photocatalytic CO2 reduction

A unique heterostructure is developed based on a 3D photoactive semiconductor and a 0D Cu2O QDs for superb photocatalytic reduction CO2 into CO. It reported a novel and simple method to prepare a 3D g-C3N4 foam with micron-sized porous structures using ultrastable foam as a soft template for the first time. Moreover, Cu2O QDs are loaded onto 3D g-C3N4 foam through a simple photodeposition strategy. Systematically characterization demonstrated that g-C3N4 foam not only act as an excellent carrier for Cu2O QDs, but also greatly improve the photocatalytic performance by enhancing CO2 adsorption and gas transfer. Simultaneously, the rationally designed g-C3N4 foam/Cu2O QDs exhibited notablely enhancement in photocatalytic performance with 3.9 times and 11 times higher than that of g-C3N4 foam and bulk g-C3N4 powder. The excellent photocatalytic activity can be attributed to the unique porous structure and the synergistic effect between g-C3N4 foam and Cu2O QDs, which can speed up the transfer of charge carriers and urged the cumulation of photo-generated electrons on the Cu2O QDs. Our work provides new ideas for constructing 0D/3D hierarchical photocatalytic systems, which may provide guidance on designing efficient photocatalysts to maximize photocatalyst kinetics.