In situ construction of 1D/2D ZnO/graphdiyne oxide heterostructures for enhanced photocatalytic reduction in a gas phase

Abstract

In this study, a 1D/2D ZnO nanofiber/graphdiyne oxide heterojunction was designed for photocatalytic CO₂ reduction, and the difference between graphdiyne and graphdiyne oxide was investigated as co-catalysts. The ZGDO heterostructure has strong reactant adsorption capacity due to the enlarged specific surface area and abundant hydrophilic oxygen-containing functional groups. DFT calculations, EPR, and in situ XPS further verified the S-scheme charge transfer mechanism in ZGDO. In contrast, the abilities of GD to adsorb CO₂ and enhance light absorption are not as good as those of GDO, and the band structure of GD is not conducive to the formation of a favorable electric field drive at the interface with ZnO. The CO yield of ZGDO with only 3% GDO was up to 34.9 μmol h⁻¹ g⁻¹ in the gas–phase photocatalytic reduction of CO₂, which was 4.4, 24, and 1.5 times that of ZnO, GDO, and ZnO/GD, respectively. This work opens new possibilities for the application of new non-metallic photocatalysts in the photoreduction of CO₂.