Hollow cubic TiO2 loaded with copper and gold nanoparticles for photocatalytic CO2 reduction

A simple photodeposition method is used to prepare Cu and Au nanoparticles modified TiO2 nanocomposites. The phase composition of the catalyst is determined by x-ray diffraction. The mutual synergistic effects of Cu and Au are analyzed using x-ray photoelectron spectroscopy, photoluminescence spectroscopy and UV diffuse reflectance spectroscopy. The results indicate that the TiO2 is anatase structure with hollow cubic morphology, which enhances the utilization of visible light and improves the photocatalytic performance compared with P25. The Cu0.7Au0.3/TiO2 has the highest carrier separation efficiency and the best photocatalytic performance with a CO yield of 6.08 umol g-1 h-1, which is about four times higher than that of TiO2 (1.56 umol g-1 h-1). The aforementioned results indicate that the photocatalytic activity for CO2 reduction is greatly enhanced by the addition of modest quantities of Cu and Au NPs. During the photocatalytic process, the presence of Au NPs absorbs visible light and modulates the surface structure of electrons, while Cu serves as an electron sink, hence promoting efficient separation of electron-hole pairs. Utilizing the distinct benefits of bimetal and their robust interactions is a viable and efficacious approach for boosting the photocatalytic activity.