Preparation of CeO₂-Quantum Dots/Cu₂O Nanocomposites with Enhanced Photocatalytic Properties.

To improve the efficiency of photocatalysts, a composite of CeO2-quantum dots/Cu2O (CeO2-QDs/Cu2O) was prepared through a one-step hydrothermal procedure in alkaline carbonate solution with Cu2(OH)2CO3 and Ce(NO3)3. 6H2O as precursors and glucose as reducing agent. The morphologies and structures of the prepared photocatalysts were well characterized utilizing Transmission Electron Microscopy (TEM), X-ray Diffractometry (XRD), X-ray Photoelectron Spectroscopy (XPS) and UV-Vis Diffuse Reflectance Spectrophotometer (DRS). The results indicated that the CeO2-QDs with 5 to 10 nm diameters were well dispersed and had a good contact with Cu2O. As observed in the photocatalytic experiments, Rhodamine B could be degraded more effectively under simulated sunlight using CeO2-QDs/Cu2O as the photocatalysts. Also, the obtained photocatalytic kinetics constant was higher than that in the experiments using CeO2 or Cu2O nano particles as photocatalysts. The enhanced photocatalytic activities might be attributed to the efficient separation of photo-generated charge carriers with the help of the p-n heterojunction and the morphology of quantum dots.