Preparation and Characterization of CuO—TiO2 Composite Hollow Nanospheres with Enhanced Photocatalytic Activity Under Visible Light Irradiation

: CuO-TiO₂ composite hollow nanospheres were synthesized using polystyrene as a template. Transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were used to characterize the average diameter, shell thickness, crystalline structure, and composition of CuO-TiO₂ composite hollow nanospheres. UV-vis absorption spectrum was used to measure the optical absorption property of the CuO-TiO₂ composite hollow nanospheres. The photocatalytic performance of the samples was characterized by degrading 10 mg·L-1 methylene blue under visible light irradiation. The results showed that the CuO-TiO₂ composite hollow nanospheres exhibited better photocatalytic performance than the pure TiO₂ nanoparticles and TiO₂ hollow nanospheres. The improvement in photocatalytic performance was attributed to the enhanced light absorption in the visible light region.