One-step hydrothermal synthesis of CuO hollow spheres with high photocatalytic activity

Hollow copper oxide spheres with a diameter of 1.5–2 μm were prepared by hydrothermal reaction at 170 °C for 10 h in one step. The product was characterized by SEM, XRD, XPS, and EDX. We deduced the possible formation mechanism of the morphology through its nucleation process. Ostwald ripening process and NH3 produced by urea should be the main reason for the formation of hollow structure. We also explore the effects of different experimental conditions and find that the morphology is controllable. Finally, the photocatalytic experiments showed that the products have excellent photocatalytic activity and can be used in wastewater treatment.