Preparation and photocatalytic activities of 3D flower-like CuO nanostructures

Hierarchical 3D flower-like CuO nanostructures on the Cu substrates were synthesized by a wet chemical method and subsequent heat treatment. The synthesis, structure and morphologies of obtained samples under different concentrations of Na₂S₂O₃ were investigated in detail and the possible growth mechanisms of the 3D flower-like CuO nanostructures were discussed. Na₂S₂O₃ plays a key role in the generation of the 3D flower-like CuO nanostructures. When the concentration of Na₂S₂O₃ is more than 0.4 mol/L, the 3D flower-like CuO nanostructures can be prepared on the Cu foils. The photocatalytic performances were studied by analyzing the degradation of methyl orange (MO) in aqueous solution in the presence of hydroxide water (H₂O₂). The 3D flower-like CuO nanostructures exhibit higher photocatalytic activity (96.2% degradation rate) than commercial CuO particles (36.3% degradation rate). The origin of the higher photocatalytic activity of the 3D flower-like CuO nanostructures was also discussed.