Photocatalytic application of hollow CuO microspheres with hierarchical dandelion-like structures synthesized by a simple template free approach

• For the first time, we synthesized hollow dandelion-like CuO via a simple method.
• The method was low temperature, template free and low cost wet chemical reaction.
• The prepared CuO was applied for photodegradation of methylene blue.
• The photocatalytic reaction was carried out under UV and visible light irradiation.

In this study, hollow copper oxide microspheres were synthesized by a simple and low cost co-precipitation reaction of Cu(NO3)2·3H2O and ammonia without catalyst, template or surfactant. The prepared CuO was characterized by XRD, FT-IR spectroscopy, DRS and SEM images. The morphology of the CuO powder consists of Hierarchical dandelion-like structures contain one-dimensional nanoribbons with the average size of 20–30 nm according to SEM images. The XRD pattern showed that the synthesized CuO nanostructures have a high crystallinity with monoclinic crystal structure. The prepared CuO was applied for photodegradation of methylene blue under UV and visible light irradiation and showed good photocatalytic performance to degrade the dye (for 5 mg L−1 MB solution: 97.3% degradation).