Hydrangea‐like ZnO nanospheres on Al substrates via hydrothermal synthesis for photocatalytic activity

Hydrangea‐like ZnO nanospheres were fabricated on Al substrates via a facile hydrothermal method with only one step. Scanning electron microscopy, energy‐dispersive spectroscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, and photoluminescence were used to investigate their morphology, component, structure, and optical properties. The hierarchical nanospheres are fabricated by 2D nanosheets with the shape of 3D sphere. By adjusting the reaction time, the formation process was monitored. The photocatalytic activity of ZnO nanospheres was also investigated for their dye degradation, and they exhibit good photocatalytic ability to congo red, with the degradation rate of 98.4%. Besides, they have universal catalysis effect on methyl orange. Hierarchical ZnO nanospheres were synthesized on Al substrates with only one step via hydrothermal method. Fabricated by 2D nanosheets with the shape of 3D sphere, they have a high contact area with pollutant solution and exhibit good photocatalytic ability to congo red and methyl orange. The absorption around the visible light range leads to enhanced photocatalytic ability, caused by numerous defect energy levels.