Enhanced photocatalytic performance of ferromagnetic ZnO:Cu hierarchical microstructures

Ferromagnetic ZnO:Cu microstructures were synthesized by a hydrothermal method. With the Cu doping concentration increasing, the morphology of the ZnO:Cu microstructures changed from rods to hierarchically stacked disks. The photoluminescence of the ferromagnetic ZnO:Cu samples showed an UV emission band and a green emission. When the Cu doping concentration increased to 5%, the center wavelength of the UV emission band shifted from 389 nm to 399 nm due to the band narrowing effect, and the green emission was enhanced due to the increase of the defect states on the surface of the hierarchical structure with high surface-to-volume ratio. Utilizing the large surface-to-volume ratio of the hierarchical ZnO:Cu microstructure, photocatalytic activity for the degradation of Rhodamine B was measured, the result showed that the ferromagnetic hierarchical ZnO:Cu was more efficient than the undoped ZnO.