Core-shelled Zn/ZnO microspheres synthesised by ultrasonic irradiation for photocatalytic applications

Core-shelled Zn/ZnO microspheres were prepared by ultrasonic irradiation to investigate their photocatalytic activity for degrading methyl orange in waste water. The microstructural and optical properties of the core-shelled Zn/ZnO microspheres were investigated by means of a scanning electron microscope, a transmission electron microscope, an X-ray diffractometer and a photoluminescence spectrometer. The results indicated that the metallic Zn core was about 6 μm in diameter whereas the ZnO shell was about 200 nm in thickness. Owing to the metal-semiconductor junction formed at the Zn/ZnO interface, the core-shelled Zn/ZnO microspheres exhibited higher photocatalytic activity for degrading methyl orange in water when compared with that of ZnO nanoparticles. It suggests that the core-shelled Zn/ZnO microspheres are a promising photocatalyst for the degradation of organic pollutants in water.