Growth and properties of ZnO/ZnFe₂O₄ nanoparticles

ZnO/ZnFe2O4 nanoparticles were synthesized by hydrothermal and annealed method. X-ray diffraction(XRD), scanning electron microscopy(SEM) and photoluminescence(PL) spectroscopy were used to characterize the synthesized and annealed ZnO/ZnFe2O4 nanoparticles. The results indicate that the synthesized nanoparticles are mainly composed of hexagon wurtzite ZnO and cubic ZnFe2O4, and the crystal quality is improved by annealing treatment. It is observed that the intrinsic photoluminescence attributed to the recombination of photogenerated carriers of ZnO was obviously weakened after annealing process, which confirms that a ZnO/ZnFe2O4 heterojunction was formed which could improve the separation of photogenerated carriers. Photocatalytic test's results show the photocatalytic activity of the annealed ZnO/ZnFe2O4 nanoparticles is better than the synthesized, and the photocatalytic degradation ratio of MO is 50.48% under 3 hours' UV-illumination. The magnetic properties of the annealed ZnO/ZnFe2O4 were also investigated, the synthesized nanoparticles were paramagnetic at room temperature, and the annealed nanoparticles were ferromagnetic. In conclusion, the annealed ZnO/ZnFe2O4 nanoparticles may have a great potential in the magnetic photocatalytic fields.