Improved Visible-light Photocatalytic Properties of ZnFe2O4 Synthesized via Sol-gel Method Combined with a Microwave Treatment

ZnFe₂O₄(ZFO) was synthesized via a sol-gel method firstly, then the ZFO was irradiated with microwave treatment to obtain M-ZFO using NH₄Cl as dispersant for 10 min to improve the photocatalytic activity. Large particles of ZFO were broken into small and uniform particles by the gases of hydrogen chlorine and ammonia during the decomposition of NH₄Cl. Compared to ZnFe₂O₄ without microwave treatment(ZFO), M-ZFO exhibits smaller particle size, higher surface area and larger saturation magnetization. More importantly, the photocatalytic activity of M-ZFO for methylene blue was increased by 25% compared with that of ZFO.