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 NH4C1 as dispersant for 10 min to improve the photocatalytic activity. Large par- tides 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.