Visible-light-driven nano photocatalysts of Ag/β-Ag2WO4 and Ag2MoO4 based on CoFe2O4 magnetic nanoparticles were prepared by the decoration of Ag/β-Ag2WO4 and Ag2MoO4 nanoparticles on the surface of CoFe2O4 nanoparticles by a facile in situ coprecipitation method at room temperature [1,2]. The mean crystallite size of Ag/β-Ag2WO4/CoFe2O4 and Ag2WO4/CoFe2O4 was around 43 and 39 nm with flower and grain-like morphology, respectively. The photocatalytic activity of Ag/β-Ag2WO4/CoFe2O4 nanocomposite for the oxidation of benzyl alcohol was enhanced by 85%, while the CoFe2O4/Ag2MoO4 reached 82% under visible light irradiation. This photocatalyst consisting of Ag/β-Ag2WO4, Ag2MoO4, and CoFe2O4 nanostructures combines the high photocatalytic activity of Ag/β-Ag2WO4 and Ag2MoO4 and the stability and magnetism of CoFe2O4. This photoactivity enhancement was attributed to the impressive separation of electron-hole pairs [3]. The trapping experiments confirm the role of both positive holes (h+) and hydroxyl radical (˚OH) groups in the proposed mechanism [4]. These robust and high-performance magnetic photocatalysts were recovered easily by a magnet and reused several times without considerable changes in performance [1].
