Novel nanomagnetic Ag/beta-Ag2WO4/CoFe2O4 as a highly efficient photocatalyst under visible light irradiation

A visible light-driven magnetic Ag/-Ag2WO4/CoFe2O4 nanophotocatalyst is successfully prepared using a facial method and characterized via FT-IR, XRD, SEM, EDS, VSM, DRS, BET, TEM, XPS and PL analysis. The obtained CoFe2O4 nanoparticles and Ag/-Ag2WO4/CoFe2O4 nanocomposite exhibit a flower-like morphology and average diameter of 35 and 43 nm, respectively. The Ag/-Ag2WO4/CoFe2O4 nanocomposite exhibits a two-fold enhancement in photocatalytic activity toward the oxidation of primary alcohols under visible light irradiation compared to that of CoFe2O4 and Ag/-Ag2WO4. The photocatalytic efficiency of the CoFe2O4 and Ag/-Ag2WO4 nanoparticles is 43% and 51%, respectively, whereas for Ag/-Ag2WO4/CoFe2O4 it is 85%. This enhancement in photocatalytic activity is attributed to the effective separation of electron-hole pairs. The trapping experiment shows that OH and h(+) are the main species involved in the photocatalytic activity of the Ag/-Ag2WO4/CoFe2O4 nanocomposite system. This robust and high-performance magnetic photocatalyst is recovered easily with a permanent magnet and can be reused five times without significant changes in its efficiency. Also, a radical chain mechanism is proposed.