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

Abstract

A visible light-driven magnetic Ag/β-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/β-Ag₂WO₄/CoFe₂O₄ nanocomposite exhibit a flower-like morphology and average diameter of 35 and 43 nm, respectively. The Ag/β-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/β-Ag₂WO₄. The photocatalytic efficiency of the CoFe₂O₄ and Ag/β-Ag₂WO₄ nanoparticles is 43% and 51%, respectively, whereas for Ag/β-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/β-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.