Magnetically separable core–shell ZnFe2O4@ZnO nanoparticles for visible light photodegradation of methyl orange

Abstract

Visible light photodegradation of aqueous methyl orange using magnetically separable core–shell ZnFe2O4@ZnO nanoparticles is reported. A combination of low temperature (190°C) microwave synthesis and hydrothermal method were used to prepare phase pure material with excellent yield (95%). The magnetic separability, surface area of 41m2/g and visible light absorption make ZnFe2O4@ZnO nanoparticles a good solar photocatalyst. ZnFe2O4@ZnO displayed greater UV photocatalytic efficiency than ZnO owing to the generation of large number of electron-hole pairs. Visible light photodegradation of MO using ZnFe2O4@ZnO nanoparticles is reported for the first time. Higher first order rate constants under both UV and visible light for core-shell nanoparticles suggested their superiority over its individual oxides. The ZnFe2O4@ZnO showed excellent reusability with high photocatalytic efficiencies suggesting its suitability for solar photocatalytic applications.