Microwave-assisted synthesis of α-Fe2O3/ZnFe2O4/ZnO ternary hybrid nanostructures for photocatalytic applications

Abstract

Solar-driven highly efficient photocatalytic decomposition of toxic organic contaminants using magnetically separable α-Fe2O3/ZnFe2O4/ZnO ternary hybrid nanodiscs is reported. α-Fe2O3/ZnFe2O4/ZnO ternary hybrid nanostructures were synthesized by microwave-assisted co-precipitation and simple co-precipitation methods and well characterized by XRD, micro-Raman, FESEM and UV–vis spectroscopy. FESEM micrographs revealed nanodiscs in case of microwave-assisted co-precipitation whereas nanoparticles and their aggregates were formed under co-precipitation combined with calcination. XRD and Raman studies confirmed the hybrid nature of prepared α-Fe2O3/ZnFe2O4/ZnO nanostructures. Photocatalytic performance of α-Fe2O3/ZnFe2O4/ZnO hybrid nanostructures was investigated by carrying out the photodegradation of organic dyes MB and MG under solar light illumination. The prepared α-Fe2O3/ZnFe2O4/ZnO ternary hybrid magnetic nanodiscs decomposed MB and MG dyes in only 32 and 24 min, respectively. α-Fe2O3/ZnFe2O4/ZnO hybrid nanodiscs showed excellent photocatalytic performance together with reusability and easy magnetic separation demonstrating its suitability for solar-driven photocatalytic water purification applications. In-situ scavenger studies showed •OH radicals are the main active radicals in solar-driven photocatalysis by α-Fe2O3/ZnFe2O4/ZnO nanodiscs. The tentative mechanism of growth of α-Fe2O3/ZnFe2O4/ZnO ternary hybrid nanodiscs and the photocatalytic mechanism are discussed.