Graphene–Magnetic Spinel Ferrite Nanocomposite: Facile Synthesis and Excellent Photocatalytic Performance

Abstract

Spinel ferrite structured ZnFe2O4 nanoparticles anchored on reduced graphene oxide (rGO) sheets have been prepared via a facile hydrothermal method combined with a solvothermal approach. For the synthesis of the ZnFe2O4/rGO nanocomposites, the rGO nanosheet contains epoxy functional groups serving as the active sites, which allowed the formation of uniform ZnFe2O4 nanoparticles. Due to the structure of the ZnFe2O4/RGO nanocomposites, the aggregation of the ZnFe2O4 nanoparticles can be readily disrupted and electronic transfer through the rGO nanosheets is accelerated. This could in turn enhance the photocatalytic efficiency. It was also demonstrated that ZnFe2O4/rGO (40 wt-%) hybrid nanocomposites almost reached adsorption equilibrium in the RhB dye within 60min. The Langmuir equation model showed that the photodegradation of RhB was well fitted to first order reaction kinetics with k=0.6254min−1. This illustrated that the addition of GO could reduce the bandgap of pure ZnFe2O4, which avoided the combination of electrons and holes. The ZnFe2O4/rGO nanocomposites could also enhance the utilisation of sunlight. In addition, the ZnFe2O4/rGO nanocomposite photocatalyst also demonstrated a supramagnetic property, holding potential to be utilised for water treatment.