Reduced graphene oxide-loaded-magnetite: A Fenton-like heterogeneous catalyst for photocatalytic degradation of 2-methylisoborneol

Abstract

A reduced-graphene-oxide-loaded magnetite (rGOF) composite was successfully synthesized by co-precipitation method for photocatalytic degradation of an odorous water contaminant 2-methylisoborneol (MIB). This heterogeneous Fenton-like catalyst degraded the recalcitrant MIB under both UV and solar light irradiations at neutral pH without the addition of other chemicals. Bare magnetite (Fe3O4) degraded only 22.5% of MIB because of rapid charge recombination. In comparison, the degradation efficiency increased to 99% for 10% (by weight) reduced graphene oxide (rGO) loading in magnetite. The addition of the rGO not only increased the adsorption capacity by increasing surface area but also increased the photodegradation efficiency synergistically by separating the electron–hole pairs, indicated by the photoluminescence spectra. The reduction in aggregation of Fe3O4 nanoparticles was explained by the increase in d-spacing and with FE-SEM images. The impedance and photocurrent data also proved the transfer of electron in presence of light in the hybrid composite. The rGOF composite presented excellent ferromagnetism, which made its recovery very easy. The recycled composite showed significantly high photocatalytic activity even after the fifth cycle with increased adsorption capacity of the recycled composite. Degradation mechanism and degradation pathway have been proposed and intermediates were identified.