Abstract
Background: Various studies have been carried out on MnOx supported on high-surface area nano-carbon based supports like CNTs and graphene. Most methods reported in literature use lengthy procedures involving multiple steps to grow MnOx nanostructures on reduced graphene oxide. Moreover, most methods using ultrasonication or electrochemical deposition of MnOx use KMnO4 as the precursor, which invariably leads to K impurities.
Objective: Manganese oxide and partially reduced graphene oxide (MnOx-PRGO) nano-hybrids were prepared using a one step wet chemical process to study their magnetic properties. Method and Results: A simple wet chemical method via a combination of microwave and sonication processes was utilized to prepare MnOx-PRGO nano-hybrids with different MnOx loadings. The combination of the two processes allowed control over minimising the residual K impurities in such systems. The as-prepared MnOx-PRGO nano-hybrids were extensively characterised using transmission electron microscopy, Fourier transform-Infra-red spectroscopy, thermo-gravimetric analysis and X-ray photoelectron spectroscopy. Conclusion: The MnOx-PRGO nano-hybrids responded to magnetic fields at room temperature, which was dependant on the MnOx loading. The system showed some ferromagnetic behaviour at low applied magnetic fields with Hc = 127.5 Oe and remanant magnetisation of 0.076 emu/g. The Neel temperature was found to be 9 K. The hybrid system showed paramagnetic behaviour with a near linear 1/χversus T plot.Keywords: Graphene, magnetic properties, manganese oxide, microwave, residual oxygen functional groups, ultra sonication.
Graphical Abstract