Role of PVA in synthesis of nano Co3O4-decorated graphene oxide

Polymeric materials have been found to be ideal candidates for the synthesis of organic–inorganic nanomaterials. We have obtained Co3O4-decorated graphene oxide (GO) nanocomposites by a simple polymer combustion method. Polyvinyl alcohol (PVA) of two different molecular weights, 14,000 and 125,000, was used for the synthesis. The pristine sample was annealed at 300, 500, and 800°C. PVA has played an important role in the formation of GO and Co3O4 nanoparticles. Synthesized Co3O4–GO nanocomposites were characterized by X-ray diffraction, Fourier transform infrared, Raman, electron paramagnetic resonance, transmission electron microscopy, and vibrating sample magnetometry. Reflection peaks at 12° and 37° in an X-ray study confirm the formation of Co3O4–GO. Raman study validates the presence of GO in nanocomposites of Co3O4–GO. Room temperature ferromagnetism was observed in all annealed samples. The highest coercivity of 462 G was observed for 300°C annealed samples as compared with bulk Co3O4. On the basis of the results obtained, a mechanism of formation is proposed. Copyright © 2015 John Wiley & Sons, Ltd.