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. [ABSTRACT FROM AUTHOR]