Obtaining free-standing crack-free graphene oxide and
reduced graphene
oxide films is challenging. Free-standing graphene oxide is widely
used to fabricate flexible sensors and energy storage devices. The
present work is focused on the certainty of pure precursors in preparing
crack-free graphene oxide film. Four samples of graphene oxide are
synthesized using the known Hummer’s method. The graphene oxide
films were studied using scanning electron microscopy, energy-dispersive
X-ray spectroscopy, X-ray diffraction, Raman spectroscopy, and Fourier
transform infrared spectroscopy. The fabrication of graphene oxide
free-standing film is simple and cost effective and can be produced
on a large scale for commercial applications. The obtained crack-free
graphene oxide free-standing film is 15.1 μm thick. The graphene
oxide film is thermally reduced to obtain a highly conducting, large-area,
and multilayer reduced graphene oxide film. Reduced graphene oxide
film exhibits hydrophobicity with a measured contact angle of 95°
and sheet resistance of 149.56 Ω/□. The Joule heating
experiment is performed with an external potential of 8.4 V.