The effect of substrate temperatures on the structural and conversion of thin films of reduced graphene oxide

Thin films of reduced graphene oxide were deposited by spray pyrolysis technique at different substrate temperatures (Ts = 50, 100, 150, 200, 250 and 300 °C). All samples synthesised by this method were characterised by different techniques, such as FTIR, Raman spectroscopy, field emission scanning electron microscope, X-ray diffraction analysis, energy-dispersive X-ray spectroscopy and UV–Vis spectroscopy. The results showed that the conversion starts from 150 °C and appears to a great extent at 300 °C. The electron micrograph image shows low roughness and homogeneity at 300 °C. The EDX results showed a decreased percentage in oxygen content and an increase in carbon content, which reflects the reduction of graphene oxide. The Fourier-transform infrared spectroscopy, Raman and UV–Vis analysis also revealed the formation of reduced graphene oxide. The conductance or resistance study shows that as the temperature increases the resistance if the thin films decreases i.e. conductivity increases.