Reduced graphene oxide derived from urea-assisted solution combustion route and its electrochemical performance

Reduced graphene oxide (rGO) is synthesized from graphite oxide through urea-assisted solution combustion route. X-ray diffraction analysis reveals a decrease in the interplanar spacing (d002) value from 8.14 to 3.44 Å on combustion due to reduction. Number of graphitic layers decreases from 58 to 9 on combustion indicating efficient exfoliation. Scanning electron micrographs reveal substantial reduction in the lateral dimension of graphitic planes from greater than ~1μm to less than ~380 nm. Raman spectroscopy studies indicate an enhancement of defects in the rGO with an ID/IG ratio of 1.19. Diminishing intensity of vibrational modes of different oxygen functional groups in the Fourier transform infrared spectrum and higher carbon to oxygen ratio of 12.13 from X-ray photoelectron spectroscopy indicate excellent reduction. N1s X-ray photoelectron spectrum confirms nitrogen doping. Electrical conductivity of rGO is 38 S m−1. The sample as an active material in a three-electrode configuration with 6 M KOH electrolyte exhibits a capacitance of 75.1 F g−1 at a current density of 0.1 A g−1, and 63% of it is retained even at a current density of 10 A g−1. It also exhibits 103% of its initial capacitance after 1000 cycles.