Abstract
We report a facile fabrication of free standing, highly conducting flexible reduced graphene oxide (rGO) paper by an evaporation-induced self-assembly process. The impact of heat treatment conditions on the structural, mechanical and electrical properties of rGO paper has been investigated. The effect of annealing temperature on the structural variations of GO (graphene oxide) and rGO papers was confirmed by X-ray diffraction studies. The removal of oxygen and other functional groups from the GO paper by heat-treatment process was confirmed using FTIR analysis. Raman spectra confirmed the effective control of defects in rGO paper by means of heat-treatment, which has also been inferred from the Raman mapping analysis. The morphology of rGO paper studied by FESEM emphasized the stacking of rGO layers. The electrical conductivity was significantly enhanced for 400 degrees C heat-treated rGO paper (4.82 x 10(3) S/cm) compared to the as-prepared GO paper (7 x 10(-3) S/cm). The tensile strength of the rGO paper was also relatively higher than that of GO paper. The experimental results demonstrated that the present approach is simple and reducing agent free green approach for preparing large-area rGO paper with high electrical conductivity and mechanical flexibility.