Nanocellulose-assisted low-temperature synthesis and supercapacitor performance of reduced graphene oxide aerogels

Here, we have synthesized reduced graphene oxide (rGO) aerogels using a nanocellulose-assisted low temperature (less than 500 degrees C) thermal treatment route where nanocelluloses promote the gelation of graphene oxide (GO) solution that benefits the fabrication of GO aerogels from low concentration dispersion (2.85 mg mL(-1)), and after their thermal decomposition the residual nanofibers act as spacer both prevent the re-stacking of graphene sheets and integrate with rGO sheets to give a particular kind of carbon-based aerogel along with numerous defects (holes). Thermal decomposition of nanocellulose appears to be complete beyond 350 degrees C thus its presence in form of amorphous carbon nanofibers in rGO sheets. The rGO aerogels synthesized at 350 degrees C provide the best balance in terms of wide interlayer spacing, high content of CO-type functional groups, and high defects content. This translates into a high discharge capacitance of 270 F g(-1) at a current rate of 1 A g(-1) for compressed rGO aerogels without any binder or conductive additive. Detailed electrochemical tests using 6 M KOH electrolyte establish the fact that pseudocapacitance component has substantial contribution towards the overall capacitance; closely approaching the contribution of the double layer capacitance that is the most dominant capacitance component. (C) 2017 Elsevier B.V. All rights reserved.