Montmorillonite as the multifunctional reagent for preparing reduced graphene oxide and its improved supercapacitive performance

Reduced graphene oxide (rGO) was prepared using oxalic acid in the presence of montmorillonite (Mt) via hydrothermal treatment. The structure characterizations indicated that the porous structure of the obtained rGO and the residual oxygen groups were dominated by carbonyl and carboxyl groups. The mechanism analysis showed that the introduction of Mt. ensured the formation of isolated graphene oxide nanosheets free from being reduced by oxalic acid, further alleviating the irreversible restacking of rGO sheets. Electrochemical measurements demonstrated that the resultant rGO electrode offered a high specific capacitance (C-s) of 315 F/g at 1 A/g in a three-electrode configuration and the symmetric supercapacitor based on this electrode exhibited superior cycle stability with 89.7% capacitance retention after 10,000 cycles. This present work proposes a novel strategy for controlling the effects of oxalic acid on GO via employing multi-role Mt., also expands the preparation scope of graphene-based electrode materials.