High-performance supercapacitors based on the reduced graphene oxide hydrogels modified by trace amounts of benzenediols

- Reduced graphene hydrogels were prepared in presence of tiny amount of benzenediols.
- The prepared rGOHGs with various benzenediols have different 3D porous structures.
- Capacitive property of rGOHGs has been obviously improved by modifying benzenediols.
- Cells assembled by them show high capacitance, rate capability and cyclic stability.

Reduced graphene oxide hydrogels (rGOHGs) with three-dimensional (3D) porous structure are considered as promising electrode materials for supercapacitors. Here, the 3D rGOHGs have been prepared in presence of trace amount of benzenediols and their capacitive performances have been significantly improved. The optimized samples prepared by controlling mass ratios of graphene oxide (GO) to benzenediols to be about 80, 40 and 40 for o-, p-, and m-benzenediols have specific capacitance of about 253, 240 and 238 F g−1 at 1 mV s−1, respectively. Furthermore, rGOHGs prepared in presence of different benzenediols exhibit different microstructures, and that modified with o-benzenediol possesses the largest specific surface area and total pore volume. Particularly, the rGOHGs modified with o-, p-, and m-benzenediols have fairly good rate-capability, and retain 98.1%, 96.9% and 95.5% of their initial capacitance respectively after 10,000 charging/discharging cycles, revealing their excellent stability. This provides a strategy to improve the capacitive properties of rGOHGs significantly by tiny amount of modifiers.

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