Planar on-chip interdigital microelectrodes based on nitrogen and oxygen co-doped graphene quantum dots for microsupercapacitors

Abstract

The electrochemical performances of microsupercapacitors depend on the electrode materials. And graphene quantum dots are a very ideal electrode materials. In particular, nitrogen or oxygen doping is beneficial to enhance the Faraday reaction kinetics and improve the interfacial wettability of the carbon electrode and electrolyte solution. In this paper, nitrogen and oxygen co-doped graphene quantum dots were used as electrode materials and the electrode film was prepared by a modified liquid-air interface self-assembly method. The microsupercapacitors had high electrochemical characteristics including the area capacitance which was 98 μF cm−2, the energy density which was 0.014 μWh cm−2, the power density which was 51.07 μW cm−2 and the excellent time constant which was 0.12 ms. Meanwhile, the capacitance retention rate was 97.3% after 10,000 cycles.