Facile synthesis of nitrogen-doped graphene on Ni foam for high-performance supercapacitors

Nitrogen-doped graphene deposited on nickel foam was prepared via a simple hydrothermal process using urea as the reducing agent and nitrogen source and was directly applied as a binder-free supercapacitor electrode. The N content was 5.01 at. %. The electrochemical test of the prepared N-doped graphene showed ideal and reversible capacitive behaviour and excellent electrochemical performance, with a high specific capacitance of 223 F g−1 at 0.29 A g−1, a high-rate capability with the specific capacitances maintained at 184 F g−1 at a high rate of 35.7 A g−1, and good cycling stability with the specific capacitance of the N-doped graphene increased to 206 F g−1 after 3000 cycles. The results suggest its promising application as an electrode material for supercapacitor.