Synthesis of heterostructure SnO2/graphitic carbon nitride composite for high-performance electrochemical supercapacitor

Abstract The SnO2/g-C3N4 heterostructure composite is prepared by a simple hydrothermal reaction. The composite can be a supercapacitor electrode material and exhibits good specific capacitance of 488 F g−1 at the current density of 1 A g−1 within a potential window of 0–1 V in 1 M H2SO4 solution. After 5000 cycles, the heterostructure SnO2/g-C3N4 composite shows 97.2% and 73.4% of the capacitance retention rate at the current densities of 10 A g−1 and 20 A g−1, respectively. A symmetric supercapacitor device is successfully fabricated based on the SnO2/g-C3N4 composite, which shows a specific capacitance of 153 F g−1. Moreover, the device can deliver the energy density of 2.8 Wh kg−1 at the power density of 5684 W kg−1.