Two-dimensional tungsten oxide nanoflakes grafted over g-C3N4 as excellent electrode materials for hybrid supercapacitors

Abstract

This paper presents the successful design of nanocomposites comprising metal oxide modification over graphitic carbon nitride (g-C3N4) applicable as efficient electrode materials for hybrid supercapacitors. Two-dimensional tungsten oxide (WO3) nanoflakes were synthesized with an acid-assisted precipitation method followed by hydrothermal treatment. Nanocomposite WO3/g-C3N4 has been reported as specially designed electrode materials for supercapacitors where nano WO3 grafted over g-C3N4 nanosheets by in-situ chemical co-precipitation method. Various structural and electrochemical analyses were performed to investigate the overall morphological dependency of the charge storage phenomenon. The synthesized WO3/g-C3N4 nanocomposites exhibit superior specific capacitance of 1051.43 Fg−1 at 1 Ag−1, having a capacity retaining of 85.1 % performed at 10 Ag−1 after 10,000 cycles. However, the fabricated asymmetric supercapacitor has achieved an energy density of 114.75 Whkg−1 at 8.5 kWkg−1 power density. The combination enhancement of energy density with notable cycle stability of WO3/g-C3N4 than WO3 and g-C3N4 nanosheets are accredited to the excellent structural, thermal, and electrochemical stability possessed by the heterostructure WO3/g-C3N4 and thus proposing a promising electrode material for hybrid supercapacitors.