Pyrolysis-assisted synthesis of two-dimensional graphitic carbon nitride nanosheets embedded with transition metal oxide (Ni or Fe) for high-performance asymmetric supercapacitors
R.S. Santos, R. Suresh Babu, T. S. Lessa, Leandro Marques Samyn, Rajangam Vinodh, R. Vivekananth, A. L. F. de Barros
Abstract
This study employed a one-step pyrolysis-assisted technique to successfully synthesized with two different transition metal oxides (M = Ni, Fe) embedded on graphitic carbon nitride nanosheets (g-C 3 N 4 -NS). The resulting nanocomposites exhibit exceptional electrochemical performance in supercapacitor applications due to various parameters such as morphology, specific surface area and crystallinity. Notably, the NiO/g-C 3 N 4 -NS and Fe 2 O 3 /g-C 3 N 4 -NS electrodes simplify the Faradaic reactions and achieve the maximum capacitance of 816 F g −1 and 703 F g −1 at 0.5 A g −1 , respectively. Additionally, these electrodes demonstrate superior cycling stability, retaining approximately 96 % of their capacity retention after 5000 cycles. Furthermore, the NiO/g-C 3 N 4 -NS//AC and Fe 2 O 3 /g-C 3 N 4 -NS//AC devices exhibit promising supercapacitor device performance, yielding respectable specific capacity of 53 F g −1 (NiO/g-C 3 N 4 -NS//AC) and 43.5 F g −1 (Fe 2 O 3 /g-C 3 N 4 -NS//AC) at 0.5 A g −1 , underscoring the commendable rate capability of the asymmetric electrodes and the energy densities of 19 Wh kg −1 and 16 Wh kg −1 at a power density of 400 W kg −1 , respectively. These findings underscore the potential of metal oxide/g-C 3 N 4 -NS composites as an electrode material for power storing applications, as demonstrated by these asymmetric supercapacitor devices.