Polyindole modified g-C3N4 nanohybrids via in-situ chemical polymerization for its improved electrochemical performance.

In this work, surface modification of graphitic carbon nitride (g-C 3 N 4) nanoflakes is achieved by polyindole (PIn) without using any surfactant via in-situ chemical polymerization. The electro capacitive properties of the materials are directly related to their surface functionalities, microstructure, and interfacial interaction. Therefore, the interface engineering of g–C 3 N 4 –PIn nanohybrid is performed to improve the electrochemical activity. The optimal composition of g–C 3 N 4 –PIn nanohybrids is investigated by varying amounts of indole monomer (5, 20 and 50 mg) with a fixed weight of g-C 3 N 4 (10 mg) during polymerization. Various spectroscopic/microscopic techniques identify the as-synthesized nanohybrids before exploring their application as metal-free electrode material. In comparison (current density at 2 Ag−1), the 1:2 g–C 3 N 4 –PIn nanohybrid exhibits better electrochemical performance over the others. The specific capacitance (Cs) values are estimated as 115.8 Fg−1for 1:2 g–C 3 N 4 –PIn and 12.4, 38.7, 21.5, and 66.9 F g-1, for bare g-C 3 N 4 , pure PIn, and other two nanohybrids (1:0.5 and 1:5) of g–C 3 N 4 –PIn respectively. In this article, the 1:2 g–C 3 N 4 –PIn nanohybrid is an optimal weight ratio and advances in strategies on the metal-free and binder-free electrodes with the fast diffusion process of charges. It shows 96% cycling stability over 250 cycles. Image 1 • Surface modification of graphitic carbon nitride (g-C 3 N 4) nanoflakes with polyindole. • Electrochemical performance of materials depend on their structure and interfacial interaction. • Synergistic effect only up to a certain ratio of parental counterparts. • A metal-free electrode material for electrochemical applications such as supercapacitor. [ABSTRACT FROM AUTHOR]