Interfacial engineering of ionic liquid functionalized g-C3N4/GO nanocomposite toward high-performance supercapacitors
Abstract
A novel ionic liquid-functionalized graphitic carbon nitride/graphene oxide (g-C 3 N 4 -IL@GO) nanocomposite was successfully synthesized through a facile multi step strategy. Graphitic carbon nitride (g-C 3 N 4 ) was prepared by thermal polymerization and then functionalized with a DABCO-based ionic liquid via the substitution of surface active sites with 1,4-dibromobutane and functionalized DABCO to afford g-C 3 N 4 -IL. The functionalized material was then combined with graphene oxide sheets by interfacial assembly. This approach facilitated the development of a hybrid layered nanostructure with enhanced physicochemical properties for energy storage applications. The successful functionalization and nanocomposite formation were verified by complementary structural and surface analysis methods such as (XRD), (FTIR), (SEM), (EDS), (XPS), (BET), and (TGA). The electrochemical behavior of the g-C 3 N 4 -IL@GO electrode material was comprehensively analyzed using CV, GCD, and EIS in a three electrode system. The CV curves exhibited redox features and a total charge-storage mechanism comprising of Faradaic and electric double-layer capacitance. The GCD curves showed a high specific capacitance value of 425F/g at 2 A/g with a high current processing ability and good utilization of electroactive sites with a favorable ion-accessibility in the electrode. The excellent cycling stability of the electrode with 93% of initial capacitance retained after 10,000 successive cycles demonstrated that the electrode possessed robust structural integrity and long-term electrochemical durability. The energy and power densities were calculated from the GCD curves of the three-electrode system and found to be as high as 35 Wh/kg and 549 W/kg, respectively. To sum up, these results demonstrate the synergistic effect of the g-C 3 N 4 framework, ionic liquid group and graphene oxide layer structure, which leads to fast charge transport, high reversibility, and better electrochemical performance. Thus the composite could be considered a potential candidate for supercapacitor electrodes.