N, P and N, S dual doped carbon replicas of SBA-15 template for high performance symmetric supercapacitor
Shunmuga sundaram Shanmugam, Velu Duraisamy, Subramaniam Gokulnath, P. Sathiya, Sakkarapalayam Murugesan Senthil Kumar, M. Sathish
Abstract
Applying dual heteroatom doping strategies to synthesize carbon materials has attracted tremendous interest in improving supercapacitor performance , due to their exemplary high specific surface area (SSA), ordered porous structure, highly accessible special pores, and uniform distribution of heteroatoms in the carbon structure . In this work, we prepared highly ordered N, P and N, S dual-doped carbon (NPC/NSC) with the utilization of 2D hexagonally ordered Santa barbara amorphous (SBA-15) silica supporting material to analyze the P/S doping effect on N-doped carbon towards supercapacitor activity. The addition of minimum amounts of secondary heteroatom precursor in the N-doped SBA-15 template can significantly influence the physiochemical properties and supercapacitor performance of the resulting NPC/NSC materials. The NSC material significantly improves the surface area (951 m 2 g −1 ), good replicated porous morphology, higher doping content of N (1.61 at.%) and S (0.62 at.%), enriched pyrrolic (17.3 %) and pyridinic N (19.0 %) concentrations and higher defect sites (I D /I G = 1.06) which leads to greatly enhances capacitance performance than that of NPC. In addition, NSC effectively improves higher specific capacitance of 480 F g −1 at a current density of 2 A g −1 . Further with redox additive the specific capacitance has increased to 910 at 2 A g −1 with a power density of 22.2 kW kg −1 and higher energy of 80.9 Wh kg −1 in 0.01 M hydroquinone redox additive in 1 M H 2 SO 4 electrolyte solution .