Synthesis and characterisation of tamarind seed husk-derived carbon quantum dots incorporated polypyrrole nanosphere composite for energy storage applications

Abstract

ABSTRACT In this study, the green synthesis of Tamarind Seed Husk-derived carbon quantum dots (TCQDs) by using a facile one-step hydrothermal technique and Tamarind Seed Husk-derived carbon quantum dots/Polypyrrole nanosphere composites (TCQDs/PPy-NS) was synthesised by using the facile in-situ chemical polymerisation method. These results suggest that the TCQDs/PPy-NS composite electrode is a promising electrode for high-energy storage applications. The TCQDs/PPy-NS composite offers an effective supercapacitor electrode material by blending the superior electrical conductivity of TCQDs with the increased pseudocapacitive capacity of polypyrrole nanospheres (PPy-NS). The TCQDs/PPy-NS composite exhibits a specific capacity (Csp) of 400 Fg−1 at a current density (CD) of 2 Ag−1, and a solid-state flexible symmetric supercapacitor (SSC) was developed using the TCQDs/PPy-NS composite to meet an excellent power density (PD) of 1008.19 Wkg−1 at an energy density (ED) of 31.02 Whkg−1 It also demonstrated excellent cycling stability with a capacity retention and coulombic efficiency of 84.57% and 98.06% after 4000 cycles at 2 Ag−1 respectively. This remarkable flexibility and stability make the TCQDs/PPy-NS SSC device highly suitable for applications in wearable electronics and flexible energy storage systems.