Speakers
Description
Coffee-pulp-derived carbon quantum dots (CQDs) were synthesized via a hydrothermal method and systematically characterized to assess their potential for energy storage applications. Photoluminescence studies revealed tunable emission and a high quantum yield, indicating well-passivated surfaces with abundant functional groups. SEM analysis revealed a porous and fragmented electrode morphology with visible cavities, which enhances electrolyte accessibility. Electrochemical evaluation of the CQD-based electrodes exhibited nearly rectangular cyclic voltammetry (CV) profiles, achieving a maximum specific capacitance of 133 F/g at 5 mV/s. Galvanostatic charge-discharge (GCD) measurements yielded a specific capacitance of 51.5 F/g, an energy density of 10.3 Wh/kg, and a power density of 309.8 W/kg at a current density of 0.5 A/g⁻. These findings demonstrate that upcycled coffee pulp is a sustainable precursor for producing CQDs with promising electrochemical energy storage performance.
