Utilisation of green nitrogen-doped biomass-based hierarchical porous activated carbon particles for enhancement of electrochemical energy storage performance

Abstract

Activated carbon particles were obtained from rosehip wood-based carbon precursor by chemical activation with potassium hydroxide (RHAC). After this pyrolysis process, nitrogen-doped hierarchical porous carbon was prepared by ammonia activation (N-doped RHAC). The prepared carbonaceous materials were designed as an electrode for a supercapacitor. Standard electrochemical analyses were performed. The specific capacitance (Cs) of RHAC/GCE was determined to be 25 F/g at 2.5 mV/s and 23 F/g at 0.2 A/g. In contrast, the N-doped RHAC/GCE demonstrated significantly higher Cs values of 119 F/g at 2.5 mV/s and 121 F/g at 0.2 A/g. According to CV and GCD measurements, the N-doped RHAC material exhibited approximately a fivefold increase in specific capacitance compared to the RHAC-based electrode. A specific capacitance retention rate of 94.6 % was obtained after 1000 cycles at a current density of 1.6 A/g. The surface properties and characteristics of the obtained materials were carried out by SEM, nitrogen adsorption, Raman, FTIR, EDS and XPS analyses. EDS and XPS analyses showed that N atom doping was successful. This study suggests that rosehip tree biomass-based N atom doped carbon material is suitable for supercapacitors as an electrode.