Cleaner production of tamarind fruit shell into bio-mass derived porous 3D-activated carbon nanosheets by CVD technique for supercapacitor applications.

ABSTRACT

This paper reported the successful preparation and characterization of bio-activated carbon nanosheets (ACNSs) synthesized from tamarind (tamarind indicia) fruits shells (TFSs) by employing Chemical Vapor Deposition (CVD) tubular furnace. The preparation of pure ACNSs and also potassium hydroxide (KOH) activated carbon nanosheets (K-ACNSs) were made through a pyrolysis process with Argon (Ar) gas as an inert gas at 800 °C for 2h 30min, followed by further purifications of K-ACNSs. The scanning electron microscope (SEM) images of ACNSs and K-ACNSs explored with and without pores respectively. The SEM micrographs also explored 3D-porous microstructure sheets with thickness around 18-65 nm. Raman spectroscopy explored crystallinity, SP2 order and graphitization at 1577-1589 cm-1. The major functional groups were also observed. The photoluminescence (PL) was analyzed for K-ACNSs materials and revealed carbon emission broad peak value at 521.3 nm. As prepared ACNSs and K-ACNSs active materials was applied for three-electrode materials of energy storage supercapacitor analysis of cyclic voltammeter for -0.4 - 0.15 V at scan rates of 10-100 mV/s. The electrochemical impedance spectroscopy (EIS) was performed with low Rct values of K-ACNSs as 0.65Ω when compared to pure ACNSs as 5.03Ω. Mainly, the galvanostatic charge-discharge test carried out in ACNSs and KCNSs materials was corresponded to 77 and 245.03 F/g respectively, with respect to 1 A/g current density. Finally, we promise that this reported novel tamarind bio-waste into conductive porous carbon nanosheets could develop future energy storage applications of biomass-derived carbons.