Synthesis of activated carbon from Salacca peel using hydrothermal carbonization and microwave assisted chemical activation as promising supercapacitor's electrode

Abstract

Activated carbon is a highly porous material that has been used as electrodes for batteries, symmetric, and asymmetric supercapacitors. In this study we utilize salacca peel as a precursor to synthesis activated carbon (AC) using hydrothermal carbonization (HTC) and microwave assisted chemical activation method. The HTC was done at 225°C, 50 bar for 5 h using citric acid as a catalyst. The obtained hydrochar (HC) was furthermore impregnated using KOH as activating agent at various HC to KOH mass ratio (1:2, 1:3, and 1:4). The activation was done under microwave radiation of 700 Watt for 8 min. The obtained AC samples were characterized using scanning electron microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and methylene blue adsorption. The best AC with ratio 1:4 was furthermore tested as nickel ion's capacitor electrode. The electrochemical characteristics (cyclic voltammetry) were measured by using half-cell test pouch with nickel oxide as a reference electrode and 6 M KOH as electrolyte. The results obtained showed that AC from salacca peel gave better performance compared to commercial AC.