Effects of KOH activation on surface area, porosity and desalination performance of coconut carbon electrodes

Abstract

Coconut carbon was activated by various concentrations of KOH to obtain carbon with different surface area and porosity, hence co-relate the effects of activation on surface area, pore size, and desalination performances of resulted activated carbons. For activation purpose, 0.05, 0.1, 0.2, and 0.5M KOH solutions were used, subsequently followed by carbonization under N2 atmosphere. The resulted surface areas were found to be 909.21, 703.47, 647.32, and 601.14 m2 g−1, respectively. Activated carbon electrodes were prepared with poly tetrafluoroethylene and carbon black, tested for electrosorption of NaCl under 1.6 V. Highest adsorption values were found to be 21, 15, 16, and 26 mg L−1 g−1 for 0.05, 0.1, 0.2, and 0.5M KOH Ac. Brunauer–Emmett–Teller and scanning electron microscopy confirmed the electrodes were porous, and the average pore size was in the range of 2.46–2.81 nm. Furthermore, Fourier transforms infrared spectroscopy spectra were used to investigate the presence of oxygen containing functional groups. The electrical double layer formation was characterized by using cyclic voltammetry.