Effects of chemical impregnation agents on the characterisation of porosity and surface area of activated carbon prepared from sago palm bark

Abstract

Unprocessed sago palm bark (SPB) is a material that has been newly utilised for preparations of activated carbons (AC), using physicochemical activation techniques comprising dual carbonisation and activation phases. Activations have been conducted utilising three agents: Sulphuric acid (H2SO4), potassium hydroxide (KOH), and zinc chloride (ZnCl2). Characterisations of the porosities of AC preparations were performed using N2 adsorption-desorption to ascertain BET and micropore surface areas as well as micropore volumes and pore-size distributions. Existing groups on the AC surfaces were resolved using Fourier Transform Infrared Spectroscopy (FTIR) analyses. The morphologies of the activated carbons were assessed via scanning-electron microscopic methods (SEM) combined with energy-dispersive X-ray spectroscopic techniques (EDX). The maximal surface areas (1639.34 m2/g), pore volume (0.649 cm3/g), micropore volume (0.335 cm3/g), and micropore surface area (1,148.58 m2/g) of the prepared AC using sago palm bark were discovered at activation temperatures of 700oC and with chemical impregnation ratios of 1.51/ zinc chloride to precursors. In the instance of KOH and H2SO4 utilisation, the surface areas of the AC preparations corresponded to 970.38 m2/g and 630.73 m2/g with pore volume of 0.458 and 0.196 cm3/g, respectively.