Effect of Ammonium-Based Ionic Liquid [EtOHA][BA], on the Surface Morphology of Chemically Activated Rubber Seed Shell, as a Promising Adsorbent
Critical environmental issues related to waste disposal highlight the need to convert waste into valuable products. Researchers have been focused on converting biomass into Activated Carbon (AC) for beneficial applications. This study employed a wet impregnation technique on Rubber Seed Shell (RSS) biomass, using KOH as a chemical activator and surface-functionalizing it with, Ionic Liquid (IL) Ethanol Ammonium Butyrate [EtOHA][BA]. The biomass was activated at 800°C for 3 hours under a constant N2 flow of 0.1 L/min. The Surface Area and Porosity (SAP) results indicated that higher IL concentrations increase the number of active sites on AC. The reduction in surface area and pore volume from 954.19 m²/g and 0.43 cm³/g to 689.25 m²/g and 0.26 cm³/g suggested effective IL permeation into the pores, while the Type IV isotherm trend indicates a mesoporous structure of AC. Scanning Electron Microscopy (SEM) analysis revealed the permeation of IL functionalities, and elemental analysis indicated an increase in nitrogen content, suggesting the presence of more active sites for proton attraction. The detection of N–H stretching and bending through Fourier Transform Infrared spectroscopy (FTIR) analysis confirmed the integration of ammonium functionalities, thereby enhancing the adsorption capacity of the samples. Additionally, Thermogravimetric (TGA) and Differential Scanning Calorimetry (DSC) analysis identified RSS-AC20% as the most thermally stable sample among all evaluated samples. This study presents a promising methodology for the surface functionalization of activated carbon derived from RSS utilizing [EtOHA][BA] for surface functionalization, thus improving morphology and thermal stability to make it a potential adsorbent.