Abstract
Banana peel biomass was converted into activated carbon through microwave-assisted KOH activation at a constant microwave power of 800 W and a KOH/precursor mass ratio of 1:1, using activation times of 10, 20, 30, and 40 min. The influence of activation time on the morphological and textural properties of the resulting activated carbons was systematically investigated using field emission scanning electron microscopy (FESEM) and nitrogen adsorption–desorption (BET) analyses. FESEM observations revealed progressive pore development and increased surface roughness with prolonged activation, reflecting the enhanced etching effect of KOH. Samples activated for 10–20 min retained fibrous plant-cell features and exhibited predominantly microporous structures, with a maximum BET surface area of 316 m² g⁻¹ at 20 min. Extending the activation time to 30–40 min further enhanced pore development, increasing the specific surface area to 471 m² g⁻¹ while reducing the average pore diameter from 2.86 to 1.90 nm. These changes indicate progressive pore refinement and the formation of a well-developed microporous network. The results demonstrate that microwave-assisted KOH activation provides a rapid and energy-efficient approach for producing porous activated carbon from banana peel biomass, with activation time serving as a key parameter for tailoring pore characteristics and surface area for potential environmental remediation and energy-storage applications.