Facile Synthesis and X-band Microwave Absorption Performance of Activated Carbon Materials from Palm Kernel Shell Waste

Abstract

Abstract A well-developed porous activated carbon materials were synthesized from palm kernel shell (PKS) waste through the facile carbonization process with several KOH concentration, and the microwave absorbing performance were studied in the X-band range. The XRD and EDX measurement results confirmed the transformation from crystalline structure to the amorphous structure of cellulose of PKS materials with the higher carbon content. The BET analysis measures the pore size between 2–4 nm and a specific surface area between 554–825 m2/g. All activated carbon materials show the improvement of microwave absorbing performance compared to its hydro char or raw PKS materials, with the highest minimum return loss and frequency bandwidth of -37.85 dB at 11.02 GHz and 900 MHz, respectively, for activated carbon with only KOH concentration of 10%. The porous structure of AC-based PKS is benefitted to give better impedance matching and dielectric loss capacity to enhance the microwave absorbing performance of AC-based PKS waste. This observation indicates that the activated carbon can be synthesized with a facile process from PKS waste and expands the possible utilization of AC-based PKS waste as the prospective microwave absorber materials for electronics and telecommunication devices.