Preparation of high performance microwave absorbing materials based on waste peanut shells

Abstract The emergence of advanced wave-absorbing materials has led to a growing interest in biomass-derived porous carbon due to its abundant availability, low density, and eco-friendly nature. This study utilized peanut shell biomass waste to produce porous carbon material (KPS) through a two-step carbonation-activation process. We investigated the influence of varying ratios of carbonized peanut shells (CPS) to potassium hydroxide (KOH) activator on the pore structure and morphology of KPS. The comprehensive analysis of the electromagnetic parameters revealed that KPS sample achieved a remarkable reflection loss of −42.38 dB and an effective bandwidth of 2.58 GHz with the thickness of 2.5 mm when the quality ratio of CPS to activator KOH was 1:3 and the carbonation temperature was 600 °C. Notably, the KPS material demonstrated substantial specific surface area of 1037.589 m 2 g −1 and complex pore architecture, facilitating the development of conductive network and promoting multiple reflections of electromagnetic waves. This research highlighted the potential of efficiently utilizing recyclable resources to create microwave-absorbing materials that are not only simple to produce but also environmentally sustainable.