structural and spectroscopic insights into guinea grass derived porous carbon for electrochemical energy storage and synthesis of bis(indolyl)methane derivatives of 2-phenyl-1h-indole

Biomass valorization into multifunctional carbon materials provides a sustainable route toward clean energy and green chemical processes. in this study, megathyrsus maximus (guinea grass), an abundant lignocellulosic biomass, was transformed into porous carbon through pyrolysis followed by koh activation. the resulting material exhibited hierarchical porosity, partial graphitization, and abundant oxygen functionalities, as confirmed by xrd, bet, ftir, and microscopic analyses. a high surface area of 447 m² g⁻¹ facilitated efficient ion transport and charge accumulation, resulting in a remarkable specific capacitance of 918 f g⁻¹ at 10 mv s⁻¹ in 1 m naoh—superior to many reported biomass-derived carbons. the high capacitance, despite the modest bet area, results from synergistic mesopores, oxygenated groups, partial graphitization, and binder-free electrode design. furthermore, the carbon derived from guinea grass yielded an active solid acid catalyst that efficiently promoted the condensation of 2-phenyl-1h-indole with aromatic aldehydes to afford bis(indolyl)methanes in excellent yields (65–81%) under mild, solvent-efficient conditions. this dual-function approach demonstrates the potential of guinea grass as a low-cost, renewable precursor for both high-performance supercapacitor electrodes and sustainable heterogeneous catalysis, offering a scalable pathway for integrated energy and chemical transformation applications.