Applications of functionalized porous carbon from bio-waste of Alnus nepalensis in energy storage devices and industrial wastewater treatment

This research investigates the utility of functionalized porous carbon (FPC), derived from the waste wood of Alnus nepalensis. It demonstrates FPC's dual suitability as a versatile component for energy storage systems, specifically supercapacitors, and its impressive capacity to adsorb malachite green (MG) dye from industrial wastewater. The synthesis of FPC occurred through a controlled two-step process: initial activation of wood powder with H3PO4, followed by carbonization at 400 degrees C for 3 h in a tube furnace. To comprehensively evaluate the material's attributes, multiple analytical methods were employed: Brunauer-Emmet-Teller (BET) analysis, Transmission Electron Microscopy (TEM) imaging, X-ray Diffraction (XRD) analysis, Raman spectroscopy, and Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy. The prepared FPC exhibited desirable characteristics essential for achieving electrochemical performances and adsorption of dyes as well. TEM revealed voids within the material's structure, while BET confirmed high porosity with an active surface area of 1498 m2/g, a pore volume of 1.2 cm3/g, and a pore size of 4.6 nm featuring a harmonious presence of both micropores and mesopores. XRD and Raman spectroscopy confirmed FPC's amorphous state, and FTIR indicated oxygenated functional groups. As a supercapacitor electrode material, FPC demonstrated a specific capacitance of 156.3 F/g at 1A/g current density, an energy density of 5.1 Wh/Kg, a power density of 183.6 W/kg, and enduring cycling stability, retaining 98.4 % performance after 1000 charge discharge cycles at 3A/g current density. In terms of dye adsorption, FPC exhibited remarkable efficiency. At a pH of 10.5 for MG dye, 0.030g of FPC displayed peak adsorption capacity, removing 95.6 % of 20 ppm MG within 2 min and an even more impressive 99.6 % within 6 min. These findings confirm FPC's potential from Alnus nepalensis as an outstanding supercapacitor electrode material and a rapid, efficient adsorbent for MG removal from industrial wastewater. This research suggests promising applications in energy storage and environmental remediation.