Direct synthesis of magnetic porous carbon from coconut husk and its application in catalytic degradation of p-nitrophenol by H2O2

Abstract

Coconut husk is an abundant, available and underutilized agricultural residue. In this study, coconut husk was utilized to synthesize magnetic porous carbon (MPC) via direct pyrolysis with additional iron prescusor. The properties of the obtained material were determined by X-ray diffraction (XRD), scanning electron microscopy (SEM) images, nitrogen adsorption-desorption isotherm and vibrating sample magnetometer (VSM). The results showed that magnetic particles of Fe3O4 and Fe0 were formed over the carbon base with a saturation magnetization of 5.3 emu.g-1. Simultaneous carbonization, activation, and magnetization processes improved SBET of MPC from 18 m2/g to 495 m2/g. Subsequently, the catalytic activity of MPC was explored for the oxidation of p-nitrophenol by H2O2. At 540 ppm H2O2, 0.20 g/L MPC, 99.9% p-nitrophenol (100 ppm) was decolorized after 90 min of treatment. Moreover, MPC could be easily removed from treated solutions by a magnet bar. Overall, the findings proved that the magnetic porous carbon prepared from one-step pyrolysis of coconut husk might be a promising multi-functional material due to its magnetic recoverability and efficient catalytic activity in p-nitrophenol treatment.