Flame synthesis of carbon nanoparticles from corn oil as a highly effective cationic dye adsorbent

Abstract

Carbon nanoparticles (CNP) were synthesized through flame deposition method from a sustainable corn oil precursor. The morphology, particle size, surface chemistry, thermal stability, and zeta potential of the CNP were characterized. The batch adsorption of a cationic dye, methylene blue (MB), by the CNP at various concentrations, pH, and temperatures was evaluated to investigate the CNP's efficacy in industrial wastewater treatment applications. Results revealed the excellent adsorption of MB onto the CNP. The experimental data were then fitted into isotherm models, kinetic models, and thermodynamic models, and the model parameters, constants, Gibb free energy, enthalpy, and entropy were calculated and discussed. Hydrogen bonding and strong electrostatic interaction were the main adsorption mechanism for MB adsorption by the CNP. The CNP exhibited a maximum adsorption capacity of 138.89 mg/g, indicating superior adsorption of MB dye without the need for any further purification and activation steps. The adsorption efficiency did not compromise as the solution temperature increased up to 60 °C, and it can further be enhanced under alkaline conditions. To simulate the practical and industrial use of the developed CNP in textile effluent treatment, successful experiments were conducted in continuous flow adsorption by allowing concentrated MB solution to flow through a designed fixed bed purification system with a CNP filter bed.

Keywords: Adsorption; Carbon nanoparticles; Cationic dyes; Dye removal; Flame deposition; Methylene blue.