Facile route for synthesis of Fe0/Fe3C/γ-Fe2O3 carbon composite using hydrothermal carbonization of sugarcane bagasse and its use as effective adsorbent for sulfamethoxazole removal

Abstract

Non-toxic mesoporous magnetic carbon composite was synthesised from hydrothermal carbonization of sugarcane bagasse with Iron (III) nitrate nonahydrate in two steps along with thermo-chemical oxidation process using sodium hydroxide. IR spectrum exposed the presence of oxygenated functional groups and FeO whereas XRD analysis revealed the availability of Fe0/Fe3C/γ-Fe2O3 at varying intensities. SEM analysis showed the spherical shaped carbon is well encapsulated with iron particles. Textural studies showed that after thermo-chemical activation intensified the surface area on composites to about 491.474 m2 g−1 thereby, promoting improved porosity on the carbon matrix. The fabricated composite showed magnetization of 32.84 emu g−1 and SMX adsorption capacity as 169.49 mg g−1. Kinetics and isotherm studies revealed that removal of SMX fitted well in Pseudo-second order and Langmuir models. The mode of interaction of SMX on magnetic carbon composites with respect to different pH was studied showing that π-π electron donor interaction (EDA), hydrophobic interaction, charge assisted hydrogen bond formation were responsible for SMX removal. The selectivity nature of magnetic composite with respect to SMX was studied in the presence of multiple pollutant. Use of magnetic carbon helps in industrialising the material to high level due to their unique property in separation and recycling. Application of hydrothermal carbonization is found to be applicable for wet solid substance thereby evolving structural carbon compound.