Ultrahigh adsorption capacity of starch derived zinc based carbon foam for adsorption of toxic dyes and its preliminary investigation on oil-water separation

A novel starch derived zinc carbon foam-like (Zn-CFst) material was synthesized and applied for the adsorption of different dyes and oil-water separation. Zn-CFst was characterized by XRD, FTIR, BET, TGA, SEM, TEM and XPS analysis. The adsorbent exhibited an ultra-high adsorption capacity towards Crystal Violet (25000 mg/g), Malachite Green (1200 mg/g) & Congo Red (1428.57 mg/g) and high absorbing capacity towards Castrol 2T (2937%) and Gear oil (2375%). Evidently, Zn-CFst shows excellent results which fitted with Langmuir isotherm and follows the pseudo-second order kinetic model. BET analysis indicated the high mesoporous nature of the sample with an average pore diameter of 31 angstrom. The instrumental analysis of XPS and FTIR have demonstrated the significant role played by Dipole-dipole H-bonding, Yoshida H-bonding, n-pi interaction and pi-pi interaction for the adsorption of experimented cationic and anionic dye molecules. The experimental results indicate that Zn-CFst can be reused after many cycles without the reduction in their efficiency both in adsorption and oil-water separation. (C) 2018 Elsevier Ltd. All rights reserved.