Magnetic Cobalt Oxide Nanoparticles: Sucrose-Assisted Self-Sustained Combustion Synthesis, Characterization, and Efficient Removal of Malachite Green from Water

• Published in: Journal of chemical and engineering data Vol. 65; no. 5; pp. 2819 - 2829
• Main Authors: Mohanta, Jhilirani, Dey, Banashree, Dey, Soumen
• Format: Journal Article
• Language: English
• Published: American Chemical Society 14.05.2020
• ISSN: 0021-9568; 1520-5134
• DOI: 10.1021/acs.jced.0c00131

Designing a stable and efficient adsorbent for removal of pollutants such as dyes is of serious concern nowadays. In view of that, magnetic cobalt oxide nanoparticles (CONP) were synthesized in a multigram scale using a modified self-propagator combustion method triggered by sucrose as the fuel. The material was characterized by Fourier-transform infrared spectroscopy, X-ray diffraction, vibrating sample magnetism (VSM), scanning electron microscopy (SEM)–energy-dispersive system, high-resolution transmission electron (HRTEM), pHZPC, and Brunauer–Emmet–Teller surface area. SEM and HRTEM images confirm the presence of distinct pore channels. Room temperature VSM reveals weak hysteresis, indicating that the CONP is a soft but robust magnetic material. pHZPC was found to be 6.45. Removal of malachite green from simulated water was tested in a batch mode and found to be promising. Physiochemical parameters such as pH, contact time, dose, and temperature were optimized. The maximum Langmuir adsorption capacity was found to be 238.10 mg/g. Adsorption is best described by the Langmuir isotherm model (R 2 = 0.999) and pseudo-second order kinetics (R 2 = 0.999). Regeneration (83%) with dilute acid enables its successive use. Its magnetic nature facilitates the rapid separation of the CONP after adsorption using a hand-held magnet. Easy synthetic protocols, robustness, high removal efficiency, and reusability make the material an ideal future choice for dye detoxification.