Auto ignition assisted synthesis of magnetic CaFe2O4: Exploring role of fuel molecule and amplest dye dismissal

Abstract

The present work explores the pioneering use of different fuels for the synthesis of CaFe2O4 (CF) nanopowder through auto-ignition synthesis (AIS) with potential application in the acid fuchsine (AF) dye removal. The results showed significant alternation in structure, morphology, and magnetic properties depending on fuel type. The morphology of the CaFe2O4 nanopowders changed from a rock-like appearance for dextrose to a porous, thick-walled network structure for sucrose. All synthesized particles showed superparamagnetic behavior, with a crystallite size of 9 nm to 16 nm. The different adsorption process parameters, including the solution pH, adsorbent amount, and contact time, were studied and optimized. The Langmuir isotherm well explains the adsorption of AF, and the maximum monolayer capacity of CF-dextrose, CF-xylitol, CF-sorbitol, and CF-sucrose was found to be 788, 1024, 1125, and 1297 mg/g, respectively. The pseudo-second-order (PSO) kinetic model describes the adsorption data and the value of rate constant (k2 = 2.36E-05 for CF-dextrose, 3.11E-05 for CF-xylitol, 2.70E-05 for CF-sorbitol, and 5.36E-05 for CF-sucrose) explain fast adsorption process. Furthermore, the CF nanopowder exhibits better regeneration and reusability capacity after multiple consecutive cycles, and magnetic separation aptitude makes it more convenient to isolate the adsorbent after the adsorption process.