One‐Pot Electrochemical Synthesis of Citric Acid Functionalized Iron Oxide Magnetic Nanoparticles for Congo Red Adsorption

Abstract

AbstractAzo dyes, like Congo red (CR), are persistent contaminants that cause detrimental consequences on living organisms in various habitats. In the present study, a novel and facile one‐pot citric acid functionalized iron oxide magnetic nanoparticles (Fe3O4@CA NPs) through an electrochemical method are synthesized and characterized for adsorbing CR dye present in an aqueous solution is reported. The influence of various factors on the adsorption of CR dye, namely pH of the CR solution, Fe3O4@CA NPs concentration, initial CR dye concentration, contact time, temperature, and agitation speed, are examined. The adsorption isotherms and kinetic studies for CR adsorption on Fe3O4@CA NPs are also investigated. The equilibrium results correspond well to the Langmuir isotherm having maximum dye uptake of 46.948 mg g−1, while the adsorption follows the pseudo‐second‐order kinetics model. The adsorption process appears to be spontaneous and endothermic, according to the thermodynamic parameters. The mechanism of CR adsorption on Fe3O4@CA NPs is also suggested. The synthesized nanoadsorbent shows more than 90% recyclability during five consecutive adsorption–desorption cycles. The simple and cost effective synthesis, high adsorption capacity, and recyclable nature of Fe3O4@CA NPs suggest the potential to eliminate CR from aqueous sources.