Facile synthesis of magnetic high-efficiency renewable nanosorbent for recyclable adsorption of Cu²⁺

This study focuses on the synthesis and characterization of recyclable nano-adsorbents of magnetic nanocomposites (Fe₃O₄@ZnO-RGO). The Fe₃O₄ nanoparticles were used as magnetic responders, ZnO coated on the surface of Fe₃O₄ not only captured Cu²⁺ but also prevented the oxidation of Fe₃O₄, and reduced graphene oxide (RGO) acted as Fe₃O₄@ZnO carrying platform could effectively adsorb Cu²⁺. The physical and chemical performance characterization suggested that the nano-adsorbents had stable structure, good hydrophilicity, and magnetic properties. Furthermore, the research results on adsorption performance indicated that the Fe₃O₄@ZnO-RGO had high adsorption properties for Cu²⁺, and the adsorption rate could reach more than 98%. The adsorption process conformed to the Langmuir model and second-order adsorption kinetics, and the adsorption of Cu²⁺ was mainly chemisorption, accompanied by physical adsorption. In addition, because of the special magnetic response performance, Fe₃O₄@ZnO-RGO could be quickly separated from the solutions for cyclic adsorption so as to avoid secondary pollution. This provided a valuable idea for the effective development of clean and efficient Cu²⁺ adsorbents, and the Fe₃O₄@ZnO-RGO had great application potential in the field of Cu²⁺ wastewater treatment.