Preparation Of Potential-responsive Magnetic Nanospheres And Its Application In Removing Toxic Metal Ions

With the expansion of modern industrial scale,toxic metal ions not only seriously polluted the environment,but also greatly endangered the health of human beings.Therefore,the development of a novel potential-responsive magnetic nanocomposites is critical for wastewater treatment.Research shows that electrochemically switched ion exchange materials couple with the magnetic material can makes the composite nanomaterials have good stability,conductivity,magnetic properties,ion exchange and electroactive properties,which is favorable for reclamation and reuse of materials.As a result,this kind of materials has received considerable attention in the field of wastewater treatment.Ferrocyanide as a kind of inorganic material,has good ion exchange properties,widely used in the treatment of toxic metal ions.It can be compounded with Fe₃O₄ magnetic material,the composite material can effectively remove toxic metal ions from the water and will not cause waste of resources and secondary pollution.In this paper,Fe₃O₄/Prussian Blue?Fe₃O₄@PB?,Fe₃O₄/Cupric Ferrocyanide?Fe₃O₄@CuFC?magnetic nanospheres were synthesized.A novel electromagnetic coupling device was designed,and its performance of removal and recovery of radioactive cesium ion were further studied.Intelligently magnetic core-shell nanospheres with potential-triggered undamaged regeneration ability and superparamagnetism for selective Cs⁺ separation and recovery are synthesized.Each nanosphere is composed of a Prussian blue?PB?shell with strong Cs⁺ affinity and a magnetic Fe₃O₄ core.The magnetic Fe₃O₄@PB core-shell nanospheres show rapid Cesium ion?Cs⁺?insertion/release kinetics,which is attributed to the good affinity of PB toward Cs⁺ and the large specific surface area.The Cs⁺ adsorbed nanospheres can be easily regenerated by simply switching potential of magnetic electrode in an electromagnetic coupling regeneration reactor.Excitingly,the Cs⁺ adsorption capacity is nearly invariable after 20 adsorption–regeneration cycles and a high regeneration efficiency over 98% is maintained in each cycle.The smart regeneration mechanism is clarified by electrochemical experiment and advanced quantum chemistry calculation.This intelligently magnetic nanospheres with potential-triggered undamaged regeneration ability should be a promising alternative materials for selective separation and recovery of metal ions from wastewater.A smart magnetic potential-responsive ion exchange nanosphere,Fe₃O₄@CuFC is successfully synthesized by coating potential-responsive CuFC on the surface of Fe₃O₄ nanosphere with superparamagetism.Such a Fe₃O₄@CuFCmagnetic potential-responsive ion exchange nanosphere shows high ion exchange capacity,excellent selectivity and rapid ion insertion kinetics,which is attributed to the sphere shape and the large specific surface area of Fe₃O₄@CuFC and good affinity of CuFC toward Cs⁺.The Cs⁺ adsorbed Fe₃O₄@CuFC can be regenerated by simply switching potential of magnetic electrode in a novel electromagnetic coupling regeneration system.Surprisingly,the capacity of the Fe₃O₄@CuFC toward Cs⁺ is nearly invariable after 20 adsorption–regeneration cycles and a high regeneration efficiency is maintained in each cycle.Moreover,the sensitive regeneration mechanism is illuminated by electrochemical experiment as well as advanced quantum chemistry calculation.It is expected to provide a versatile strategy for developing some intelligently potential-responsive nanomaterials in the controlled ion insertion/release field and designing separation devices to promote practical applications in environmental protection and resource reuse.