Synthesis of ion imprinted magnetic nanocomposites and application for novel selective recycling of Ni(II)

Abstract The adsorption of nickel on magnetic nanomaterials is an effective way for Ni removal and adsorbent recycling, but poor selectivity is a key factor that limited the application. To enhance adsorption and selectivity of Ni(II) by magnetic nanoparticles, a ion imprinting polymer layer through free radical polymerization loaded on silylated magnetic nanoparticles (Ion imprinting CoFe2O4@MPS, referred to as IICFMPSs) were prepared. The adsorbents were investigated via FTIR, EDS, TEM, SEM, XRD, BET and VSM. Performance was evaluated on factors including pH, time, initial Ni(II) concentration and temperature. Moreover, the adsorption property, selectivity and recyclability were studied. Maximum adsorption of IICFMPSs was 41.95 mg/g, higher than some similar adsorbents. IICFMPSs exhibited excellent selectivity to Ni(II) compared with non-ion imprinting CoFe2O4@MPS (NICFMPSs). The adsorption capacity of Ni(II) by IICFMPSs just slightly declined from 22.93 mg/g to 20.34 mg/g after four cycles. Result of IICFMPSs and IICFMPSs-Ni(II)'s XPS indicated that O and N participated in complex reaction of Ni(II) which together with structure of ionic imprinting led to the special selective adsorption of Ni(II). Grafting ionic imprinting polymer layer on classical adsorbent should be a promising candidate way of cleaner production for the purification and metal ions reuse during heavy metal polluted water treatment.