Preparation of core–shell ion imprinted nanoparticles via photoinitiated polymerization at ambient temperature for dynamic removal of cobalt in aqueous solution

In this work, novel core–shell ion imprinted polymers were firstly synthesized by photoinitiated polymerization (P-IIPs) for the selective separation of Co(II) in aqueous solution. In contrast to thermal polymerization, photoinitiated polymerization exhibits faster initiation rate, only a quarter of the former, and can be performed at room temperature. Subsequently, extensive characterizations were performed using FT-IR, SEM, TEM, XRD, and TGA. Adsorption isotherm and kinetics studies were carried out in batch adsorption experiments. Furthermore, the removal of Co(II) from aqueous solution was investigated at different conditions by using P-IIPs as the adsorbent in the fixed-bed column and the parameters were discussed and optimized. The data can be well fitted by the Thomas model, offering some model parameters for process design. Compared with non-imprinted polymers, P-IIPs displayed remarkable selectivity toward Co(II). Moreover, the synthesized polymers possessed excellent desorption performance and regeneration property with a desorption efficiency up to 94.1%. P-IIPs enabled the selective extraction of Co(II) successfully from sediment samples with satisfactory recovery. The above mentioned results indicate that P-IIPs are promising high-performance, low-energy and environmentally friendly adsorbents for effectively removing Co(II) from aqueous solution.