Hybrid Graphene Oxide/Ion-Imprinted Polymer via Single-Step Grafting-Imprinting for High-Performance and Selective...

The increasing release of Cu(II) into aquatic environments has intensified the demand for efficient and selective removal strategies. Although adsorption is widely applied for Cu(II) removal, its performance is often constrained by limited accessibility and low selectivity of active sites. In this study, a hybrid ion-imprinted polymer was synthesised via a single-step grafting-imprinting-polymerisation (SGPI) strategy, enabling the formation of a surface-oriented imprinted polymer layer on a functionalised graphene oxide support (GO/MPS). 4-vinylpyridine (4VP) was employed as the functional monomer to promote specific Cu-N coordination and facilitate binding-site formation. The resulting GO/MPS@IIPs-Cu(II) achieved an adsorption capacity (Qmax) of 256 mg g^-1, together with faster adsorption kinetics relative to bulk IIPs-Cu(II). The material also demonstrated improved selectivity for Cu over competing ions (Co, Fe, and Ba), as well as satisfactory reusability, maintaining extraction efficiencies above 98% after eight adsorption-desorption cycles. These findings demonstrate that the SGPI strategy enables a more organised distribution of imprinted binding sites, thereby improving their accessibility and promoting a synergistic combination of high adsorption capacity, rapid kinetics, selectivity, and reusability. This approach establishes a robust platform for the development of advanced hybrid ion-imprinted polymers for the selective removal of metal ions.