Construction of a novel ion imprinted film to remove low concentration Cu2+ from aqueous solution

[Display omitted] •Electrochemically switched ion exchange is introduced into ion imprinting.•The film possesses high recognition selectivity and regeneration for Cu2+ ion.•The obtained film exhibit obvious ion imprinting effects towards Cu2+ ion.•The removal mechanism of imprinted film is revealed. To develop a green approach to ion capturing and separation, an electrochemically assisted imprinting and elution strategy was proposed. Novel ion imprinted film (Cu2+-IIF) was synthesized by combining ion imprinting technology with electrochemically switched ion exchange technology for removal of low concentration Cu2+ from aqueous solution. Cu2+-IIF was prepared by using Cu2+ as template ion, potassium ferrocyanide as doping agent, pyrrole as cross-linker and conductor. To enhance the ability to remove Cu2+ at low concentration, adsorption and reduction were integrated. The morphologies and microstructures of samples were characterized by field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transformation infrared spectrometry and X-ray photoelectron spectroscopy. The removal ability and selectivity of Cu2+ were tested. The results show that more than 90% of Cu2+ at the concentration of 5 ppm was removed, thus meeting the requirement for direct emission. The adsorption capacity reaches 7.57 mg g−1 at initial Cu2+ concentration of 5 ppm. The selectivity factor of Cu2+ with respect to Cd2+, Zn2+ and Ni2+ was 49.27, 26.52 and 30.16, respectively. The removal capacity of Cu2+-IIF remained 95.13% after five cycles.