The Pb(II) ion-imprinting electrospun crosslinked chitosan nanofiber mats were fabricated by one-step electrospinning and ion-imprinting methods and their application as adsorbents for metal ions was also investigated. The resulting chitosan nanofiber mats were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and thermal gravimetric analysis (TGA). The Pb(II) ion-imprinting electrospun crosslinked chitosan nanofiber mats were used as adsorbents for the removal of Pb(II) ions from aqueous or acid solutions. The effects of pH values, contact time, content of crosslinker (glutaraldehyde) on Pb(II) ions adsorption were studied. The results indicated that the Pb(II) ion-imprinting electrospun crosslinked chitosan nanofiber mats had the highest adsorption capacity of 110.0 mg/g at pH 7. The kinetic study demonstrated that the adsorption of Pb(II) ions followed the pseudo-second-order model. The equilibrium isotherm data showed that the Langmuir model was the most suitable for predicting the adsorption isotherm of the studied system. The Pb(II) ion-imprinting electrospun crosslinked chitosan nanofiber mats had good adsorption selectivity, which illustrates the equilibrium adsorption capacity in the order of Pb(II)>Cu(II)>Zn(II)>Cd(II)>Ni(II). The Pb(II) ionimprinting electrospun crosslinked chitosan nanofiber mats were stable and had good reuse ability.

•A combined technique of ion-imprinting and electrospinning is used.•Lead-ion imprinted crosslinked electro-spun chitosan nanofiber mats were prepared.•Highest adsorption capacity for Pb(II) ions of 577 mg/g was obtained.•The nanofiber adsorbents can be recycled and reused.Herein we report a novel and high efficient lead ion-imprinted adsorbent of chitosan nanofiber mats by electrospinning of chitosan solution with Pb(II) as template and glutaraldehyde as crosslinker. The structure of the resulting nanofiber mats was characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS) and Thermal Gravimetric analysis (TGA). The equilibrium adsorption capacity for Pb(II) ions of such chitosan nanofiber adsorbents can arrive at 577 mg/g, which is two or five times higher than that of the common chitosan-based adsorbents. The kinetic study demonstrates that the adsorption of Pb(II) ions follows a pseudo-second-order model. Besides, the comparative adsorptions of Pb(II), Cu(II), Cd(II), Ni(II) and Zn(II) ions were also studied, which show the equilibrium adsorption capacity in the order of Pb(II) > Cu(II) > Cd(II) > Ni(II) > Zn(II). The nanofiber adsorbents can be regenerated under EDTA and still has equilibrium adsorption capacity of 359 mg/g for the second Pb(II) ion adsorption.Graphical abstractLead-ion imprinted crosslinked electro-spun chitosan nanofiber mats were prepared through a combined ion-imprinting and electrospinning technique, which show a very high adsorption capacity of 577 mg/g for Pb(II) ions.