In this work, the core-shell nanofibers of polyacrylonitrile@polystyrene (PS@PAN) with PS as core and PAN as shell were prepared initially via coelectrospinning technique. The cyano groups of PAN shell were converted into amidoxime groups to obtain surface active PS@PAN-oxime via subsequent amidoximation process. The surface morphologies, compositions and amidoximation of the coaxial nanofibers based on PS@PAN were determined by scanning electron microscope (SEM), transmission electron microscope (TEM), Fourier transform infrared spectra (FT-IR) and X-ray photoelectron spectroscopy (XPS). The proposed PS@PAN-oxime nanofibrous mats were used as absorbents for uranyl ions in aqueous solutions. The absorption mechanism and performance were investigated by electrochemical measurements. Furthermore, the quantitative measurement of uranium adsorption on nanofibers was firstly achieved by differential pulse voltammetry (DPV). The analysis of absorption experimental data revealed that uranyl ions on PS@PAN-oxime coaxial nanofibers followed pseudo-second-order model and the Langmuir isotherm. The effect of interferences with potential metal ions was examined and the recovery studies in lake water samples were also conducted. The adsorption capacity of the uranyl ions could reach 127 mg U/g. (C) 2016 Elsevier B.V. All rights reserved.