Synthesis of core–shell magnetic titanate nanofibers composite for the efficient removal of Sr(ii)

Abstract

We report a facile approach for the fabrication of Fe₃O₄@titanate fibers magnetic composite through a hydrothermal method and sol–gel process. The structure and morphology were characterized by X-ray diffraction (XRD), transmission electron microsphere (TEM), scanning electron microscope (SEM) and energy-dispersive X-ray analysis (EDX). Owing to the high ion exchange capacity of the functional titanate layer, the obtained core–shell structured magnetic microspheres exhibited high removal efficiency towards strontium from wastewater. The effects of contact time and Sr(II) concentration on the uptake amount of strontium were systematically investigated. The results indicated that the adsorption equilibrium can be reached within 30 min, and the maximum exchange capacity was approximately 37.1 mg g⁻¹. Moreover, the captured Sr(II) can be eluted using 5 wt% of EDTA(Na), which contributed to the reduction of waste volume. Based on the experimental results of ion exchange process and X-ray photoelectron spectroscopy (XPS), a possible adsorption mechanism was proposed. This work provided a facile approach to synthesize magnetic functional nanocomposites for wastewater treatment.