Well-dispersed TiO2 nanoparticles anchored on Fe3O4 magnetic nanosheets for efficient arsenic removal

• DOI: 10.1016/j.jenvman.2019.02.037
• Publication Date: 2019-02-19T03:52:48Z
• Authors: Min Deng; Xiaodong Wu; Aimei Zhu; Qiugen Zhang; Qinglin Liu
• Keywords: Nanoparticles; Adsorption; Hydrogen-Ion Concentration; 01 natural sciences; Water Pollutants, Chemical; Arsenic; Water Purification; 0105 earth and related environmental sciences

Magnetic iron-titanium binary oxide as an effective adsorbent for arsenic contaminant is a challenge primarily because of their bulk structure and agglomeration effect. Herein, a novel and uniform sandwich-like magnetic Fe3O4@TiO2 sheets were synthesized by utilizing a facile strategy involving amorphous-to-crystalline transformation and reduction in H2, to achieve dispersed anatase TiO2 nanoparticles with a small size of ∼8 nm anchored on Fe3O4 sheets. The resultant Fe3O4@TiO2 sheets nanocomposite possessing a high specific surface area of ∼89.4 m2 g-1 and available magnetic susceptibility of ∼20.0 emu g-1, significantly enhanced the photocatalytic oxidation property of arsenite and considerable adsorption capability for arsenic removal. The adsorption capacities of As(V) and As(III) with UV-assisted from adsorption experimental results were 36.36 and 30.96 mg g-1, respectively, while the residual concentrations for both As(V) and As(III) were lower than the strict limit of 10 μg L-1. Adsorption equilibriums were almost reached within 45 min. In addition, the adsorbent exhibited excellent stability over a broad pH range of 3-9 and still maintained great removal efficiency after five time regeneration cycles. Furthermore, except for silicate and phosphate, the extremely weak inhibiting influences of common co-existing ions in arsenic removal process, demonstrated that the developed magnetic Fe3O4@TiO2 sheets with unique nanostructure could be a promising efficient adsorbent for arsenic removal.