Silica-coated magnetic Fe3O4 nanoparticles as efficient nano-adsorbents for the improvement of the vapor-phase adsorption of benzene

Abstract

This study focused on the preparation of silica-coated Fe3O4(Fe3O4@SiO2) for the improvement of the vapor-phaseadsorption of benzene. The Fe3O4@SiO2 was prepared via theco-precipitation method, while its characterization was carriedout using FT-IR, SEM and BET surface area analyses. Theexperimental parameters were evaluated for the vapor-phaseadsorption of benzene using response surface methodology(RSM). The Fe3O4@SiO2 adsorbed 197.50 mg g-1 of the vaporphase benzene under the following optimum conditions: 39.93min residence time, 13.57 mg l-1 initial benzene concentrationand 26.87°C temperature. The vapor-phase adsorptionmechanism of benzene on the Fe3O4@SiO2 was clarified byinvestigating the isotherms including Dubinin-Radushkevich(D-R), Freundlich and Langmuir, and the experimenatal datawere well fitted to the D-R model. The vapor-phase adsorptionkinetics of benzene on the Fe3O4@SiO2 was clarified byinvestigating the kinetics such as pseudo first-order (PFO)model and pseudo second-order (PSO) model, and theexperimantal results obeyed the PSO model. This studydemonstrated the application potential of magneticFe3O4@SiO2 as promising low-cost nano-adsorbent.