Environmentally friendly synthesis of Fe2O3@SiO2 nanocomposite: characterization and application as an adsorbent to aniline removal from aqueous solution

Environ Sci Pollut Res Int. 2020 Mar;27(9):9181-9191. doi: 10.1007/s11356-019-07491-y. Epub 2020 Jan 8.

Abstract

Silica-based nanocomposite syntheses employ many harmful substances, which, in turn, demand the development of new synthetic environmental-friendly routes that meet the principles of green chemistry. In this work, we present a novel magnetic adsorbent, Fe2O3@SiO2 nanocomposite (Fe@SiNp), successfully obtained without surfactant, employing an electrochemical method. We characterized the nanocomposite and then applied it to remove aniline from the water medium. Characterization was carried out by vibrating-sample magnetometry (VSM), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FT-IR). The parameters to the adsorptive removal of aniline were successfully optimized, which made possible to remove 71.04 ± 0.06% (126.6 ± 2.0 mg/g) from a 100 mg/L aniline solution at pH 6 and 323 K, by employing around 50 mg of Fe@SiNp, at a contact time of 40 min. The adsorption of aniline by Fe@SiNp is a spontaneous and exothermic process according to the pseudo-second-order kinetic model (r2 = 1 at 20 mg/L aniline concentration) and the Freundlich isotherm model (r2 = 0.9986).

Keywords: Adsorption; Electrochemical synthesis; Green chemistry; Magnetic nanoparticle synthesis.

MeSH terms

  • Adsorption
  • Aniline Compounds
  • Ferric Compounds / chemical synthesis*
  • Ferric Compounds / chemistry
  • Kinetics
  • Nanocomposites*
  • Silicon Dioxide / chemical synthesis*
  • Silicon Dioxide / chemistry
  • Spectroscopy, Fourier Transform Infrared
  • Water Pollutants, Chemical*

Substances

  • Aniline Compounds
  • Ferric Compounds
  • Water Pollutants, Chemical
  • Silicon Dioxide