Enhanced removal of hexavalent chromium from aqueous media using a highly stable and magnetically separable rosin-biochar-coated TiO2@C nanocomposite


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Yousaf B. , Liu G., Abbas Q., Wang R., Ullah H., Mian M. M. , ...More

RSC ADVANCES, vol.8, no.46, pp.25983-25996, 2018 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 8 Issue: 46
  • Publication Date: 2018
  • Doi Number: 10.1039/c8ra02860e
  • Title of Journal : RSC ADVANCES
  • Page Numbers: pp.25983-25996

Abstract

Recently, nanosized metal-oxides have been extensively investigated for their ability to remove metal ions from aqueous media. However, the activity and capacity of these nanosized metal-oxides for removing metal ions decrease owing to their agglomeration in aqueous media. Herein, we synthesized a highly stable and magnetically separable rosin-biochar-coated (RBC) TiO2@C nanocomposite through a facile and environment-friendly wet chemical coating process, followed by a one-step heating route (pyrolysis) for efficient removal of Cr(VI) from aqueous solution. An array of techniques, namely, TEM, HRTEM, TEM-EDS, XRD, FTIR, VSM, BET and TGA, were used to characterize the prepared nanocomposite. The pyrolysis of rosin into biochar and the fabrication of Fe onto the RBC-TiO2@C nanocomposite were confirmed by FTIR and XRD examination, respectively. Moreover, TEM and HRTEM images and elemental mapping using TEM-EDS showed good dispersion of iron and carbon on the surface of the RBC-TiO2@C nanocomposite. Sorption of Cr(VI) ions on the surface of the RBC-TiO2@C nanocomposite was very fast and efficient, having a removal efficiency of similar to 95% within the 1st minute of reaction. Furthermore, thermodynamic analysis showed negative values of Gibb's free energy at all five temperatures, indicating that the adsorption of Cr(VI) ions on the RBC-TiO2@C nanocomposite was favorable and spontaneous. Conclusively, our results indicate that the RBC-TiO2@C nanocomposite can be used for efficient removal of Cr(VI) from aqueous media due to its novel synthesis and extraordinary adsorption efficacy during a short time period.