Development of a reduced-graphene-oxide based superparamagnetic nanocomposite for the removal of nickel (II) from an aqueous medium via a fluorescence sensor platform

Debabrata Nandi, Indranil Saha, Suprakas Sinha Ray, Arjun Maity

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)

Abstract

Reduced-graphene-oxide based superparamagnetic nanocomposite (GC) was fabricated and applied for the remediation of Ni(II) from an aqueous medium. The as-prepared GC was extensively characterized by Raman, TEM, AFM, SEM-EDX, SQUID, and BET analyses. Quantitative immobilization of Ni(II) in an aqueous solution by the fluorescent sensor platform of GC was explored at varying pH, doses, contact times, and temperatures. The pseudo-second-order kinetics equation governed the overall sorption process at optimized pH of 5 (±0.2). The superior monolayer sorption capacity was 228mgg-1 at 300K. Negative δG0 indicated the spontaneous sorption nature, whereas the positive δH0 resulted from an increase in entropy (positive δS0) at the solid-liquid interface during the endothermic reaction. The lower enthalpy agreed with the relatively high regeneration (approximately 91%) of the GC by 0.1M HCl, because of the formation of stable tetrahedral complex. The physisorption was well corroborated by calculated sorption energy (EDR ~7kJmol-1) and the nature of the Stern-Volmer plot of the fluorescence-quenching data with reaction time. The GC played a pivotal role as a static fluorescent sensor platform (fluorophore) for Ni(II) adsorption. Magnetic property also indicated that GC could be easily separated from fluids by exploiting its superparamagnetic property.

Original languageEnglish
Pages (from-to)69-79
Number of pages11
JournalJournal of Colloid and Interface Science
Volume454
DOIs
Publication statusPublished - 5 Sept 2015

Keywords

  • Adsorption
  • Fluorescence sensing technology
  • Magnetic separation
  • Water purification

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Surfaces, Coatings and Films
  • Colloid and Surface Chemistry

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