Using Deep Eutectic Solvent for Conjugation of Fe3O4 Nanoparticles onto Graphene Oxide for Water Pollutant Removal

Abstract

Deep eutectic solvents (DESs) have emerged as a substitute for ionic liquids with lower cost and enhanced biodegradability. The most common class of DES refers to a mixture of a quaternary ammonium or phosphonium salt and a hydrogen bond donor (e.g., carboxylic acid) with a melting point lower than that of individual components. DESs have recently shown promise for surface modification of graphene oxide (GO) nanosheets with different functional groups. We hypothesize that such surface functionalization of GO (and other carbon nanomaterials) with DESs can provide a new route to conjugate metallic nanoparticles onto GO surfaces (and similar). Here, we used a typical DES, based on choline chloride and urea, for the conjugation of presynthesized Fe<sub>3</sub>O<sub>4</sub> nanoparticles onto GO nanosheets at different GO:Fe<sub>3</sub>O<sub>4</sub> ratios. Physicochemical characterization not only confirmed the ability of DES to prepare DES/GO-Fe<sub>3</sub>O<sub>4</sub> nanohybrids successfully, but also evidenced the influence of DES on the homogeneity and size distribution of Fe<sub>3</sub>O<sub>4 </sub>nanoparticles in these nanohybrids. DES/GO-Fe<sub>3</sub>O<sub>4</sub> nanohybrids can perform better than both GO and Fe<sub>3</sub>O<sub>4</sub> as adsorbents for organic dyes (methylene blue, MB) and heavy metals (Lead (II)). However, depending on the contaminant type, the contaminant removal performance varied differently for DES/GO-Fe<sub>3</sub>O<sub>4</sub> nanohybrids with different ratios.

Amine-Based Deep Eutectic Solvents for Alizarin Extraction from Aqueous Media

“…They are better than ILs in terms of cost, more environmentally friendly, easy to manufacture, have equivalent or better physiochemical characteristics, and are rich in hydrogen and ionic bonding [21][22][23]. Low melting points and vapor pressures, in addition to excellent solubility, biodegradability, and thermal and chemical stability, are all common characteristics of DESs [23][24][25]. These characteristics explain why DESs have recently become more widely used in a variety of sectors [26].…”