Magnetic graphene oxide-nano zero valent iron (GO-nZVI) nanohybrids synthesized using biocompatible cross-linkers for methylene blue removal

• Published in: RSC advances Vol. 9; no. 2; pp. 963 - 973
• Main Authors: Mehrabi, Novin, Masud, Arvid, Afolabi, Moyosore, Hwang, Jinwoo, Calderon Ortiz, Gabriel A, Aich, Nirupam
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 08.01.2019; The Royal Society of Chemistry
• Subjects: Adsorbents; adsorption; Agglomeration; Aqueous solutions; Biocompatibility; Chemical properties; Chemistry; Contaminants; Crosslinking; energy-dispersive X-ray analysis; Ethanol; Fourier transform infrared spectroscopy; Graphene; iron; Magnetic separation; magnetism; Methylene blue; nanohybrids; Organic chemistry; physicochemical properties; Raman spectroscopy; Regeneration; scanning electron microscopy; Synthesis; thermogravimetry; transmission electron microscopy; X-ray diffraction
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/c8ra08386j

GO and nZVI have been used for removing different contaminants from aqueous solution; however, difficulty in the separation of GO, and the aggregation propensity of nZVI particles prevent them from having efficient practical applications. In this study, a green synthesis method was performed to prepare nanohybrids of GO and nZVI to provide an adsorbent with high adsorption efficiency that can be removed from aqueous solution easily by magnetic separation. GO-nZVI nanohybrids were synthesized by using biocompatible cross linkers named 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) and N -hydroxysuccinimide (NHS). The effect of the nZVI ratio in the synthesized nanohybrids was studied at three different ratios of GO : nZVI, 1 : 1, 1 : 5 and 1 : 10. SEM/EDS, HRTEM, STEM/EDS, XRD, Raman, FTIR, and TGA analyses were conducted to provide physical and chemical properties of the adsorbents. The performance of nZVI and GO-nZVI nanohybrids as an adsorbent have been studied for methylene blue (MB) removal from an aqueous solution with an initial concentration of 12 mg L −1 at adsorbent dosages of 0.1, 0.3, 0.5, and 1 mg mL −1 . Results indicated that GO-nZVI (1 : 5) provided the highest MB removal (99.1%) by using 10 mL of the 1 mg mL −1 adsorbent. After regeneration of the GO-nZVI (1 : 5) nanohybrids with ethanol, 84.3%, 67.2%, and 63.0% of MB removal were achieved in the first to third regeneration cycle. Results also showed that the GO-nZVI nanohybrids were not affected by aggregation compared to nZVI. A green synthesis method was used to prepare GO-nZVI nanohybrids to provide an adsorbent with high adsorption efficiency that can be removed from aqueous solutions easily by magnetic separation.