Green Synthesis of Ni/Fe₃O₄/rGO Nanocomposites for Desulfurization of Fuel

The growing need for cleaner air is gaining a lot of attention, and therefore, the removal of organosulfur compounds from fuel with a concentration less than 15 ppm is becoming the need of the hour. To fulfill this expectation, we have synthesized an emergent class of magnetic hybrid nanomaterials (Fe₃O₄/rGO and Ni/Fe₃O₄/rGO) through a sol-gel-assisted green synthetic technique that shows remarkable adsorptive desulfurization of dibenzothiophene (DBT). The structural feature of the magnetic nanomaterial was identified through various characterization techniques like PXRD, FTIR, Raman, XPS, TGA, BET, SEM, and TEM. The magnetization of Ni/Fe₃O₄/rGO confirmed that the adsorbents performed well in magnetic separation. Further, doping with various concentrations of Ni enhances its magnetization, thereby making the recovery of nanocomposites easy, eco-friendly, and inexpensive with the help of an external magnet. In contrast to an undoped nanocomposite, Ni-doped Fe₃O₄/rGO exhibits superior properties. Also, Ni-doped Fe₃O₄/rGO shows enhanced desulfurization with an effective removal efficiency of 73% as compared with a pristine nanocomposite (45%). This is because as the doping concentration of Ni metal was increased, active Lewis acid sites were remarkably increased which were favorably available for the transfer of lone pair electrons on S atoms or π-electrons in the aromatic ring of thiophene to form strong S-Ni bonding or π-complexation. With regard to academic, industrial, and environmental considerations, Ni/Fe₃O₄/rGO is found to be a promising adsorbent and can be the best replacement for adsorptive desulfurization due to its relatively high adsorption capacity, improved magnetization, and simple magnetic separation efficiency.