SYNTHESIS OF ZN DOPED MAGHEMITE BY WET CHEMICAL APPROACH FOR POTENTIAL DESULFURIZATION STUDY OF PAKISTANI DIESEL FUEL

Abstract

Maghemite (γ-Fe₂O₃) nanoparticles and Zn-doped maghemite nanomaterials were synthesized with controlled size to investigate the influence of Zn²⁺ incorporation on structural, magnetic, and catalytic properties. X-ray diffraction confirmed the formation of a single-phase cubic spinel structure with successful Zn substitution, accompanied by lattice distortion and variation in crystallite size. Magnetic measurements revealed superparamagnetic behavior for all samples, with a gradual decrease in saturation magnetization due to cation redistribution and weakening of Fe³⁺–O–Fe³⁺ superexchange interactions upon Zn doping. Morphological analysis indicated quasi-spherical nanoparticles with nanoscale aggregation.

The catalytic performance was evaluated via oxidative desulfurization of diesel using H₂O₂ as an oxidant. Zn doping significantly enhanced sulfur removal efficiency, reaching up to ~65%, attributed to increased defect density, improved redox activity, and enhanced adsorption of sulfur compounds. Furthermore, the catalysts demonstrated efficient magnetic recovery and reusability. The study establishes a clear structure property performance relationship, highlighting Zn-doped maghemite nanoparticles as significant, efficient, and recyclable nanocatalysts for environmental remediation applications.