Synthesis of Heterostructured Nanocomposite MgFe2O4/MoO3 for H2S Sensing: Experimental and Theoretical approach by DFT

Abstract

A highly selective hydrogen sulfide (H₂S) gas sensor at low temperatures is crucial. A nanocomposite of magnesium ferrite (MgFe₂O₄) and molybdenum oxide (MoO₃) was prepared through facile co-precipitation, hydrothermal, and solid-state mixing methods to enhance gas sensing performance of H₂S. The crystalline structure, surface morphology, and elemental composition were examined through X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), and X-ray photoelectron spectroscopy (XPS). A larger surface area of 54.225 m²/g with a mesoporous structure was observed for the fabricated nanocomposite MM2 (20% MoO₃). An enhanced gas sensing response of 31.18% for 7 ppm of H₂S at 135 °C was measured for MM2 nanocomposite and exhibited 1.86 times greater response than MgFe₂O₄ at 135 °C. The synergistic effect of n-n nanocomposite, combination of nanosheets with nanoparticles, and high surface area attribute to a significant improvement in sensing behavior. This article also compared the experimental data with Density Functional Theory (DFT) results.