Synthesis and Characterisation of Nanocomposites of TiO₂ and MgAl₂O₄ for Gas Sensing Applications

In this study, a conventional mixed oxide method was used to prepare nanocomposites of titanium dioxide and magnesium aluminate samples. The synthesis process of a low concentration of posttransition metal oxide like TiO2 with pre-transition metal oxides like MgO and Al₂O3 and its gas sensing behaviour were investigated. The present work focuses on applying different nanocomposite samples of (TiO2) x and MgAl₂O₄ (at x = 0 magnesium aluminate namely MA; x = 0°25 and 0.75 N namely MAT0.25 and MAT0.75 at 4 and 10 wt% of TiO2 in MgAl₂O₄ respectively and TiO₂ namely T) for gas sensing applications (O₂, CO and H₂ gases). The composite samples were characterized by their X-ray diffraction pattern, Fourier transform infrared spectroscopy, a particle size analyzer, X-ray fluorescent spectroscopy, scanning electron microscopy, ultraviolet visible spectroscopy, and Brunauer–Emmett–Teller methods. The response to changes in gas pressure (from 0.5 to 2 bar) was quantitatively studied in all samples (MA, MAT0.25, MAT0.75 and T) at different operating temperatures from 300 to 600 K. All samples showed a fast and improved gas response at different operating temperatures. Moreover, it was observed that the gas response of the composite sample, MAT0.75 increased by 11% more than the pure titanium sample at an operating temperature of 360 K, on the passage of O₂ gas.