High performance acetone sensor based on γ-Fe2O3/Al–ZnO nanocomposites

Abstract

Ternary nanocomposites made of γ-iron oxide and aluminum-doped zinc oxide (γ-Fe2O3/Al–ZnO NCs), with different metal oxides ratio (0%–100%) were prepared through a solvothermal sol–gel process. The synthesized materials were characterized by x-ray diffraction, UV–vis spectroscopy, photoluminescence (PL), scanning electron microscope and BET analysis. Characterization results demonstrated that the ternary γ-Fe2O3/Al–ZnO NCs are mainly constituted by γ-Fe2O3 and Al–ZnO individual phases, while structural and physical properties like surface area, pore size, optical band gap, PL and electrical conductivity were deeply affected by the composition of nanocomposite. The synthesized γ-Fe2O3/Al–ZnO NCs were employed to prepare conductometric gas sensors, then their sensing performances toward acetone were also investigated. Results revealed enhanced sensing performance of nanocomposites than both pure γ-Fe2O3 and Al–ZnO phases. In particular, the γ-Fe2O3(33%)/Al–ZnO based gas sensor showed the best sensing properties, like a high response of Rair/Rgas = 29, a short response time of 3 s, in addition to an improved selectivity toward acetone versus ethanol at an operating temperature of 200 °C. Overall, ternary γ-Fe2O3/Al–ZnO NCs appear to be promising for the development of conductometric acetone sensors.