Hydrothermally Synthesized Nano Ba2SnO4 Ternary Metal Oxide: A Promising Material for Enhanced NO2 Gas Sensing

In the present study, Ba₂SnO₄ nanostructures were synthesized via the hydrothermal method at 180 °C for 24 h, using 1 M BaCl₂ as the barium source and varying concentrations of SnCl₄ (0.1, 0.3, 0.5, and 0.7 M) as the tin precursor. Thick films of the resulting Ba₂SnO₄ nanomaterials were fabricated using the screen printing technique. The corresponding film thicknesses obtained for each SnCl₄ concentration were approximately 65, 58, 53 and 47 μm, respectively. The structural properties of Ba₂SnO₄ were confirmed by X-Ray diffraction and the formation of nano Ba₂SnO₄ where confirmed by transmission electron microscopy (TEM). The surface morphology and surface characteristics of fabricated material analyzed using scanning electron microscopy (SEM) while the energy dispersive spectroscopy analysis (EDS) shows the chemical composition of the prepared thick film. The fabricated thick films of various compositions were tested for different hazardous gases like Nitrogen dioxide (NO₂), Ammonia (NH₃), Hydrogen Sulphide (H₂S), Ethanol (C₂H₆O), and Methanol (CH₃OH). The thick film of Ba₂SnO₄ thick film prepared at molar concentration Ba (1 M): Sn (0.1 M) (Sample 1) shows the maximum sensitivity 69.88% to NO₂ gas at an operating temperature of 200 °C and concentration of 400 ppm. The rapid response and recovery were recorded for Ba₂SnO₄ thick film gas sensor.