Al3+ Impregnated Photolithograophically Fabricated Sensor Material La2-xAlxZnO4: Structural Investigation and Acute Gas Sensing Study for Hazardous Air Pollutant Gases and Humidity Assay.

The present investigation portrayed the synthesis of bare LaZn₂O₄ material and La_2-xAl_xZnO₄ material (x = 0.1–0.4 mol) by sol–gel auto combustion technique. All these materials were characterized by various prime nano characterization technique to investigate the structural and surface properties. X-ray diffraction pattern for LaZn₂O₄ material confirms the hexagonal wurtzite lattice for this material. The surface characterization and topographical parameters were confirmed from scanning electron microscopy, while the elemental composition of various concentrations Al³⁺ modified LaZn₂O₄ was confirmed from energy dispersive spectroscopy. High resolution transmission electron microscopy technique was utilized to substantiate the lattice parameter and polycrystalinity of the fabricated material. UV-DRS technique was used to validate the tuned band gap of the fabricated materials. The Brunauer–Emmett–Teller was employed to calculate total surface area of the prepared materials. The La_2-xAl_xZnO₄ is having highest surface area 85.59 m²/g and pore radius 80.85 Å. Sensor materials with varied composition of Al³⁺ (x = 0.1–0.4 mol) were fabricated by photolithographic technique having 40 s, mesh number 355. The various toxic gases such as CO, NO₂, LPG, and Acetone were investigated for varied gas concentrations. Among all sensors La_2-xAl_xZnO₄ (LZO, x = 0.2) sensor shows highest response for acetone vapors with 88.80% at lowest 60°C. The humidity sensing for the sensors shows that the sensor LZO is operational at moderate humid conditions. The rapid response recovery, reusability, thermal stability, good porosity, high surface area, operational at lower temperature is the characteristics of LZO-2 sensor. [ABSTRACT FROM AUTHOR]