Investigation the Influence of Calcination Temperature on Structural, Electrical and Gas Sensing Properties MnO<sub>2</sub> Thick Films

Metal oxide nanoparticles are widely used in various fields, including catalysis, sensing, energy storage, and more. Manganese dioxide (MnO 2 ) is a promising material for gas sensors due to its sensitivity to various gases, including oxidizing and reducing gases. The calcination temperature affects their size, crystallinity, surface area, and other properties. In the present research work, the influence of calcination temperature on the structural, electrical and gas sensing properties of MnO 2 nanoparticles or nanopowders was investigated. The MnO 2 nanopowder was calcinated at 200, 400, 600, and 800 °C in a muffle furnace for 4 hours. After that, using the calcinated powder of MnO 2 , the thick films were prepared using the standard screen printing technique. The structural characterizations were investigated using SEM, EDS, and XRD. It has been found that as the calcination temperature is increased, the electrical, structural, and gas-sensing properties of MnO 2 change. The prepared thick films calcinated at 200, 400, 600, and 800 °C are labeled as samples 1, 2, 3, and 4, respectively, in this paper. It has been found that sample 4 shows maximum resistivity, a more specific surface area, a smaller crystallite, and a maximum gas response to H 2 S gas. The maximum sensitivity was found to be 76.32% to H 2 S gas at operating temperature 120 °C. The response and recovery time was also found quickly.