Gas sensing capabilities of sol–gel dip-coated pure SnO₂ thin films for CO and C₃H₈ detection

This paper presents a comprehensive investigation to increase the gas sensing capability of pure tin oxide (SnO₂) film coatings while ensuring non-contamination. The SnO₂ thin-film coatings deposited on glass substrates were processed by homogeneous precipitation and sol–gel dip coating methods. Various characterization techniques, including X-ray diffraction, ultraviolet–visible spectroscopy (UV–Vis), and scanning electron microscopy were used to analyze the structural, optical, and morphological properties of the coatings. The prepared SnO₂ coatings were tested using separately two different gases, carbon monoxide (CO) and propane (C₃H₈), to assess their gas sensing capabilities. The results show a significant influence of the multilayer coating of SnO₂ on the sensing performance. Remarkably, the SnO₂ sample with three layers exhibited a high sensitivity. By enhancing the gas sensing capabilities of tin oxide films through the dip coating technique, this study contributes to the advancement of gas sensing technologies.