Proceedings of International Conference on Applied Innovation in IT  ·  2026/06/12  ·  Vol. 14  ·  Issue 4  ·  pp. 593–600
Analysis of Titanium Doping Effects on Structural, Optical and Gas-Sensing Properties of Cobalt Oxide Nanostructured Thin Films
Maab Falah Hasan, Muthanna Fakhri Allawaia, Abdul-Lateef Abdul-Jabar, Muhaned Zaidi, Dalia Akram Mahmood and Muhannad Jadan
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Abstract
This study investigates the role of Ti doping on the properties of Co₃O₄ nanostructured thin films deposited via chemical spray pyrolysis on glass substrates at 400 °C. X-ray diffraction analysis confirmed a polycrystalline spinel cubic structure with a predominant (220) orientation. Crystallite size increased from 12.91 nm for undoped films to 24.13 nm for 4% Ti-doped samples, indicating enhanced grain growth. Atomic force microscopy revealed reduced surface roughness and particle size with Ti incorporation, suggesting improved film uniformity. Optical measurements demonstrated high visible transmittance (85.5–80.6%) and a bandgap narrowing from 2.68 to 2.58 eV, attributed to defect-state formation within the band structure. Additionally, absorption and extinction coefficients varied with doping concentration, while the refractive index exhibited a decreasing trend. Gas sensing tests toward NO₂ at 100 °C showed a progressive sensitivity decline with increasing Ti content, implying that doping adversely affects the sensing response. Overall, these findings indicate that Ti incorporation systematically tailors the structural, morphological, optical, and gas-sensing characteristics of Co₃O₄ thin films.
Keywords
Co3O4 Chemical Spray Pyrolysis Titanium Doping Thin Films Structural Properties Optical Band Gap NO2 Gas Sensing
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