Nanocrystalline Pt-doped TiO2 thin films prepared by spray pyrolysis for hydrogen gas detection

• Published in: Bulletin of materials science 2014-05, Vol.37 (3), p.425-432
• Main Authors: Patil, Lalchand A, Suryawanshi, Dinesh N, Pathan, Idris G, Patil, Dhanashri G
• Format: Article
• Language: English
• Subjects: Ammonia; Aqueous solutions; Chemistry and Materials Science; Engineering; Ethanol; Materials Science; Platinum; Spray pyrolysis; Substrates; Thin films; Titanium chlorides; Titanium dioxide
• ISSN: 0250-4707; 0973-7669
• DOI: 10.1007/s12034-014-0705-y

Nanostructured pure and Pt-doped TiO 2 thin films were prepared by chemical spray pyrolysis technique. Aqueous solution of TiCl 3 ·6H 2 O (0·01 M) was chosen as the starting solution for the preparation of pure TiO 2 thin film. Aqueous solutions of PtCl 6 ·6H 2 O (0·01 M) and TiCl 3 ·6H 2 O (0·01 M) were mixed in volume % of 1 : 99, 2·5 : 97·5 and 5 : 95 respectively to obtain Pt-doped TiO 2 thin films. The solutions were sprayed onto quartz substrate heated at 350 °C temperature to obtain the films. These thin films were fired for one hour at 550 °C. The sensing performance of these films was tested for various gases such as LPG, H 2 , CO 2 , ethanol, NH 3 and Cl 2 (1000 ppm). The Pt-doped TiO 2 (1 : 99) was observed to be most sensitive (572) to H 2 at 400 °C with high selectivity against other gases. Its response time was short (10 s) and recovery was also fast (14 s). To understand the reasons behind the gas-sensing performance of the films, their structural and microstructral properties were studied using X-ray diffraction and electron microscopy (FE–SEM and TEM), respectively. Thicknesses of all these samples were determined using Surface Profiler. The results are interpreted.