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

Abstract

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. Keywords. Spray pyrolysis techniques; TiO 2 thin films; hydrogen gas response.

Nanoscale TiO2 films and their application in remediation of organic pollutants

“…Many different metals, such as Pt, Pd, Ag, Sr, Au, Ce, V, have been employed for the preparation of metal doped TiO 2 films [27,86,91,[117][118][119][120][121][122][123][124][125]; some representative studies towards their preparation are briefly discussed below.…”