Nanostructure Dopants TiO2 Films for Gas Sensing

Abstract

Nanostructure TiO2 doped with noble metals such as (Ag, Pt, Pd, Ni) thin films were prepared by Pulsed Laser Deposition (PLD) on SiO2 and Si (111) substrates. The thin films structures were determined by X-ray Diffraction (XRD). XRD pattern shows an increase in the average size of the crystalline grains with the range (11.6-25) nm in the all film samples. The morphology properties were determined from Atomic Force Microscopy (AFM), which shows that the grain size of the nanoparticles observed at the surface depend on the type of metal dopant.TiO2 doped with 3 % Pt metal has the smallest grain size of (11.6nm ) and RMS roughness values of (28 nm). The produced thin films in this study have been exposed to 50 ppm CO gas concentration.TiO2 doped with noble metal has sensitivity of higher than pure TiO2 .TiO2 doped with Pt metal deposited on Si (111) has 23 % maximum sensitivity to CO gas with optimum operation temperature of 250°C.