Determination of the Band Gap and Intensity of Palladium/Silver Doped TiO2 Nano Particles Using Diffuse Reflectance and Photoluminescence Spectra

Abstract

The photocatalysts Pd/TiO2, Ag/TiO2 and Ag/Pd-TiO2 were prepared using the sol immobilization method. The photocatalysts were characterized by the use of diffuse reflectance spectra (DRS) and photoluminescence spectra. Analysis of Ag/TiO2 and Ag/Pd-TiO2 using diffuse reflectance spectra (DRS) indicated reduction of band gap energy from 3.2 eV to 2.7 eV for Ag/Pd-TiO2 which makes it possible for the use of sunlight as excitation energy. Photo luminescence spectra analysis carried out on the dopants of Ag/TiO2, Pd/TiO2 and Ag/Pd-TiO2 measured the intensity which gives the rate of recombination of photo-generated electron-hole pairs in TiO2. The result indicated that reduction in intensity was highest for the co-doped Ag/Pd-TiO2. This accounts for its increase in photo catalytic property. Therefore, modification of TiO2 with Ag and Pd will provide the platform for its enhanced photocatalytic performance relevant in environmental science.

Effects of chlorinated Pd precursors and preparation methods on properties and activity of Pd/TiO2catalysts

“…The band gaps of all the Pd/TiO 2 catalysts prepared were narrower than that of pristine TiO 2 , previously reported to be 3.2 eV. 26,27 The band gaps of all the catalysts synthesized were in the range 2.88-3.03 eV. In other words, the catalysts absorbed visible light of wavelength 400-600 nm, resulting in the excitation of electrons in the valence band (VB) to the conduction band (CB) with lower energy.…”

Effect of Silver Content on the Crystalline Phase and Microstructure of TiO2 Coating Deposited on Unglazed Ceramics Tile

“…The limitation of TiO2 was due to its wide bandgap (3.2 eV) and fast recombination of photogenerated electron-hole pairs [3,4]. Thus, to enhance the performance of TiO2, metal-doped such as Pt, Au, Cu and Ag were believed can improve the photocatalytic activity of TiO2 by shifting the irradiation wavelength from UV to the visible range region [5]. Silver (Ag) is among the particularly interested doping agent within the field of advanced nanotechnology.…”