Deposition of Nitrogen-Doped TiO2 Films on Unheated Substrates Using DC Magnetron Sputtering Technique
The optimal process conditions for preparing nitrogen-doped titanium oxide (N-TiO2) films on unheated glass slides were investigated at various nitrogen (N2) flow rates. Films were found to exhibit significant polycrystalline structure, mainly the anatase phase with pyramid-like surface morphology. The X-ray photoelectron spectroscopy spectra confirmed the presence of the N2 within the TiO2 crystal lattice, resulting in a narrower band gap and in a red shift of the absorption into the visible-light region. N-doping of the TiO2 crystal lattice changed the oxidation state of Ti from Ti+4 to Ti+3, resulting in the formation of titanium oxynitride (TiOxNy) in the films. Our films displayed an enhanced ability to degrade a methyl blue solution illuminated with visible-light at wavelengths up to 500 nm. Among the samples tested, the N-TiO2 film that was deposited at a flow rate of 25 sccm N2 was found to be the most active photocatalyst.
K. R. Wu et al., "Deposition of Nitrogen-Doped TiO2 Films on Unheated Substrates Using DC Magnetron Sputtering Technique", Applied Mechanics and Materials, Vol. 39, pp. 85-90, 2011