Photocatalytic Properties of Columnar NanostructuredTiO2Films Fabricated by Sputtering Ti and Subsequent Annealing

Abstract

Columnar nanostructured TiO2films were prepared by sputtering Ti target in pure argon with glancing angle deposition (GLAD) and subsequent annealing at 400°C for different hours in air. Compared with sputtering TiO2target directly, sputtering Ti target can be carried out under much lower base pressure, which contributes to obtaining discrete columnar nanostructures. In the present study, TiO2films obtained by annealing Ti films for different hours all kept discrete columnar structures as the Ti films deposited in GLAD regime. The longer the annealing time was, the better the phase transition accomplished from Ti to TiO2(a mixture of rutile and anatase), and the better it crystallized. In addition, those TiO2films performed photocatalytic decolorization effectively and showed a law changing over annealing time under UV light irradiation towards methyl orange, which demonstrated the potential applications for treatment of effluent.

Adsorption Kinetics of NO2 Gas on Pt/Cr-TiO2/Pt-Based Sensors

“…From the previous reports, one can anticipate an anatase to rutile transformation for undoped TiO2 at annealing temperature higher than 800 °C. However, for Cr-TiO2 coatings, this phase transformation already exists at 800 °C, which is in good agreement with the previous reports [28][29][30]. A slight shift in the reflections of TiO2 in the above X-ray diffraction patterns has been observed (Figure 2), which indicates Cr integration into the TiO2 matrix.…”

Effects of processing conditions on the physico-chemical characteristics of titanium dioxide ultra-thin films deposited by DC magnetron sputtering

“…The film annealed at 500°C has a higher transition in comparison with the film annealed at 400°C. This can be explained with the more degree of crystallinity of the resulted anatase TiO 2 film in the higher annealing temperature [13].…”

“…DC magnetron sputtering oxidation of Ti ultra-thin films, in comparison with other TiO 2 thin film production methods, such as sol-gel, ion-assisted deposition and chemical vapor deposition, is a method with more efficiency and flexibility. The various oxidizing temperatures of the Ti films, result in structures with different stoichiometry or crystallinity [8,[11][12][13][14][15].…”

Branching of Titanium Nanorods

“…It is common to grow one dimensional nanostructures using physical vapor deposition under glancing angle deposition (GLAD) conditions by taking advantage of geometrical shadowing [ 1 , 2 ]. These nanostructures take the forms of rods, springs, zigzags, and blades [ 3 , 4 , 5 , 6 , 7 , 8 , 9 ]. A key factor that makes these structures nano-sized is the limited surface diffusion that is dictated by the three-dimensional (3D) Ehrlich–Schwoebel (ES) barrier [ 10 , 11 , 12 ].…”