Photocatalytic Properties of Doped TiO2 Coatings Deposited Using Reactive Magnetron Sputtering

Abstract

Mechanically robust photocatalytic titanium oxide coatings can be deposited using reactive magnetron sputtering. In this article, we investigate the effect of doping on the activity of reactively sputtered TiO 2 . Silver, copper and stainless steel targets were used to co-deposit the dopants. The films were characterised using XRD, SEM and EDX. Adhesion and mechanical properties were evaluated using scratch testing and nano-indentation, respectively, and confirmed that the coatings had excellent adhesion to the stainless steel substrate. All coatings showed superhydrophilicity under UV irradiation. A methylene blue degradation test was used to assess their photocatalytic activity and showed all coatings to be photoactive to varying degrees, dependent upon the dopant, its concentration and the resulting coating structure. The results demonstrated that copper doping at low concentrations resulted in the coatings with the highest photocatalytic activity under both UV and fluorescent light irradiation.

Composition and Structure Evolution of Bi2O3 Coatings as Efficient Photocatalysts

“…The XRD patterns of Bi and Bi 2 O 3 coatings prepared at different oxidation temperature or time are displayed in Figure 1 3 were always obtained with the oxidation time ranging from 2 to 10 h. Additionally, the diffraction peaks from triclinic Bi 2 O 3 became stronger with the temperature or time raising. Consequently, the coatings composition evolved from single phase to mixed phases with prolonged time at lower temperature or heightened temperature.…”

“…Fortunately, photocatalysis technology appears as an efficient, economical, and environmental friendly technology, which can be applied in environmental remediation, as well as solar energy conversion, since it was discovered in 1972 [1][2][3]. To date, various types of semiconductor photocatalysts have been explored, especially the TiO 2 -based photocatalysts which are always being ranked as the most researched ones [4][5][6].…”

Effect of Titanium Dioxide Film Thickness on Photocatalytic and Bactericidal Activities Against Listeria monocytogenes

“…Rutile is thermodynamically stable, while anatase and brookite phases are in metastable states . Among the three crystalline phases, anatase presents the highest photocatalytic and bactericidal activity . When TiO 2 is irradiated by UV light, it produces pairs of electrons and holes.…”

Target Voltage Hysteresis Behavior and Control Point in the Preparation of Aluminum Oxide Thin Films by Medium Frequency Reactive Magnetron Sputtering

“…Reactive magnetron sputtering is realized in magnetron sputtering with a reactive gas (such as oxygen or nitrogen) introduced into the vacuum chamber, in addition to an inert working gas [8][9][10][11][12]. There are several reactive magnetron sputtering techniques, i.e., direct current reactive magnetron sputtering (DCRMS) [10], pulsed reactive magnetron sputtering (PMS) [11], radio frequency reactive magnetron sputtering (RFRMS) [12] and medium frequency reactive magnetron sputtering (MFRMS) [9], which are ordered according to the frequency of the power supply of the sputtering target.…”

“…There are several reactive magnetron sputtering techniques, i.e., direct current reactive magnetron sputtering (DCRMS) [10], pulsed reactive magnetron sputtering (PMS) [11], radio frequency reactive magnetron sputtering (RFRMS) [12] and medium frequency reactive magnetron sputtering (MFRMS) [9], which are ordered according to the frequency of the power supply of the sputtering target. The disadvantages of DCRMS are target poisoning and arc problems, and the prepared films often have large embedded particles, which renders the deposition processes hard to control and reproduce [13]; the demerits of RFRMS are the high-cost of equipment and low deposition rates [14]; thus neither of these two techniques is suitable for the preparation of high quality thin films and coatings at an industrial level.…”