Influence of oxygen flow rate on photocatalytic TiO2 films deposited by rf magnetron sputtering

Abstract

Titanium dioxide (TiO 2 ) thin films having anatase (1 0 1) crystal structure were prepared on nonalkali glass substrates by rf (13.56 MHz) magnetron sputtering using a TiO 2 ceramic target under various oxygen partial pressures. At a fixed substrate temperature of 400°C and total gas pressure of 1 Pa after 3 h deposition. Effects of oxygen partial pressure on the structural, surface morphology, and photocatalytic activities of the TiO 2 thin films were investigated. We performed both photoinduced decomposition of methylene blue (MB) and photoinduced hydrophilicity under UV light illumination. The XRD patterns exhibited a broad-hump shape indicating the amorphous structure of TiO 2 thin films. The results showed that when the [O 2 /(Ar ? O 2 )] flow rate increased to 50%, the photoinduced decomposition of MB and photoinduced hydrophilicity were enhanced. The water contact angle after 9 min UV illumination was approximately 4.5°, and the methylene blue (MB) solution decomposition from 12 down to 3.34 l mol/L for 240 min UV irradiation.

Study on dynamic scaling of morphological evolution of TiO 2 film deposited with different O 2 /Ar flow ratio

“…From Fig. 1, it can be seen that all surfaces of TiO 2 films consist of the structure of the island [36]. For TiO 2 films with O 2 /Ar<6/14, the surface islands display the small size and large density.…”

A Review on the Pathways of the Improved Structural Characteristics and Photocatalytic Performance of Titanium Dioxide (TiO2) Thin Films Fabricated by the Magnetron-Sputtering Technique

“…Many materials have been used as substrates in magnetron sputtering, including organic materials (cotton fabrics [31] and polycarbonate [18,32]), inorganic materials (glass [16,33,34] and The gas pressure inside the chamber should not be very low in order to allow a collision between electrons and some atoms before the electrons hit the anode. If the gas pressure is very high, the electrons will neither reach enough velocity nor achieve enough energy in order to form new ions or excited species in the collisions.…”

“…Many materials have been used as substrates in magnetron sputtering, including organic materials (cotton fabrics [31] and polycarbonate [18,32]), inorganic materials (glass [16,33,34] and quartz [35,36]), metals (wafers of alumina (Al 2 O 3 ) [37] zinc oxide (ZnO) [38], and stainless steel [39]), and minerals (sapphire [5]). Since the transmittance of PTFs affects the photocatalytic efficiency, materials such as glass and quartz are widely used as substrates due to their high transmittance.…”

“…Sputtering power is an important parameter for fabricating TiO 2 films via RF [33,[55][56][57] and DC [58] sputtering. The crystal phase of TiO 2 , which affects photocatalytic activity, strongly depends on the sputtering power used [34,[58][59][60].…”

Effect of Argon-Oxygen Mixing Gas during Magnetron Sputtering on TiO2 Coatings

“…Dense coating provides very low permeability for electrolytes to establish an ionic conduct. The decrease in current density can be ascribed to the compact surface structure [32] and improved adhesion after decrease in oxygen partial pressure; at a lower oxygen flow rate, the nature of the substrate and oxygen flow can be an important factor influencing the quality of the coating [33], thereby reducing solution penetration and consequent localized corrosion. According to the corrosion surface, it was concluded that, after immersion for a period, the failure of the coatings could be ascribed to the micropores in the surface of coatings [34].…”