The photocatalytic properties of amorphous TiO2 composite films deposited by magnetron sputtering

Abstract

The preparation of amorphous TiO 2 film coupled with various metaloxide semiconductors and their photocatalytic activities evaluated by photodegradation of methylene blue and rhodamine B aqueous solution are briefly reviewed. The proposed photoreaction mechanism of the amorphous composite semiconductor and the differences between amorphous TiO 2 -based films and crystalline TiO 2 photocatalytic materials in terms of preparation and usage are addressed. The inactive intrinsic amorphous TiO 2 film coupled with various metal oxides were found to gain high photocatalytic activity. These dopants induce forming new energy levels in the band gap of TiO 2 to enhance the charge separation of the photoinduced electrons and holes and extend the light absorption of TiO 2 -based photocatalytic films into the visible region. In addition, two different effects of coupling metal oxides have been proved: the introduction of oxides of W, Cr, V, Ag, and Mo can significantly increase the photo-reactivity of amorphous TiO 2 film, while the combination of oxides of Zr, Sn, Sb, Cu, Ta, Fe, and Ni cannot affect the inactivity of pure amorphous TiO 2 film.

Preparation of photocrosslinked sol-gel composites based on urethane-acrylic matrix, silsesquioxane sequences, TiO2, and Ag/Au Nanoparticles for use in photocatalytic applications

“…When the electrons and holes reach the surface, these react with adsorbed molecules (e.g., water, molecular oxygen) and trigger the production of very reactive radicals (OH•, O 2 • − ), which are responsible for the degradation of organic compounds into CO 2 and H 2 O . According to these results, it was reasonable to hypothesize that the short‐range of TiO 2 molecular arrangement in amorphous hybrid films could induce a similar basic energy band structure of crystalline TiO 2 . Thus, the band theory of crystalline TiO 2 might be applicable to amorphous TiO 2 .…”

Antibacterial activity of thin films TiO2 doped with Ag and Cu on Gracilicutes and Firmicutes bacteria

“…It is known that transition metals (W, V, Ag, Cu etc.) or non-metals (S, C, N ) doped TiO has a lower band gap than pure TiO and can be used to increase the production of reactive oxygen species (ROS) under visible light irradiation in solutions containing undesired pollutants Fujishima et al (2008), Huang et al (2012). Doped with silver, TiO nanoparticles (NPs) prepared by sol-gel technique were successfully applied for deactivation of different microorganisms (Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus).…”

“…According to Zhu et al (2013), Wu et al (2014), Cu as an essential trace element participating in a variety of metabolic activities in living organisms, might be a more effective antimicrobial agent than Ag due to its low cytotoxicity. According to Norambuena et al (2016), amongst metals with antibacterial properties, copper has shown superior in vitro antibacterial performance while maintaining an acceptable cytotoxicity profile. A thin film containing copper could prevent early formation of biofilm which limits periprosthetic infections.…”

High-throughput evaluation in nitrogen doping of amorphous titanium dioxide

“…Titanium dioxide has been utilized for many years in a variety of applications, including pigmentation, a protective chemical in sunscreen , water treatment , air purification , deodorization, and sterilization . One of the most exciting attributes of TiO 2 is its photocatalytic ability.…”