Synthesis, characterization and activity of photocatalytic sol–gel TiO2 powders and electrodes

Titanium Oxide Antibacterial Surfaces in Biomedical Devices

“…Obviously, these synergistic effects, deriving from doping TiO 2 structures are not peculiar of sol-gel technology, and have hence been explored also using other technologies, as discussed below. Several examples other than those reported here can be found in literature (4,61,63,(69)(70)(71)(72)(73)(74)(75)(76)(77), and we suggest the reader refer to each of these works to have an overall idea about ongoing research studies. However, some general conclusions on this technique can be drawn.…”

“…Furthermore, the TiO 2 -coated orthodontic wires had a bactericidal effect on both strains; since one of the main causes of failure in orthodontic treatment is the development of dental plaque initiated by the adhesion of S. mutans to the tooth surface or orthodontic devices, this treatment appears of particular interest for this specific device (64). This example allows us to point out that materials other than Ti alloys can be treated in order to add a thin titanium oxide layer onto their surface: results of this sort have been achieved by other authors on different organic and inorganic substrates (4,(70)(71)(72)(73). Another advantage of using the sol-gel technique is the possibility of incorporating metal ions, nanometric clusters, and bactericidal molecules that in most cases have antibacterial properties per se, namely Ag ions/nanoparticles (61,63,(74)(75)(76), or Cu ions (69,73).…”

“…By using suitable Ti precursors, thin TiO 2 coatings, based on either conventional (59) or the Stepwise Surface process (60), can be obtained on different substrates. Surface modifications aimed at obtaining antibacterial properties using sol gel TiO 2 coatings have been realized by several research groups (12,(61)(62)(63)(64)(65)(66)(67)(68)(69)(70)(71), even if in some cases it is difficult to compare the results due to scarce homogeneity in surface preparation, chemico-physical characterization, and the selected bacteria strains and methods (this point will be further elucidated in the next section). Chun et al (64) proposed the modification of orthodontic…”

Does photoelectrocatalysis by TiO2 work?

“…4 show that sol-gel electrodes effectively decolourized reactive orange dye, whereas other studies, not reported here, showed that decolouration at the surface of thermal electrodes was much less efficient. 26 The causes of these differences and also attempts to develop electrodes that are sensitive to visible radiation 27,28 and the effects of transition metal ions 29 on PEC activity are outside the scope of this paper. However, the differences do suggest the route to technologically effective PEC may be via electrode improvements; currently much effort is focused on titania nanotube (TNT) electrodes.…”

Photoelectrocatalytic Oxidation of Cu-cyanides and Cu-EDTA at TiO2 nanotube electrode

“…PEC oxidation in which a small positive potential was applied across the photocatalytic anode can enhance the separation efficiency of photogenerated holes and electrons and has proven to be more efficient for the pollutants oxidation than the individual photocatalytic process and [14][15][16][17]. This PEC method can efficiently destroy undesirable organic compounds and can be used for disinfection in aqueous phase and remove traces of organic species that were stable and difficult to oxidize by means of conventional water treatment methods [18][19][20][21][22].…”