Fabrication, Modification, and Emerging Applications of TiO₂Nanotube Arrays by Electrochemical Synthesis: A Review

Abstract

Titania nanotube arrays (TNAs) as a hot nanomaterial have a unique highly ordered array structure and good mechanical and chemical stability, as well as excellent anticorrosion, biocompatible, and photocatalytic performance. It has been fabricated by a facile electrochemical anodization in electrolytes containing small amounts of fluoric ions. In combination with our research work, we review the recent progress of the new research achievements of TNAs on the preparation processes, forming mechanism, and modification. In addition, we will review the potential and significant applications in the photocatalytic degradation of pollutants, solar cells, water splitting, and other aspects. Finally, the existing problems and further prospects of this renascent and rapidly developing field are also briefly addressed and discussed.

Characterization of Micron-Scale Nanotublar Super Dielectric Materials

“…Surprisingly, though, both techniques resulted in anodic films even thinner than those grown using the previously discussed medium film protocols (those using low fluoride concentrations). The results from these high fluoride protocols reinforced the assertions from other studies [87], [93] that higher fluoride concentrations alone are not sufficient to grow thicker films. Higher potentials are necessary to promote the fieldaided ionic transport and targeted anodic dissolution at the base of the nanotubes rather than general dissolution at the outer portions of the anodic films.…”

“…Anodizing methods for creating nanofeatured films on titanium substrates have been extensively studied under a variety of similar conditions [61], [87][88][89][90][91][92][93][94]. The varying methods differ in substrate thickness, surface preparation, electrolyte composition, electrolyte concentration, anodizing potential, and anodizing duration.…”

“…Some studies cited in the development of this research [87], [93] present general guidelines for growing longer tubes with wide ranges of voltage, concentration and time. In most cases, the need for higher applied voltages (> 60 volts) to grow thicker films during anodization is well documented.…”

“…Using guidance from the literature [87], [93], the first thick film protocol was designed as a 60 volt, 4-hour procedure. However, unlike previous titanium anodization procedures, the anodic current density plotted in Figure 39 climbed continually over the first 10 minutes to levels not witnessed before.…”

Formation of nanocomposites of platinum with nanotubular titanium dioxide

“…One can functionalize titania and TNT or enhance its initial functional (sensor, catalytic, and other) properties via its modification with metals and, in par ticular, noble metal nanoparticles (Ag, Au, Pt, Pd, their alloys) [20][21][22]. For example, the studies of cat alytic activity of nanotubular titania coated by gold nanoparticles with respect to oxygen reduction reac tion showed that it is three times as much as that for flat gold electrode [23].…”