Scaling Up the Process of Titanium Dioxide Nanotube Synthesis and Its Effect on Photoelectrochemical Properties

Abstract

In this work, for the first time, the influence of scaling up the process of titanium dioxide nanotube (TiO2NT) synthesis on the photoelectrochemical properties of TiO2 nanotubes is presented. Titanium dioxide nanotubes were obtained on substrates of various sizes: 2 × 2, 4 × 4, 5 × 5, 6 × 6, and 8 × 8 cm2. The electrode material was characterized using scanning electron microscopy as well as Raman and UV–vis spectroscopy in order to investigate their morphology, crystallinity, and absorbance ability, respectively. The obtained electrodes were used as photoanodes for the photoelectrochemical water splitting. The surface analysis was performed, and photocurrent values were determined depending on their place on the sample. Interestingly, the values of the obtained photocurrent densities in the center of each sample were similar and were about 80 µA·cm2. The results of our work show evidence of a significant contribution to wider applications of materials based on TiO2 nanotubes not only in photoelectrochemistry but also in medicine, supercapacitors, and sensors.

Anodization of large area Ti: a versatile material for caffeine photodegradation and hydrogen production

“…The preparation of large area TiO 2 nanostructures (TNS) is crucial as for most real-life (photo)electrochemical applications (e.g., photocatalytic air and water cleaners or hydrogen production on a big scale) materials of several cm 2 in macroscopic surface area are necessary. There are several reports that show the photocatalytic activity of TNS (in particular nanotubes) prepared via anodization of large area Ti (>1 cm 2 ); [13][14][15][16][17][18][19] however, to the best of our knowledge, there is no report on hydrogen production.…”

“…[10][11][12] Despite the great number of reports published in the last two decades regarding the synthesis and application of anodic TNT layers, only a few reports can be found on the synthesis of TNT layers on a scale larger than a few cm 2 . 10,[13][14][15][16][17][18][19] This relates to specific synthesis challenges that occur when a potential is applied to larger Ti substrates during anodization, e.g., when larger areas are anodized, the absolute current flowing between the Ti working electrode and the counter electrode is much higher than that for smaller areas. This leads to an increase in the electrolyte temperature and leads to the so-called dielectric breakdown.…”

Porous vs. Nanotubular Anodic TiO2: Does the Morphology Really Matters for the Photodegradation of Caffeine?

“…The flowing high current leads to an increase in the electrolyte temperature and subsequently a dielectric breakdown will occur [13]. To this day, only a few reports deal with the preparation of TiO 2 nanotube layers on areas >10 cm 2 [9,[13][14][15][16][17][18][19][20]. A fieldassisted dissolution of titanium supported by fluoride ions is responsible for the formation of a nanotubular structure [7].…”