Solar-Light Photoamperometric and Photocatalytic Properties of Quasi-transparent TiO₂ Nanoporous Thin Films

Abstract

Transparent photocatalytic surfaces are of ever increasing importance for many applications on self-cleaning windows and tiles in everyday applications. Here, we report the formation and photocatalytic testing of a quasi-transparent thin and nanoporous titania films deposited on glass plates. Sputtered Ti thin films were anodized in fluoride-ion-containing neutral electrolytes to form optically semitransparent nanoporous films, which transformed to be completely transparent after thermal annealing. The nanoporous films were studied at different stages, such as before and after anodization, as well as after thermal annealing using scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV-vis and Raman spectroscopy. It was observed that anodization at 20 V of high-temperature deposited titanium films resulted in regular nanopore films with pore diameters of 30 nm. Structural investigations on the transparent nanopore arrays reveal the presence of anatase phase TiO(2) even after annealing at 500 °C, which was confirmed by XRD and Raman spectroscopy measurements. The solar-light induced photocatalytic decomposition of stearic acid and photoconductivity characteristics of these nanoporous thin films are also presented.

Nano photo scouring and nano photo bleaching of raw cellulosic fabric using nano TiO2

“…It is known that generated electrons-holes pairs by light exposed TiO 2 can cause photo catalyst degradation of fatty acids including stearic [53] and oleic acid [54]. Negative electrons reacted with oxygen and produced superoxide anion radicals.…”

“…Before can attack to the waxes and other impurities and decompose them to result the lower contact angle [53,54].…”

Preparation and application of poly(zwitterionic ionic liquid) to enhance the photocatalytic activity of TiO2

“…The photocurrent of photocatalyst is very important to the photocatalytic activity and mechanism [48,49]. After absorbing the light energy, some electrons of TiO 2 could overstep the barrier of the band gap of the semiconductor.…”

A high-performance nonenzymatic piezoelectric sensor based on molecularly imprinted transparent TiO2 film for detection of urea

“…It is wellknown that the properties and performance of TiO 2 partly depend on its crystallinity and morphology (Li et al, 2009). Currently, the highly ordered transparent TiO 2 nanotube arrays have attracted considerable scientific interest in such fields as solar energy conversion, electrochromic device, antireflection coating and selfcleaning applications because the arrays possess highly active surfaces with a large surface to volume ratio, aligned tubular nature, high transparency and photocatalytic activity (Ji et al, 2010;Berger et al, 2009;Mor et al, 2005). Still, the photocatalysis of transparent TiO 2 nanotube lacks selectivity due to the nature of hydroxyl radicals or holes generated in photocatalytic oxidation, which will limit its application (TranT.…”