Optical fibers modified by nanostructured photocatalytic layers with high activity in visible spectrum

Sponsor: Ministry of Education, Youth and Sports of the Czech Republic

Co-principal investigator: Vlastimil Matějec, Ph.D.

Members:  Ivo Bartoň, MSc.; Miloš Hayer, Ph.D.; Ivan Kašík, Ph.D.; Ondřej Podrazký, Ph.D.; Marie Pospíšilová, Ph.D.

From: 2008-01-01

To: 2009-12-31

The project focused on the preparation methods of optical fibers modified by layers of nanoparticles of titanium oxide (anatase), which has the photocatalytic effect when they are excited at wavelengths above 300 nm. Such optical fibers allow the increase of the efficiency of decomposition by their extension.

The project solution was prepared by the original method for the continuous application of photocatalytic coatings on quartz fibers in the process of drawing. Were prepared fiber segments with length up to 10 m (see Fig. 1)

Fig. 1. Photo of a bundle of quartz optical fibers coated with nanoparticles of anatase (7 m)

Photocatalytic activity of the samples was characterized by measuring the kinetics of decomposition of methylene blue (MB). For these measurements, the original method was developed using fiber-optic sensor element U with the help of MB absorbance was measured at 665 nm. Examples of experimental results obtained from the degradation of MB in Fig. 2

Fig. 2. The time course of degradation of methylene blue on the initial concentration of c0 =10 μM measured for two types of photocatalytic coatings on fibers (THP - titanium tetraisopropoxide)

Reference:

1. V. Matějec et al. Fiber-optic U-shaped elements for investigation of photocatalytic activity of optical fibers coated with TiO2, Sensor Letters 2009, Vol. 7, pp. 900-904.