where [[lambda].sub.mv] is the wavelength of
visible radiation. This is about 1013 times less than the diameter of a carbon atom.
Ti[(OH).sub.4] presented a band gap energy value of 2.15 eV, with an onset of absorption from 576 nm, indicating that this catalyst is sensitive to visible light, which represents a possible photoactivity under
visible radiation.
Furthermore, band gap value indicates that catalyst can be active in the visible region of the electromagnetic spectrum; if semiconductor absorbs
visible radiation it could be useful for degrading pollutant for using direct solar radiation [21, 22].
Visible radiation (400-750nm) causes problems with glare, an issue experienced by most people at times and is caused by bright sunlight, VDU screens and fluorescent lighting.
They absorb almost all of its
visible radiation and re-emit it in the infrared.