Photocatalytic degradation of selected herbicides in aqueous suspensions of doped titania under visible light irradiation

Structural, optical and photodegradation properties of pure and Fe-doped titania nanoparticles probed using simulated Solar light

“…As already stated, it was found that the incorporation of Fe ions into the titania matrix forms sub-band states in the band gap of TiO 2 [5,6]. The reflection spectra of the doped samples are characterized by a shoulder between 450 and 500 nm and the intensity increases with annealing.…”

“…Some experimental results have also shown that the incorporation of Fe-ions in TiO 2 crystal structure can do both: they narrow the band gap of TiO 2 , and reduce the electron-hole recombination rate and thereby increase the photocatalytic efficiency of TiO 2 using visible light [5 -8]. Numerous investigations have shown that the photocatalytic activity of Fe-doped TiO 2 is strongly dependent on the dopant concentration; higher contents of Fe 3+ usually result in an increase in the recombination rate of photogenerated electrons and holes and thus a decrease in the photocatalytic activity [6][7][8][9][10][11][12][13][14]. If the iron concentration exceeds the optimal level, the Fe 3+ ions steadily become the recombination centres of photogenerated electrons and holes.…”

Elongated titania nanostructures as efficient photocatalysts for degradation of selected herbicides

“…At pH ∼8.0 electrical forces are generated, i.e., the repulsion between the negatively charged surface of the catalyst and COO − . However, higher efficiency in the case of mecoprop degradation is probably due to the electron-donor or electron-withdrawing character of the different substituents in the herbicide aromatic/pyridine ring, which can activate/deactivate the ring with respect to the electrophilic attack of the • OH radical [33]. This may be explained in terms of the effect of CH 3 group as substituent.…”

Comparative Assessment of the Photocatalytic Efficiency of TiO2 Wackherr in the Removal of Clopyralid from Various Types of Water

“…Because of their frequent use, chemical stability and resistance to biodegradation, they are encountered in waste waters, and, due to their hazardous effects on ecosystems and human health, their removal is imperative (Stapleton et al, 2006). With this in mind, we have recently paid significant attention to the study of the model compounds (Abramović et al, 2003;Abramović et al, 2004aAbramović et al, , 2004b and pyridine containing pesticides (Abramović et al, 2007;Šojić et al, 2009;Guzsvány et al, 2010;Šojić et al, 2010a, 2010bBanić et al, 2011).…”

“…Due to these properties, CLP has recently been reported to occur in drinking water at concentrations above the Permitted Concentration Value of 0.1 μg L -1 for an individual pesticide (EU directive 98/83/EC). Although the occurrence of CLP in surface, ground and drinking waters has been widely reported, there are only a few studies concerning with its photocatalytic removal from water (Šojić et al, 2009;Šojić et al, 2010a, 2010bTizaoui et al, 2011). These studies showed that the degradation of this herbicide takes place most effectively in the presence of Degussa P25 as photocatalyst.…”