Efficiency of iron(III)oxide in photocatalytic degradation of the fungicide metalaxyl

On the basis of quantitative 1 H NMR results we concluded that the photocatalytic degradation of the fungicide metalaxyl in the presence of Fe2O3 as photocatalyst, in the initial period, follows the first-order kinetics with reaction rate 4.4 times slower than with the TiO2 as photocatalyst.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200

Synthesis and chemical behaviour of 17a-butyl-3b,17b-dihydroxy-16-oximino-5-androstene (NOTE)

Starting from 3b-hydroxy-16-oximino-5-androsten-17-one (1), the recently synthesized 16-oximino-17b-hydroxy-17a-butyl derivative 2 gave by the Beckmann fragmentation reaction with titanium(III) chloride or p-toluenesulphonyl chloride the corresponding D-seco derivative 3. However, using acetic anhydride, in addition to the 3b-acetoxy D-seco derivative 4, the 17-aza D-homo derivative 5 was obtained. The structure of compound was proposed on the basis of NMR-spectroscopy

Photocatalytic activity of synthesized nanosized TiO2 towards the degradation of herbicide mecoprop

The kinetics and possible mechanism of the photocatalytic degradation of herbicide mecoprop, in UV illuminated aqueous colloids of synthesized nanosized TiO2 were investigated. The rate of degradation was studied by H-1 NMR, UV spectrometry, as well as by potentiometric titrimetric determination of generated chloride. The catalyst dosage and effects of other kinetic factors on the photocatalytic degradation, such as initial substrate concentration, temperature and type of TiO2 were investigated as well. The degradation rates were found to be strongly influenced by the above parameters. It was found that photocatalytic efficiency is lower and that a smaller number of observed organic intermediates (only 4-chloro-2-methylphenol and acetic acid) was detected than those observed in the presence of TiO2 (Degussa P-25). Kinetics of the degradation were also monitored for direct photolysis, as well as for solar degradation in the presence and in the absence of TiO2. (C) 2004 Elsevier B.V. All rights reserved