Photochemical reactions of 2,4-dichloroaniline and 4-nitroanisole in aqueous suspension of titanium dioxide

The photochemical reactions of two selected organic systems, such as 2,4-dichloroaniline (1) and 4-nitroanisole (2) has been investigated in aqueous suspensions of titanium dioxide in the presence of atmospheric oxygen under a variety of conditions. The degradation was investigated by monitoring the change in substrate concentration employing UV-spectroscopic analysis technique as a function of irradiation time. Both the compounds were found to degrade in the presence of TiO₂. The degradation of these compounds were studied under different conditions such as different types of TiO₂, reaction pH, catalyst concentration, substrate concentration and in the presence of electron acceptors such as hydrogen peroxide, ammonium persulphate and potassium bromate besides atmospheric oxygen. The degradation rates were found to be strongly influenced by all the above parameters. The photocatalyst Degussa P25 was found to be more efficient for the degradation of model pollutants under investigation.