Photocatalytic reduction of p-chloronitrobenzene on illuminated nano-titanium dioxide particles

The photocatalytic reduction of p-chloronitrobenzene in titanium dioxide slurries in the absence of oxygen and in the presence of the sacrificial electron donors under UV light irradiation was investigated in the present study. TiO2 used were A101, P25, and R201. The sacrificial electron donors consisted of isopropanol, methanol, ethanol, formic acid, etc. The results of photocatalytic reduction reaction were monitored with HPLC method by identifying reduction products. The effects of reduction time, properties and loading of TiO2, concentration of substrate, types and ratio of photogenerated hole scavenger on reductive rate and yield of p-chloroaniline were evaluated. p-Chloroaniline yield could reach high up to 99.20% in 12 h for P25 used, while for A101 it was 68.22% and for R201 only 15.06%. In general, P25 was the best one of all the catalysts used. The mixture of i-propanol and formic acid (v:v = 90:10) was selected as reductive medium because of less by-product and higher p-chloroaniline yield.