Photocatalytic reduction of nitrobenzene over titanium dioxide:: by-product identification and possible pathways

The photocatalytic reduction of nitrobenzene (ethanol + TiO2 + UV-light) in non-aqueous suspension yielded aniline and acetaldehyde as main products. However, various by-products as intermediates of nitrobenzene photoreduction (i.e. nitrosobenzene and hydroxyaniline) and others (i.e. indoles and quinolines) were also detected. These last results were explained in terms of reactions between aniline and oxidation products of ethanol.