Aqueous solutions of the dye indigo carmine were decolourised following ultraviolet (UV) irradiation in the form of thin liquid films in the presence of the semi-conductor photocataIyst, titanium dioxide, TiO2. These films, which were unsupported and totally enclosed, are com monly referred to as liquid "bells" and were generated using a nozzle of special design, Decolourisation rates were increased as the concentration of TiO2 was increased from 0.74 to 11.8 g/l. Addition of hydrogen peroxide, H2O2, in concentrations ranging from 1.07 to 8.53 g/l at a fixed TiO2 concentration of 1.47 g/l also resulted in increased rates of decolourisation. The rate of disappearance of the indigo carmine was assumed to follow first order kinetics whereas the influence of the two other species, TiO2 and H2O2, was accounted for by a power law model. The exponents for this model, obtained from an analysis of the experimental data, were 0.8 and 0.2 for, respectively TiO2 and H2O2.