Effect of irradiation intensity on the rate of photocatalysis of TiO2 coatings obtained by detonation spraying

Abstract

AbstractThe influence of UV irradiation intensity on the rate constant of photocatalytic reaction of TiO2 coatings applied by detonation spraying on the hot‐rolled carbon steel and glass‐cloth‐base laminate (plastic) is studied. The effect of substrate material on the studied phenomenon is pronounced. The kinetic curves at different UV irradiation intensities and the rate constants of the photocatalytic reaction are obtained for different values of energy flux density varied from 3.0 to 8.0 mW/m2. The photocatalytic rate constant of coatings placed on plastic increases with an increase in the energy flux density from.038 to.055 1/h. Samples applied at a spray distance of 50 mm are characterized by a higher the photocatalytic rate constant than those applied at a distance of 40 mm. The value of photocatalytic rate constant does not change starting from a certain flow value for such samples and reaches the saturation value of about.054 1/h. Saturation is achieved quite quickly already at a density flux of about 5.5 mW/m2. Two new phenomenological models based on differential equation, the analytical solutions to which sufficiently describe experimental dependence of the photocatalytic rate constant on the energy flux density, are proposed.