Comparison of the photoactivity of TiO2 coatings using a flat panel reactor and FTIR to monitor the CO2 evolution rate

Abstract

Abstract A system designed to continuously monitor the gas phase for the UV irradiation of flat panels of organic coatings has been modified to compare the photocatalytic degradation of organic pollutants using TiO2 functional coatings. TiO2 was formulated into pastes and was coated onto various stainless steel and glass fibre meshes. The photoactivity was determined by monitoring the photodegradation of acetone and following the rate of CO2 evolution using FTIR spectroscopy. The kinetics were compared to the photoinduced degradation of indigo carmine, followed by UV–vis spectroscopy to determine whether the CO2 evolution method is a viable, rapid alternative to photodegradation monitoring. A correlation was established between the two methods by determining the rate constants of the decolourisation of indigo carmine and CO2 evolution, demonstrating that such a method can be used as a rapid assessment of the photoactivity of photocatalytic coatings.