Photocatalytic properties of TiO2 for the degradation of O3: Examined by environmental parameters

Abstract

This paper describes how environmentally relevant parameters affect titanium dioxide's photocatalytic properties (TiO2) to decompose ozone (O3). Thus, experiments have been carried out in a box chamber with TiO2 coated roofing membrane samples to determine the significance of light intensity, temperature, initial O3 concentration, and relative humidity. Furthermore, an outdoor experiment has been conducted where the roofing membrane was subjected to natural sunlight. The results show a significant photocatalytic effect of TiO2. The half-life of the O3 decay curve is 5.8 min in near-ambient UV-light exposure compared with 7.1 min in dark conditions. Experiments conducted at higher light intensity show a more extensive degradation of O3, where the value of the reactive uptake coefficient increases from 0.044 to 0.051. Also, the measurements carried out under natural sunlight show a photocatalytic effect where the uptake coefficient value is 0.046. A larger photocatalytic effect is detected for the experiments conducted at 283 K and 303 K temperatures compared with experiments under standard conditions. Experiments carried out with a very high initial concentration of O3 show that 28.1 μg of O3 is decomposed than ambient conditions, where 2.3 μg is destroyed. This demonstrates that light intensity, temperature, ozone concentration, and relative humidity significantly impact TiO2's degradation of O3.