INFLUENCE OF HUMIDITY AND ENVIRONMENTAL CONDITIONS ON THE EFFICIENCY OF PHOTOCATALYTIC AIR PURIFICATION. A BRIEF ANALYSIS

This study analyzes the influence of environmental parameters on the efficiency of photocatalytic processes for air purification. Modern photocatalytic air purification systems utilize light-activated semiconductor materials to generate reactive oxygen species capable of oxidizing pollutants to less toxic products. Experimental data indicate significant progress in the development of photocatalysts based on oxide and heterostructured materials. However, the high activity of photocatalytic materials demonstrated in laboratory conditions is not always reproducible under real-world environmental conditions. The study focused on the influence relative humidity, solar radiation intensity, ambient temperature, and mass transfer conditions on the kinetics of photocatalytic reactions and the availability of active surface sites. It was found that the effect of humidity is nonlinear and is determined by the balance between the formation of hydroxyl radicals and the competing adsorption of water molecules and target pollutants. The efficiency of photocatalytic processes under real-world conditions is determined not only by external environmental parameters but also by the structural design of the systems themselves. Integrated photocatalytic structures, such as fibrous membranes and composite materials, offer the most promise. These structures provide simultaneous filtration, adsorption, and catalytic oxidation of pollutants, as well as improved mass transfer to active sites. This architecture significantly improves the stability and reproducibility of photocatalytic activity under varying environmental conditions. A further evaluation of practical efficiency was conducted, taking into account the formation of reaction intermediates and their potential impact on human health. It was shown that the use of photocatalytic oxidation without preor concomitant filtration can lead to the formation of undesirable byproducts, whereas combined systems provide more thorough air purification and reduce the negative impact on cardiorespiratory parameters. Overall, the obtained results indicate the need to move from a material-based approach to a systems-based design of photocatalytic technologies, taking into account their real-world operating conditions.

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