Odor removal mechanism of photocatalytic reaction in photocatalyst filter mesh

Take common aldehydes and alcohols as examples, their reaction mechanism in photocatalyst filter mesh is as follows:
Adsorption stage: Odor molecules are first adsorbed on the surface of photocatalyst to form an adsorbed state. This process is an important factor affecting the efficiency of the reaction. The more adsorbed substances, the more effective the reaction.
Oxidation reaction:
Aldehydes (such as acetaldehyde) can react with active oxygen species (such as OH) to generate acids or other intermediates. Further oxidation reactions convert acids into carbon dioxide and water, ultimately releasing energy.
Reaction of alcohols:
Alcohols (such as ethanol) undergo dehydrogenation reactions under the action of photocatalysts to generate aldehydes, which are further degraded through the above-mentioned aldehyde reaction pathways.
Complex reaction network:
In practical applications, odor molecules are often composed of multiple compounds, and the reaction process is relatively complex. Photocatalysts can effectively degrade multiple odor sources through different oxidation pathways, forming a complex reaction network.
The efficiency of photocatalytic reactions is affected by a variety of factors, including:
Light intensity: The intensity of the light source directly affects the degree of electron excitation, which in turn affects the reaction rate. Higher light intensity generally improves reaction efficiency.
Photocatalyst properties: The specific surface area, crystal phase, and number of active sites of the photocatalyst all have an important impact on its catalytic performance. Nanoscale photocatalysts generally have a larger specific surface area and can more effectively contact odor molecules.
Temperature and humidity: Increased temperature generally helps to increase the reaction rate, but too high a temperature may cause the photocatalyst to inactivate. When the humidity is moderate, moisture can promote the generation of active oxygen species, but too high a humidity may inhibit the reaction.
Odor component concentration: Different concentrations of odor molecules have different effects on the reaction rate. Too high a concentration may cause the saturation of the photocatalyst, thereby reducing the reaction efficiency.