Novosibirsk scientists create photocatalysts for the oxidation of carcinogenic benzene

Scientists of the Institute of Catalysis SB RAS are developing photocatalytic systems for the oxidation of benzene, a carcinogenic aromatic hydrocarbon, which is isolated, including household plastics. In the future, new catalysts can be used in a new generation of air purifiers, the press service of the Institute told TASS on Tuesday.

"Scientists are actually creating next-generation photocatalysts. Titanium dioxide and mercury lamps are used in existing air purifiers on the market. The resulting composite, active under visible light, will allow using not mercury lamps, which are difficult to dispose of, but safe and energy-efficient LED sources," the report says.

The press service added that the advantages of the new catalysts being created are that they will work under visible light.

To neutralize benzene, it, like other organic air pollutants, is oxidized - destroyed and converted into carbon dioxide and water, but benzene leads to deactivation of the oxidizing catalyst. When a benzene molecule hits the surface of the catalyst, it falls apart into several "fragments" and begins to take up a lot of space. Because of this, its oxidation and the influx of the following molecules are hindered. Scientists are faced with the task of creating a system that will be active and stable in the fight against benzene. The research is carried out with the support of the Russian Science Foundation.

Experts use titanium dioxide as a basic component. "The most effective oxidizer at the moment is titanium dioxide. It is efficient and stable, but its disadvantage is that it absorbs only ultraviolet light for benzene oxidation. We need to create systems that will work under visible light. We use titanium dioxide doped with nitrogen due to the use of a nitrogen-containing precursor at the synthesis stage - ammonia, as well as bismuth tungstate. Nitrogen is embedded in the structure of titanium dioxide, and it becomes active under visible light," the press service quotes Mikhail Lyulyukin, senior researcher at the Department of Unconventional Catalytic Processes at the Institute of Catalysis SB RAS. Bismuth tungstate increases the stability of nitrogen-doped titanium dioxide - the activity of the catalyst does not decrease over time, but remains.

"Problematic" connection Benzene is a "problematic" compound.

It has a very low maximum permissible concentration - if there is a characteristic sweet smell, it means that its level is greatly exceeded. "Benzene often surrounds us. It is used as a solvent, contained in plastics and insulation materials. There are systems of trapping and cleaning at the production facilities, and safety precautions are observed. And it's hard to say how much benzene we inhale every day indoors," Mikhail Lyulyukin said.

Benzene is the simplest aromatic hydrocarbon, which has a high carcinogenicity. When it accumulates in the body, it leads to blood diseases such as anemia and leukemia, as well as bone marrow. With acute benzene intoxication, swelling of the brain and stagnation of blood in the lungs may occur.