Porous material captures harmful pollutants from the air

A material capable of capturing toxic chemicals from the air has been developed by researchers at the University of Limerick in Ireland.

The material is able to capture trace amounts of benzene, a toxic pollutant, from the air while using less energy than existing materials, the researchers said.

Benzene is an air toxic typically emitted from gas stations, motor vehicle exhaust and fuel evaporation, coal and oil combustion, and various other sources.

Volatile organic compounds (VOCs), including benzene, are a class of toxic pollutants that cause serious environmental and health problems. Developing technologies to remove benzene from the air at minute concentrations and doing so with a small energy footprint are two challenges that have not been overcome so far.

Hardware close-up

Image credit: UL/Bernal

“A family of porous materials – like sponge – have been developed to capture benzene vapor from polluted air and produce clean airflow over a long working period,” said research professor Mike Zaworotko.

“These materials could be regenerated easily under gentle heating, making them candidates for air purification and environmental remediation.

“Our materials can do much better in terms of sensitivity and working time than traditional materials.”

The porous new material, which resembles Swiss cheese, has such an affinity for benzene that it captures the toxic chemical even when it is present at just 1 part in 100,000.

Because the capture process is based on physical rather than chemical bonding, the energy footprint of capture and release is much lower than that of previous generations of materials, the researchers said.

“Decomposing gas mixtures is hard to do. This is especially true for minor components that include air, including carbon dioxide and water. The properties of our new material show that the decomposition is no longer difficult for benzene,” explained Zaworotko.

Another project researcher, Dr. Xiang-Jing Kong, explained: “Based on intelligent design, our materials succeed in meeting both technical and social challenges, such as removing traces of benzene from the air. . It is difficult for conventional materials, and thus emphasizes the charm of porous materials.

The results suggest that a new generation of tailored porous materials could be developed to enable a general approach to capturing toxic chemicals in the air.

“Aromatic isomers are difficult to separate in their mixtures with traditional methods, which are always energy-intensive,” Kong added.

“This research has opened up possibilities for designing porous materials for efficient separation of these chemicals with low energy input as well as removal of other trace pollutants from the air.”

In March, the World Health Organization found that no country had managed to meet its annual air quality guidelines.

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