Pollutants in the air can be taken in by a new material

Professor Michael Zaworotko, Bernal Chair of Crystal Engineering and Science Foundation of Ireland Research Professor at University of Limerick’s Bernal Institute. Below, Dr Xiang-Jing Kong from the Department of Chemical Sciences at UL and the material that has been created – named BUT-55. Credit: University of Limerick

Researchers at the University of Limerick have made a new material that can take dangerous chemicals out of the air.

Researchers say that the material can pick up small amounts of benzene, a toxic pollutant, from the air and does so with less energy than materials that are already on the market.

Researchers think that the porous material that looks like a sponge could change the way people look for clean air and make a big difference in the fight against climate change.

Professor Michael Zaworotko, who holds the Bernal Chair of Crystal Engineering and is a Science Foundation of Ireland Research Professor at the Bernal Institute at the University of Limerick, and his team made the new material. The results were published in Nature Materials.

Volatile organic compounds (VOCs), which include benzene, are a type of toxic pollution that causes serious problems for the environment and for people’s health. Until now, it has been hard to come up with ways to remove benzene from the air when it is present in very small amounts and to do so in a way that uses little energy.

Professor Zaworotko said, “A family of porous materials like sponge has been made to remove benzene vapour from polluted air and produce a stream of clean air for a long time.”

“These materials could easily be made new with a little heat, which makes them good candidates for cleaning the air and fixing the environment.

“Our materials are much more sensitive and take less time to work with than other materials.”

Professor Zaworotko and Dr. Xiang-Jing Kong from the Department of Chemical Sciences at UL, along with researchers from top universities in China, made the new porous material. It has such a strong affinity for benzene that it can capture the toxic chemical even when it is only present at a level of 1 part in 100,000.

Researchers say that the holes in this material, which looks like Swiss cheese, are what make the benzene molecules want to stick to it.

Because the process of capturing is based on physical rather than chemical bonds, the energy needed to capture and release is much less than with older materials.

“It’s hard to break up gas mixtures. This is especially true for carbon dioxide and water, which are two of the smaller parts of air. “The way our new material works shows that benzene is no longer hard to break up,” Professor Zaworotko said.

Professor Zaworotko’s lab has made some of the best materials for capturing carbon and collecting water. The water harvesting material is already being used in dehumidification systems because it is so good at taking in and releasing water from the air.

Dr. Xiang-Jing Kong said, “Based on smart design, our materials are good at solving problems that are both technical and important to society, like removing trace amounts of benzene from the air. This is hard to do with most materials, which shows how great porous materials are.

Overall, these results suggest that a new generation of custom porous materials like the ones made at UL can be used to remove toxic chemicals from the air in a more general way.

“Traditional methods, which always require a lot of energy, make it hard to separate aromatic isomers from their mixtures,” Dr. Xiang-Jing Kong said.

“This research made it possible to design porous materials that can separate these chemicals and other trace pollutants from the air in a way that uses little energy.”

Further information: Tao He et al, Trace removal of benzene vapour using double-walled metal–dipyrazolate frameworks, Nature Materials (2022). DOI: 10.1038/s41563-022-01237-x

Journal information: Nature Materials

Source: University of Limerick