Find out toxic absorbers from the air

A new material that promises to remove some harmful substances from the air has been created by a team of scientists from the University of Limerick (UL) in Ireland. According to the team of researchers, the substance uses much less energy than current materials and can record trace levels of harmful pollutants such as benzene from the air.

The team of researchers believe that the sponge-like material - dubbed BUT-55 - could revolutionize the purification of toxic air and make a significant contribution to the fight against climate change globally. . Professor Michael Zaworotko - Chairman of the Crystal Science and Engineering Foundation of Ireland and a researcher at the Bernal Institute of the University of Limerick - and colleagues developed this new material. The discovery was reported in the prestigious journal Nature Materials in 2022.

Professor Michael Zaworotko.

Volatile organic compounds (VOCs) - including benzene - are a class of toxic pollutants that cause serious environmental and human health problems. Developing the technology to remove benzene from the air at trace concentrations and carrying out that mission with a low-energy trace are both challenges that have been insurmountable so far.

Professor Zaworotko explains: 'A family of porous materials - such as sponges - have been developed to capture benzene vapor from polluted air and create a stream of clean air over a long period of time. These materials can be regenerated easily under mild temperatures, 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 actual material is full of holes and closely resembles Swiss cheese. The holes allow the attraction of benzene molecules - a toxic pollutant.

Professor Zaworotko and Dr. Xiang-Jing Kong from the Department of Chemical Sciences at UL, together with a group of colleagues from several leading universities in China, have developed new porous materials with strong affinity for benzene to level it captures toxic chemicals even when present in only 1 part in 100,000.

According to the team of researchers, the material is similar to Swiss cheese because it has many holes, and it is these holes that are responsible for attracting the toxic molecule benzene. In terms of energy, since acquisition is based on physical rather than chemical binding, the energy footprint of acquisition and release is much lower than in previous generations of materials.

Prof Zaworotko reports: 'The task of breaking up the gas mixture is difficult to do effectively. This is especially true for secondary components that include air, which includes carbon dioxide and water. The properties of our new material suggest that benzene degradation is no longer a problem."

The BUT-55 was created at the Bernal Institute, University of Limerick.

Some earlier work from Professor Zaworotko's lab has produced leading materials for carbon capture and water harvesting. Water harvesting materials have such favorable properties for capturing and releasing water from the atmosphere that are already used in desiccant systems.

Dr Xiang-Jing Kong explains: 'Based on intelligent design, our materials well solve many technical and social challenges, such as removing traces of benzene from the air. This is difficult for conventional materials, and thus highlights the charm of porous materials'.

Collectively, these results show that a new generation of unique porous materials of the kind invented at UL holds promise for enabling a common approach to capturing hazardous chemicals from the air.

Dr Xiang-Jing Kong explains: 'The aromatic isomers are difficult to separate in their mixtures by traditional methods, which are always energy intensive. This research opens up the possibility of designing porous materials to efficiently separate these chemicals with low energy input as well as remove many other trace pollutants from the air.