UCR’s Mihri Ozkan. Photo: UCR.
UCR’s Mihri Ozkan. Photo: UCR.

Some of the thinnest materials known to mankind may provide solutions to scientists in their quest to curb the effects of global warming.

Known as MXene and MBene compounds, these substances are only a few atoms thick, making them two-dimensional (2D). Because of their large surface areas, these materials have the potential to absorb molecules of carbon dioxide from the atmosphere, helping to reduce the harmful effects of climate change by safely sequestering this potent greenhouse gas.

In a paper in Chem, Mihri Ozkan and her colleagues at the University of California, Riverside (UCR) explain the potential of MXenes and MBenes for carbon-capture technologies.

“In this review, we conducted an exhaustive analysis and proposed strategies for the widespread implementation of these materials in large-scale applications,” said Ozkan, a climate action professor in UCR’s Electrical and Computer Engineering Department at the Bourns College of Engineering. “Their unique properties make them excellent candidates for capturing carbon dioxide.”

According to Ozkan, these 2D materials can be engineered to selectively capture carbon dioxide, via a process called interlayer distance engineering. What is more, the materials are mechanically stable and maintain their structural integrity even after multiple cycles of carbon capture and release.

As human-caused carbon dioxide emissions continue to increase, developing carbon-capture technologies has become a top priority. It is projected that the planet's temperature could rise by 1.5°C above pre-industrial levels within the next decade, leading to more frequent severe weather events, worsening drought, crop failures, increased levels of human migration and political instability. These negative impacts highlight the urgent need for action to curb carbon emissions and mitigate the effects of climate change.

Scientists at Drexel University discovered MXenes and MBenes in the early 2010s. MXene is an inorganic compound made up of atomically thin layers of transition metal carbides and nitrides or carbonitrides, while MBenes are dimensional transition metal borides made from boron. Both these materials are produced through chemical etching techniques and have crystalline lattices with repeating orthorhombic and hexagonal structures.

Ozkan explained that these materials can be used in conjunction with existing carbon-capture technologies, such as those developed by the Swiss company Climework AS. These systems extract carbon dioxide directly from the atmosphere and sequester it for safe and long-term storage.

But before these 2D materials can be used in carbon-capture devices, several technical issues need to be resolved. First and foremost, scientists must address the bottlenecks associated with synthesis-related challenges in large-volume production. Other obstacles to large-scale manufacturing include non-uniform mixing, temperature gradients and problems with heat transfer, among others.

Still, these hurdles can be overcome. A top-down approach is ideal for large-scale MXene synthesis by scaling up wet-etching methods or developing new ones, says Ozkan.

This story is adapted from material from the University of California, Riverside, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.