Groundbreaking research by Abu Dhabi scientists on a carbon material called graphene could lead to new ways of removing carbon dioxide from the atmosphere.
Removing CO2 rather than simply reducing emissions, is seen by many as essential given that the world is failing to meet climate goals aimed at limiting the effects of global warming.
The properties of graphene, a material extracted from graphite, could provide a breakthrough as research has uncovered a technique that changes it from being a conductor of electricity to an insulator, which opens up new uses.
The technology could potentially be applied to remove CO2 from the atmosphere and, without using expensive catalysts, turn it into something useful.
Published in the Nature scientific journal, the work is the result of a tie-up between Abu Dhabi's Khalifa University and the University of Manchester in Britain, along with other institutions in Belgium, Brazil and the UK.
The author of the new study, Dr Marcelo Lozada-Hidalgo, of the University of Manchester’s Department of Physics and Astronomy, said that because graphene was thin, strong electrical forces could be concentrated within it, allowing new phenomena to be observed.
“The idea is that you would use electric fields to drive these processes more selectively, ideally more efficiently and [in a] greener, cheaper [way]. It could have big implications,” Dr Lozada-Hidalgo said.
“Of course, this is only fundamental research. How you scale it up to realise that impact is yet another huge challenge.”
Michael Evans, chief executive of Cambridge Carbon Capture, a British company that develops ways to remove CO2 from the atmosphere, said that although his firm did not work with graphene, the material potentially could be used for CO2 removal.
“Graphene is an active surface that things can attach to and be detached from,” he said, adding that it may have applications as an alternative to what are known as metal organic frameworks, which are polymers made from metals and organic molecules that have been investigated for their CO2-removal properties.
“There’s a lot of research on metal-organic frameworks and graphene would, I imagine, be an alternative to that,” he said.
Mr Evans, who was not connected with the recent research, said that several groups were looking at this type of technology, although a challenge was that they often required large amounts of energy.
A fruitful partnership
The new study results from a 2022 agreement between Khalifa University and the University of Manchester to work on graphene research, collaborating in fields such as water filtration and desalination, energy storage and construction.
Khalifa University inaugurated the Research and Innovation Centre for Graphene and 2D Materials.
Dr Marcelo described the collaboration with Khalifa University as “excellent”, adding that it came about thanks to the UAE having “a very ambitious set of goals in energy and computing”.
“They have selected a few areas where they want to excel and they want to collaborate with some of the leaders in the world, and Manchester is a leading centre in 2D materials and that is why this collaboration started,” he said.
Graphene has sparked interest since it was first synthesised two decades ago, with the material having remarkable properties, such as weighing a sixth as much as steel yet being 200 times stronger.
Two of Dr Lozada-Hidalgo’s colleagues in the University of Manchester’s Department of Physics and Astronomy, Prof Sir Andre Geim and Prof Sir Kostya Novoselov, were awarded the Nobel Prize in Physics in 2010 for their work on graphene.
'Building block' to progress
In the study, researchers sandwiched the graphene between two non-water electrolytes and set up electrical “gates” on either side between which electrons, which are negatively charged particles, could flow through the graphene.
A second mechanism was also created in which protons (positively charged particles) were able to “soak up” the electrons, turning the graphene into an electrical insulator.
“What we discovered was that in 2D crystals you have access to two parameters – the charge density (how much charge you have in your 2D crystal) and you can independently control the electrical field in the system,” Dr Lozada-Hidalgo said.
“These two parameters are usually coupled and you have no control over them. We found we can decouple these parameters in a 2D crystal and, crucially, we demonstrated that this is useful.”
This has applications in computing because it means a single circuit could carry out two functions simultaneously, but also has relevance beyond this.
“This is relevant beyond computing because it is one of the simplest electrochemical processes that can take place in a 2D crystal,” Dr Lozada-Hidalgo said.
“This could be a building block in more complex and difficult-to-control processes for energy applications, such as CO2 reduction.”
Other authors of the study include Prof Lourdes Vega and Dr Daniel Bahamon Garcia, both of Khalifa University’s Research and Innovation Centre on CO2 and Hydrogen and the Chemical Engineering Department.
'A milestone achievement'
Prof Vega said that the research represented a breakthrough.
“Such control between both the proton transport and the two conductive states (insulator and conductor) are so robust and reproducible that it can be exploited to build a device that performs both memory and logic functions,” she said.
“[This is] a milestone achievement because it combines the functionalities of two devices into one and eliminates the need for other circuits to link them.”
Khalifa University and the University of Manchester are set to continue working together on graphene and other 2D materials.
“There’s a huge area of opportunity,” Dr Lozada-Hidalgo said. “You have new processes and new 2D crystals so there’s a lot of work to do. We definitely see ourselves working with Khalifa in these new projects and we are partnered with them so the collaboration will keep going.”
