Novel Material Captures Carbon from Thin Air

For years, Berkeley chemist Omar Yaghi and his team have been doing amazing things with novel classes of materials Yaghi invented called metal-organic frameworks (MOFs) and covalent organic frameworks (COFs). Most notably, they’ve pulled drinking water from desert air using MOFs. The ultra-porous structures have also shown promise in applications as varied as energy storage in batteries and drug delivery in bodies. 

And now, COFs are proving to be an exceptionally effective material for stripping carbon from the air—something humanity needs to do at scale if we’re to avoid the worst consequences of climate change. 

Professor Yaghi’s lab has developed a new, bright-yellow substance called COF-999 that has the ability to pull CO₂ not just from concentrated sources like flue gases or exhaust pipes but from ambient air. 

“We took a powder of this material, put it in a tube, and we passed Berkeley air—just outdoor air—into the material to see how it would perform, and it was beautiful. It cleaned the air entirely of CO₂. Everything,” Yaghi told Berkeley News. “There’s nothing like it out there in terms of performance,” he added. “It breaks new ground in our efforts to address the climate problem.”

Indeed, Berkeley graduate student Zihui Zhou from Yaghi’s lab said that just 200 grams of the COF material can take up as much CO₂ in a year as a mature tree—about 20 kilograms’ worth. Better still, unlike with other synthetic CO₂-capturing materials, COF-999 releases the carbon at low temperatures and can go through 100 cycles of capture and release without degrading. 

Yaghi tells Berkeley News he’s further excited about the possibility of using machine learning to speed the design of superior MOFs and COFs in his role as co-director and chief scientist of Berkeley’s Bakar Institute of Digital Materials for the Planet. The work could not be more crucial. As Yaghi told the Los Angeles Times, “You have to take CO₂ from the air—there’s no way around it. Even if we stop emitting CO₂, we still need to take it out of the air. We don’t have any other options.”