UQ turns carbon dioxide into sustainable power

Researchers at the University of Queensland have built a generator that absorbs carbon dioxide to make electricity. Dr Zhuyuan Wang from UQ’s Dow Centre for Sustainable Engineering Innovation said the small, proof-of-concept nanogenerator is carbon negative because it consumes the greenhouse gas.

“This nanogenerator is made of two components: a polyamine gel that is already used by industry to absorb CO₂ and a skeleton of boron nitrate a few atoms thick that generates positive and negative ions,” Wang said. “We’ve worked out how to make the positive ions much larger than the negative ions and because the different sizes move at different speeds, they generate a diffusion current that can be amplified into electricity to power light bulbs or any electronic device.

“In nature and in the human body, ion transportation is the most efficient energy conversion — more efficient than electron transportation, which is used in the power network.”

The two components were embedded in a hydrogel that is 90% water, cut into 4 cm discs and small rectangles and then tested in a sealed box pumped full of CO₂.

“When we saw electrical signals coming out, I was very excited but worried I’d made a mistake,” Wang said. “I double-checked everything, and it was working correctly so I started dreaming about changing the world using this technology.

“This technology goes further than being carbon neutral — it consumes CO₂ as it generates energy. At present we can harvest around 1% of the total energy carried intrinsically by CO₂ gas but like other technologies, we will now work on improving efficiency and reducing cost.”

Director of the Dow Centre Professor Xiwang Zhang said following the success of the laboratory tests, there are two potential applications for the nanogenerator in the future.

“We could make a slightly bigger portable device for generating electricity to power a mobile phone or a laptop computer using CO₂ from the atmosphere,” he said. “A second application on a much larger scale would integrate this technology with an industrial CO₂ capture process to harvest electricity.”

The development of the nanogenerator will continue through GETCO2, the ARC Centre of Excellence for Green Electrochemical Transformation of Carbon Dioxide which is led by UQ’s School of Chemical Engineering with Zhang as Director.

“We want to realise the value in a problematic greenhouse gas and to change the perception of CO₂,” Zhang said. “Until now CO₂ has been seen as a problem to be solved but it can be a resource for the future.”

The research has been published in Nature Communications.

Image caption: L-R, Professor Xiwang Zhang and Dr Zhuyuan Wan, University of Queensland.