Nanogenerator consumes CO2 to generate electricity

Researchers at the University of Queensland have developed a proof-of-concept nanogenerator that generates electricity when filled with carbon dioxide (CO2).

The UQ-developed technology absorbs carbon dioxide and generates electricity
The UQ-developed technology absorbs carbon dioxide and generates electricity - University of Queensland

Dr Zhuyuan Wang from UQ’s Dow Centre for Sustainable Engineering Innovation said the small nanogenerator is carbon negative as it is a consumer of 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 a few atoms thick of boron nitrate that generates positive and negative ions,” Dr Wang said in a statement.

“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 which 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, cut into 4cm discs and small rectangles and tested in a box filled with CO2.

“When we saw electrical signals coming out, I was very excited but worried I’d made a mistake,” said Dr Wang.

“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 one per cent of the total energy carried intrinsically by gas CO2, but like other technologies we will now work on improving efficiency and reducing cost.”

Dow Centre director Professor Xiwang Zhang believes there are two potential applications for the nanogenerator.

“We could make a slightly bigger device that is portable to generate electricity to power a mobile phone or a laptop computer using CO2 from the atmosphere,” said Professor Zhang. “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.

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

The team’s findings are detailed in Nature Communications.