The University of Queensland discovery, outlined in the journal Nature Communications, uses ions of different sizes to create electricity while removing carbon dioxide from the air.
Scientists behind the development say it might help redeem the gas's bad reputation and the technology could be expanded in future to charge devices such as smartphones and laptops in a way that would benefit the environment.
UQ research officer Dr Zhuyuan Wang, from the Dow Centre for Sustainable Engineering Innovation, told AAP he had been working on the project for three years but was surprised to see the nanogenerator consuming carbon dioxide during tests.
"When we saw electrical signals coming out, I was very excited but worried I'd made a mistake," he said.
"I double-checked everything and it was working correctly so I started dreaming about changing the world using this technology."
The generator creates positive and negative ions of different sizes to create electricity in a process called ion transport.
To test whether it consumed greenhouse gases, Dr Wang said the team placed the equipment "in a sealed box and we pumped the gas" inside.
Generators used in the research project were small - one is just 4cm wide and another is 6cm long - but Professor Xiwang Zhang said the equipment could be enlarged and made more powerful for future, practical applications.
"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," he said.
"I think this hasn't been done before and this shows great potential."
Prof Zhang said researchers could also seek to expand the technology for use on an industrial scale, which could harvest more carbon dioxide and potentially improve the reputation of the maligned gas.
"Until now, CO2 has been seen as a problem to be solved but it can be a resource for the future," he said.
"We want to realise the value in a problematic greenhouse gas to change the perception."
Prof Zhang said researchers would continue to refine the technology through the Australian Research Council's Centre of Excellence for Green Electrochemical Transformation of Carbon Dioxide.
The UQ project is not the first to investigate how to use carbon dioxide to generate a source of energy, however, with researchers at MIT and Harvard University in 2023 announcing they had developed a process to convert the gas into a fuel called formate that could be used in a similar way to hydrogen.
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