Titania photocatalyst recycles CO2 into hydrocarbons

This is the claim of researchers at the Daegu Gyeongbuk Institute of Science and Technology (DGIST), who developed and tested the modified photocatalyst with colleagues in Korea, Japan, and the US.

It is said to have converted sunlight to fuel with an efficiency of 3.3 per cent over 30-minute periods. This 'photoconversion efficiency' is an important milestone, the researchers report in their study published in Energy and Environmental Science, as it means that large-scale use of this technology is becoming a more realistic prospect.

Photocatalysts are semiconducting materials that can use the energy from sunlight to catalyse a chemical reaction. Scientists are investigating their use to trap carbon dioxide from the atmosphere as a way of alleviating global warming.

According to DGIST, some photocatalysts are being tested for their ability to recycle carbon dioxide into hydrocarbon fuels like methane, the main component found in natural gas. They say that methane combustion releases less carbon dioxide into the atmosphere compared to other fossil fuels, making it an attractive alternative. Scientists have, however, had difficulties manufacturing photocatalysts that produce a large enough yield of hydrocarbon products for their use to be practical.