Researchers harness sunlight to rapidly purify wastewater

Posted 17 March 2017

sunlightWastewater can be rapidly and cheaply purified using sunlight, an Australian-led research team has discovered.

Many leading water purification products need ultraviolet light to work, but this new method uses modified titanium dioxide as a photocatalyst. 

Research group leader Australian National University's Professor Yun Liu said the team's invention was 15 times more efficient than leading commercialised products.

“With innovative chemistry design, we can use our photocatalyst to purify water with natural sunlight instead of UV light and dramatically reduce costs for operators,” said Liu, who works in the ANU Research School of Chemistry.

“Our photocatalyst can completely decompose organic pollutants in wastewater in 20 minutes, compared with the leading commercialised products which take one hour to decompose only 26% of the same pollutants.”

In addition to treating water for human consumption, the technology could be applied for making self-cleaning building materials including glass, and splitting water to make hydrogen fuel.

Photocatalysts can also be used to speed up chemical reactions used in industrial processes in automotive, construction, environmental, medical and other sectors.

As outlined in their recent paper, the team added nitrogen and niobium ions in pairs into the titanium dioxide to improve its performance as a photocatalyst.

“It's an important breakthrough for science and industry,” Liu said.

“With four years of work done in this area, we now understand the science and can rationally design catalysts.”

The research was completed in collaboration with the Chinese Academy of Sciences, the University of New South Wales, Western Sydney University and the Australian Nuclear Science and Technology Organisation.