Spin-out to develop purification products with photocatalysts

A spin-out company from Queen’s University, Belfast is developing a variety of innovative products using advances in photocatalysts – from antibacterial plastic films and water purifying systems, to anti-pollution coatings for pavements.

The existing industry is only 20 years old, yet is already worth over $1bn annually. SunCatalyst Laboratories, headed by research fellow Dr David Hazafy aims to find applications for the university’s breakthroughs in the field, from self-cleaning paint and fabrics to glass that never fogs up. It is also providing an independent testing service to the growing industry, helping organisations such as Unilever to get their own photocatalyst innovations to market.

The technology works by using titanium dioxide that is prepared with nanoparticles to create a semiconductor. This is then used to harvest energy from ambient light in order to drive a useful chemical reaction, such as to destroy bacteria.

“The photocatalyst can be layered onto concrete, wood or fabric, amongst other things – someone is currently looking at making a self-cleaning denim,” said Hazafy. “The science behind this has been underway for over 10 years, so we have a good understanding of it. However, now we have to prove that the photocatalyst can be applied to new materials effectively as a self-cleaning agent. Its biggest application could be on skyscrapers, buildings and pavements to destroy pollutants such as nitrogen dioxide in cities, which would have a huge impact on the environment, or to combat volatile organic compounds (VOCs) in paints and lacquers. It can also be used in hospitals to make antimicrobial aprons, curtains and protective sheets.”

The technology is both cheap and reliable. The spin-out team have also been combining the titanium dioxide with different substrates for some new applications.

“Presently, around 4.5 million people in the world clean their water by placing this in a bottle and then exposing this to hours in the sun to allow the light to kill any bacteria,” Hazafy explained. “We have invented a colourmatic label to show if the water has received sufficient energy to do this. We’re also working on a plastic brush-shaped device with a high surface area that is a photocatalyst, speeding the disinfection process.”

Dr Hazafy was recently named by The Royal Academy of Engineering’s Enterprise Hub as one of the most promising inventors based in UK universities.