Contacts: Dr. Vasant Kumar, Giorgio Divitini, Dr. Caterina Ducati & Najeeb Ullah, Materials Science & Metallurgy
Mentor: Dr. Mark Priest

Sunlight can degrade pollutants in water with a suitable catalyst. Current solutions exist, with the most common catalyst being Titanium dioxide particles. These have the advantage of working with sunlight, with no need for an external power source, so the pollutant removal can take place off-grid and is cheap to operate. It is also a low-tech approach – simply mix the particles into the polluted water, expose to sunlight and wait.

However, the currently-available catalysts only exploit the ultraviolet part of the spectrum, resulting in a slow degradation process which is slowed further by cloudy weather conditions.

A team of researchers from the Department of Materials Science & Metallurgy have developed a new sunlight-activated catalyst which is active in the visible range of the spectrum. This means that its reaction speed is 10-100x as fast as that of catalysts like titanium dioxide, since more of the sunlight’s energy is used. It can also work in low light conditions including cloudy weather and indoors (using ambient sunlight and/or artificial light).


Clearly this new patent-pending catalyst has a wide range of uses for water purification and pollutant removal, many of which currently use filtration as the preferred purification technique. Some examples include the market for textile dyes, where 0.7 million tons of dyes are produced every year worldwide, with 10% being released in the effluents; purification of drinking water without the need for a power source or replacement filters; and a low cost, zero power solution for the purification of air inside buildings.

The question for the i-Team is to look at a wide range of possible uses for the new catalyst, and assess where its unique benefits give the greatest advantage over existing techniques. In the case of solutions for the developing world, such as water purification, the team may also need to look at appropriate partnerships and sources of funding to enable the technology to get to the people who need it.