Solar material removes pollutants from water

Each year, around 300,000 tonnes of harmful dye pollutants are released into the world’s water supplies. Addressing this problem is a major focus for the global textile industry.

While research into so-called photocatalytic materials (which use sunlight to break down pollutants) have long been thought promising, the efficiency of existing materials is limited as they only absorb higher energy, ultra-violet light.

Developed by a team at the University’s Energy Safety Research Institute (ESRI) the new material, a composite of tantalum nitride and tungsten oxide, is claimed to be able to remove pollutants at a far superior rate. The work is reported in Nature’s Scientific Reports journal.

The composite is synthesised by growing ultra-thin "nanowires" of tungsten oxide on the surface of tiny particles of tantalum nitride. As a result of the incredibly small size of the two material components - both the tantalum nitride and tungsten oxide are typically less than 40 billionths of a metre in diameter - the composite provides a huge surface area for dye capture.