Ecological relevance for chemical double act

European researchers developing ’smart’ construction materials capable of reducing air pollution are awaiting the first results of their latest studies using environmentally ’relevant’ pollutant combinations.

The work forms part of the PICADA (Photocatalytic Innovative Coverings Applications for Depollution Assessment) project, a European consortium of private companies, research institutes, and the European Commission’s Joint Research Centre (JRC). The construction materials being tested contain photocatalytic TiO₂ nanoparticles, which adsorb common air pollutants, such as nitrogen oxides (NO_x) and, following UV activation, convert those pollutants to relatively harmless products that can then be washed away.

Work to date has examined the response of these materials to single pollutants; NO_x or organic compounds like benzene. ’What we are doing now is to expand these activities to mixtures of compounds, such as benzene and NO _x together,’ says Dimitris Kotzias, head of the JRC’s Physical and Chemical Exposure Unit. Surprisingly, this wasn’t on the original PICADA plans. ’Looking at these mixtures is more relevant to photochemical smog,’ says Kotzias, ’and in particular for the degradation and/or elimination of ozone precursors.’

Past results using single pollutants have been very encouraging, he says. The results of these latest trials on pollutant mixtures are not expected until the beginning of April.

Bea Perks