While Alcoa’s photocatalytic panels offer architects the possibility of creating buildings that can help reduce impurities in the air around them, Italian artist Andreco has come up with a different use of the technology that may be more aesthetically appealing. His Philosophical Tree mural installed in Bologna uses paint that helps to tackle smog in the city. Created as part of the Frontier Project, which aims to investigate new forms of street art, Andreco painted the 59-feet-high piece on the side of a five-storey building, using photocatalytic paint that absorbs nitrogen monoxide, otherwise known as smog, in the atmosphere. Similar in many ways to the “Respira” project we saw earlier this year, the Philosophical Tree also demonstrates that environmentally friendly initiatives need not be an eye sore on the surrounding area. The work could provide inspiration for local authorities looking to kill two birds with one stone when commissioning new public works. One for forward-thinking public officials? Spotted by: Murray Orange