A team of experts at Queensland University of Technology have found that stained glass windows – the ones painted with gold – help purify the air when lit up with sunlight. People in medieval times were already using nanotechnology to produce colors with gold nanoparticles of different sizes. Numerous church windows across Europe were decorated with glass painted with gold nanoparticles. For centuries, people have appreciated the beautiful works of art, but little did they know that these windows also made the air cleaner!

The tiny gold particles would be energized by the sun and were able to destroy pollutants in the air. Sunlight enhances the magnetic field on the nanoparticles up to 100 times, which causes nearby pollutant molecules in the air to break apart. This process produces small amounts of carbon dioxide, which is safe and environmentally friendly. Since this technology is solar-powered, it opens a lot of exciting possibilities for scientific research in renewable energy!

Source: Air-purifying Church Windows Were Early Nanotechnology