Stained glass windows as air purifiers

Gold nanoparticles in medieval stained glass windows serve as air purifiers.

“For centuries people appreciated only the beautiful works of art, and long life of the colors, but little did they realize that these works of art are also, in modern language, photocatalytic air purifier with nanostructured gold catalyst,” said Zhu Huai Yong, a material scientist at the Queensland University of Technology.

When energized by the sun, tiny gold particles can destroy certain airborne pollutants. These pollutants, called volatile organic compounds, create the “new” smell often detected in new furniture, carpets and paint in good condition. Even in small amounts, these compounds, like methanol and carbon monoxide, are not good for your health.

An electromagnetic field generated by sunlight couples with the gold electrons’ oscillations to create a resonance, said Zhu. The magnetic field of the gold nanoparticles can expand up to hundred times, breaking apart the pollutant molecules.