Medieval church windows helped purify air

A new study suggests that medieval stained glass windows covered with tiny gold particles helped to purify the air when sunlight shone through them.

Zhu Huai Yong, a material scientist at the Queensland University of Technology, believes that the gold nanoparticles can destroy airborne pollutants such as methanol and carbon monoxide. "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," he said.