Medieval stained glass windows acted like nano air purifiers

I wonder if these people knew what they were doing or if they fluked it? If they knew about it this will be an even more amazing find
story

Stained glass windows in churches dotting Europe and painted with gold purified the air when lit up by sunlight, according to Queensland University of Technology experts.

'For centuries, people appreciated only the beautiful works of art, and long life of the colours, but little did they realise that these works... are also... photocatalytic air purifier with nanostructured gold catalyst,' said Zhu Huai Yong, of Queensland's School of Physical and Chemical Sciences.

Thanks for the anon S&F. I appreciate it, but would also like a comment or two. Not for the sake of the thread, but to see if anyone has any further insite to this phenomenon. Could there be additional applications to this I wonder?

Some more of the story to contemplate....

'Gold, when in very small particles, becomes very active under sunlight.

'The electromagnetic field of the sunlight can couple with the oscillations of the electrons in the gold particles and creates a resonance.

'The magnetic field on the surface of the gold nanoparticles can be enhanced by up to hundred times, which breaks apart the pollutant molecules in the air.'

Zhu said the by-product was carbon dioxide, which was comparatively safe, particularly in the small amounts that would be created through this process.

He said the use of gold nanoparticles to drive chemical reactions opened up exciting possibilities for scientific research.

'This technology is solar-powered, and is very energy efficient, because only the particles of gold heat up,' he said.