Chemists from Queensland University of Technology (QUT), Australia, have found that the air in medieval European churches was purified by gold nanoparticles used to paint their stained glass windows. As said the team leader, 'glaziers in medieval forges were the first nanotechnologists.' [This is not completely true: nanocosmetics were used since the Pharaohs and Renaissance potters also were early nanotechnologists.] Anyway, when the gold nanoparticles are energized by the sun, they are able to destroy air-borne pollutants like volatile organic chemical (VOCs), which may often come from paint. The research team expects that this will help to develop more cost-effective and eco-friendly chemicals at room temperature. But read more...
You can see on the left a photo of the team leader of this project, Huai Yong Zhu, an associate professor in the School of Physical and Chemical Sciences who said that "For centuries people appreciated only the beautiful works of art, and long life of the colours, but little did they realise that these works of art are also, in modern language, photocatalytic air purifier with nanostructured gold catalyst." (Credit: QUT) Here is a list of his recent publications.
And here are some additional quotes from Zhu Huai Yong. "These VOCs create that 'new' smell as they are slowly released from walls and furniture, but they, along with methanol and carbon monoxide, are not good for your health, even in small amounts. 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."
According to Zhu, the only byproduct is carbon dioxide, which is created in relatively small amounts by the process, and which is not as harmful as the VOCs that the nanoparticles eliminate. Zhu also thinks that the use of gold nanoparticles to drive chemical reactions is very energy efficient because the technology is solar-powered.
Sources: Queensland University of Technology, Australia, August 21, 2008; and various websites
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