Associate Professor Zhu Huai Yong, from QUT's School of Physical and Chemical Sciences, said that glaziers in medieval forges were the first nanotechnologists who produced colours with gold nanoparticles of different sizes.
Zhu said numerous church windows across Europe were decorated with glass coloured with gold nanoparticles: "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 purifiers with nanostructured gold catalysts."
According to Zhu, tiny particles of gold, energised by the sun, were able to destroy airborne pollutants like volatile organic chemicals (VOCs), which may often come from new furniture, carpets and paint in good condition.
"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," he said. "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 a hundred times, which breaks apart the pollutant molecules in the air."
Zhu said that the by-product of the process was carbon dioxide, which was comparatively safe, particularly in the small amounts that would be created through this process. The use of gold nanoparticles to drive chemical reactions has 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. "In conventional chemical reactions, you heat up everything, which is a waste of energy. Once this technology can be applied to produce specialty chemicals at ambient temperature, it heralds significant changes in the economy and environmental impact of the chemical production."
For further information, contact: Queensland University of Technology, GPO Box 2434, Brisbane, QLD 4001, Australia; Internet: www.qut.edu.au
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