Researchers from Queensland University of Technology have discovered that gold-painted medieval stained glass windows purify the air when exposed to sunlight.
Numerous church windows across Europe were decorated by glaziers who produced colours using gold nanoparticles of varying sizes. When energised by the sun, these tiny particles can destroy airborne pollutants such as volatile organic chemicals, which can originate from new carpets, paint and furniture, and can be hazardous to health even in relatively small amounts.
Gold in very small particles becomes extremely active under sunlight, and the electromagnetic field of the sunlight couples with the oscillations of the electrons in the gold particles to create a resonance. The magnetic field of the gold nanoparticles can expand up to 100 times, breaking apart the pollutant molecules.
The use of gold nanoparticles to drive chemical reactions opens up exciting possibilities in scientific research, but a drawback is the high price of gold. The technology is solar-powered and energy efficient, because only the particles of gold heat up, unlike in conventional chemical reactions. where everything is heated up and so wastes energy.
It is hoped that eventually this technology can be applied to produce special chemicals at ambient temperatures, and could herald significant changes in the economy and environmental impact of chemical production.
