Gold is widely used in components of products such as smartphones.
A team of Chinese researchers have turned the inexpensive metal copper into a new material “almost identical” to gold, according to a study published in peer-reviewed journal Science Advances on Saturday.
The discovery will greatly reduce the use of rare, expensive metals in factories, said the authors. Professor Sun Jian and colleagues at the Dalian Institute of Chemical Physics, at the Chinese Academy of Sciences in Liaoning, shot a copper target with a jet of hot, electrically charged argon gas.
The fast-moving ionised particles blasted copper atoms off the target. The atoms cooled down and condensed on the surface of a collecting device, producing a thin layer of sand-like material.
Each grain of the sand had a diameter of only a few nanometres, or a thousandth of the size of a bacterium. The researchers put the material in a reaction chamber and used it as a catalyst to turn coal to alcohol, a sophisticated and difficult chemical process that only precious metals can handle efficiently.
Copper has a similar weight and look to gold. For centuries it has attracted alchemists who saw it as a gateway to instant riches. The new material created by Sun’s lab cannot be used to make fake gold pennies.
Its density remains the same as ordinary copper. But the process could prove valuable and provide a significant boost for Chinese industries, according to the researchers.
Precious metals remain central to modern economies. The components of electronic devices, for instance, contain a large amount of gold, silver and platinum. About 40 smartphones can contain as much gold as a tonne of ore, it has been estimated.
Copper cannot function as well as gold in industrial applications, mainly because there are fewer electrons – subatomic particles with negative charge – buzzing around its nucleus. These electrons are also relatively unstable, so copper tends to react more easily when combining with other chemicals.
The method developed by Sun’s team can inject a large amount of energy into copper atoms and make the electrons more dense and stable, they said. The new material can resist high temperatures, oxidisation and erosion, according to the researchers. It is “like a warrior with golden armour in a battlefield, capable of withstanding any enemy assault”, they said.