New research has established the "miracle material" called graphene as the world's thinnest known coating for protecting metals against corrosion¹. Their study on this potential new use of graphene（石墨烯） appears in ACS Nano. In the study, Dhiraj Prasai and colleagues point out that rusting² and other corrosion of metals is a serious global problem, and intense efforts are underway to find new ways to slow or prevent it. Corrosion results from contact of the metal's surface with air, water or other substances. One major approach involves coating metals with materials that shield the metal surface, but currently used materials have limitations. The scientists decided³ to evaluate graphene as a new coating. Graphene is a single layer of carbon atoms, many layers of which are in lead pencils and charcoal⁴（木炭） , and is the thinnest, strongest known material. That's why it is called the miracle material. In graphene, the carbon atoms are arranged like a chicken-wire fence in a layer so thin that is transparent⁵, and an ounce would cover 28 football fields.

They found that graphene, whether made directly on copper⁶ or nickel or transferred onto another metal, provides protection against corrosion. Copper coated by growing a single layer of graphene through chemical vapor⁷ deposition⁸ (CVD化学蒸汽沉积) corroded⁹ seven times slower than bare copper, and nickel coated by growing multiple layers of graphene corroded 20 times slower than bare nickel. Remarkably¹⁰, a single layer of graphene provides the same corrosion protection as conventional organic coatings that are more than five times thicker. Graphene coatings could be ideal corrosion-inhibiting coatings in applications where a thin coating is favorable, such as microelectronic components¹¹ (e.g., interconnects, aircraft components and implantable devices), say the scientists.

The researchers acknowledge funding from the National Science Foundation.