For billions of years, plants have been breaking apart water molecules to store solar energy in chemical bonds. Humanity has been trying to achieve a similar feat for considerably less time, and one issue with many of our attempts is the use of the expensive and fragile material, indium tin oxide (ITO). Researchers at Duke University however, have found that films of copper nanowire could do the job as well or better, while being cheaper and more flexible.
Like it or not, ITO has proven to be a very valuable material, thanks to its conductivity and transparency, but the rarity of indium and complicated manufacturing processes make it less than ideal. This has made the search for a replacement material an important one, and copper nanowires could be it. Copper is roughly one thousand times more common than indium, making it considerably cheaper, but also copper nanowires are much cheaper to work with as they can be printed directly onto materials, such as glass or plastic. Also important is that films of copper nanowires are transparent and flexible. Even when coated with nickel or cobalt, metals useful as catalysts for separating water molecules, the nanowires allowed almost seven times more sunlight to pass through them than ITO.
Currently the nanowires have only been used for half of the water splitting process, but the researchers are working on that other half. Once that is achieved, we could eventually see copper nanowires being used to build fuel cells that will fit in backpacks and cars, or being components of OLED lights, displays, and smart glass.
Source: Duke University