A new method for quickly and cheaply depositing ultra-thin layers of platinum might make it practical to reduce the amount of the metal used in fuel-cell catalysts, thereby lowering their cost significantly.
Current methods for applying atom-thick layers of platinum—mainly, atomic layer deposition—are slow and complicated. The new approach is cheap and easy to implement, according to the National Institute of Standards and Technology. Essentially, platinum dissolved in a solution is deposited in single-atom-thick layers by alternately applying positive and negative voltages. Repetition can quickly and easily build layers of any desired atomic thickness. Shown here is a scanning tunneling microscope image of an ultrathin film layer of platinum deposited on gold after five seconds. Darker areas are exposed gold substrate not yet covered by the platinum.