Carbon/platinum nanotextured films produced by plasma sputtering

Platinum loaded carbon layers were synthesized by a two-step plasma sputtering process. Two hundred nanometers thick columnar (columns with an average diameter of 20 nm) carbon films having a large open porosity were formed in the first step. Using the same plasma system, the films were subsequently loaded with platinum. SEM, TEM and Rutherford backscattering spectrometry analysis show that platinum diffuses into the carbon layer and forms nano-sized particles (mean diameter ca. 3 nm) along and around the carbon nanocolumns and down to the film/support interface. Optimized catalytic layers were formed at low plasma pressure operation (<1 Pa) and had an upper platinum loading limit of about 0.1 mg cm−2.