Gas Flow Sputtering of Pt/C Films and their Performance in Electrocatalytic Hydrogen Evolution Reaction

A single step deposition technique of Pt/C films for electrocatalytic applications is presented. The hollow cathode gas flow sputtering (GFS) method allows a catalyst production within few minutes without further steps. The herein presented films consist of small Pt nanocrystals (2-5 nm) deposited in a matrix of nanocrystalline carbon. The films show a low and stable overpotential under acidic conditions in the hydrogen evolution reaction (HER). Relatively low Pt-mass activity (<1 mA/μg_Pt ) is attributed to the yet too high Pt-content in the films. Another issue discovered in this work is a non-graphitic state of carbon resulting in its high resistivity. Still, the GFS deposition technique providing by nature high deposition rates and a substance-to-material yield of 80-90 % is advantageous than other sputtering techniques and especially chemical methods in that sense. This technique is scalable to areas in the range of square meters and thus represents an attractive way to efficiently produce large-scale cathode coatings for industrial electrolysers.