Influence of sputtering parameters on electrochemical CO2 reduction in sputtered Au electrode

Electrochemical CO2 reduction was studied in KCl and KHCO3 using a Au electrode prepared by sputtering. We investigated the influence of the sputtering parameters (rf power, Ar pressure during deposition, and the distance between substrate and target) and thickness on the reduction potential and products, CO and H2. In KCl, the reduction potential, i.e. the overvoltage, was influenced by the Ar pressure, which affects the Au surface geometrical structure/surface area, while in KHCO3, the potential remained almost constant, probably due to the neutralizing capacity of KHCO3. The other sputtering parameters did not change the CO2 reduction behavior appreciably.