Huq, Faria, et al. ChemElectroChem, 2022, 9(1), e202101279.
Gas diffusion electrode (GDE) was prepared by sputtering metal (copper) film on polytetrafluoroethylene (PTFE) membrane, which can be used as a highly efficient electrode for electrochemical reduction of CO2 (CO2 R). It was found that the thickness of PTFE membrane used in GDE fabrication plays a crucial role in the electrode performance. On thinner membranes, CO2 R is the dominant process, while on thicker membranes, H2 formation is promoted.
Preparation procedure of Cu-PTFE
· Using a commercial DC-magnetron co-sputter system with specific sputter parameters, copper with a purity of 99.99% was deposited onto commercially available porous PTFE membranes.
· Three different types of PTFE membranes were used: 25-51 μm, 75 μm, and 203-305 μm, all having similar pore sizes of 0.45 μm, 0.5 μm and 0.45 μm, respectively.
· The substrates were all coated simultaneously. To ensure a base vacuum better than 5×10-4 Pa, the holder was connected to a membrane and a turbo molecular high vacuum pump in the sputter chamber.
· Cu sputtering was done simultaneously on all three membrane types with the sputter cathode positioned 11 cm away from the substrate. To prevent the membrane from rolling up due to tensile stress during sputtering, a narrow Cu ring was used to weigh down the membranes. The sample holder was continuously rotated at 10 rpm to ensure a uniform Cu coating.
Chia-Lien Lu, et al. Renewable Energy, 219, 134, 982-988.