Nanoporous Copper Films by Additive-Controlled Electrodeposition: CO₂ Reduction Catalysis

Electrodeposition from plating baths containing 3,5-diamino-1,2,4-triazole (DAT) as an inhibitor gives Cu films exhibiting high surface area and high CO₂ reduction activities. By changes in the pH and deposition current density, the morphologies of the Cu films are varied to exhibit wire, dot, and amorphous structures. Among these Cu films, the CuDAT-wire samples exhibit the best CO₂ reduction activities activity with a Faradaic efficiency (FE) for C₂H₄ product formation reaching 40% at -0.5 V vs RHE, a FE for C₂H₅OH formation reaching 20% at -0.5 V vs RHE, and a mass activity for CO₂ reduction at -0.7 V vs RHE of ∼700 A/g.