Superhydrophobic and Conductive Wire Membrane for Enhanced CO₂ Electroreduction to Multicarbon Products

Gas-liquid-solid triple-phase interfaces (TPI) are essential for promoting electrochemical CO₂ reduction, but it remains challenging to maximize their efficiency while integrating other desirable properties conducive to electrocatalysis. Herein, we report the elaborate design and fabrication of a superhydrophobic, conductive, and hierarchical wire membrane in which core-shell CuO nanospheres, carbon nanotubes (CNT), and polytetrafluoroethylene (PTFE) are integrated into a wire structure (designated as CuO/F/C(w); F, PTFE; C, CNT; w, wire) to maximize their respective functions. The realized architecture allows almost all CuO nanospheres to be exposed with effective TPI and good contact to conductive CNT, thus increasing the local CO₂ concentration on the CuO surface and enabling fast electron/mass transfer. As a result, the CuO/F/C(w) membrane attains a Faradaic efficiency of 56.8 % and a partial current density of 68.9 mA cm^-2 for multicarbon products at -1.4 V (versus the reversible hydrogen electrode) in the H-type cell, far exceeding 10.1 % and 13.4 mA cm^-2 for bare CuO.