Interfacial engineering of Copper(I) oxide nanocubes wrapped with functionalized carbon nanotubes toward carbon dioxide electroreduction to ethylene

Copper(I) oxide (Cu2O)-based nanomaterial is considered to be a highly attractive electrocatalyst for the carbon dioxide (CO2) reduction to ethylene (C2H4), while the selectivity of C2H4 still faces challenges. Herein, a unique nanocomposite consisted of Cu2O nanocubes trapped with oxygen-containing groups functionalized carbon nanotubes (O-CNTs) through a facile wet chemical method is reported. Benefiting from the novel structure and robust interface, the nanocomposite (Cu2O/O-CNTs) electrocatalyst exhibits an enhanced C2H4 selectivity (Faradic efficiency = 40.3%) at -1.3 V vs. RHE, a current density of 13.6 mA/cm2, and long-term durability (over 8 h) in KHCO3 electrolyte. The O-CNTs trapping around Cu2O nanocubes with an intimately interface ensures highly conductive network and uniform dispersion of active sites in the electrochemical CO2 reduction reaction (ECO2RR). The improved performance of Cu2O/O-CNTs can be attributed to the rapid mass transport, increased local concentration of *CO intermediates, and stable heterointerface. This study presents a new route to increase the performance and cyclic lifetime of Cu-based catalyst for CO2 electroreduction to C2H4 by the trapping interfacial engineering.