Efficient oxygen evolution electrocatalyzed by a Cu nanoparticle-embedded N-doped carbon nanowire array

Development of efficient and durable catalysts based on earth-abundant elements for oxygen evolution reactions (OER) is important for renewable energy storage and conversion technologies. Herein, we report the development of a Cu nanoparticle-embedded N-doped carbon nanowire array on copper foam (Cu-N-C NA/CF) via carbonization of a Cu(TCNQ) (TCNQ = 7,7,8,8-tetracyanoquinodimethane) nanoarray. As a 3D OER electrode, this Cu-N-C NA/CF shows high catalytic activity, needing an overpotential of 314 mV to drive a geometrical current density of 20 mA cm(-2) in 1.0 M KOH. It also shows strong long-term electrochemical durability. This suggested that CuO nanoparticles as active species were in situ electrochemically converted from Cu nanoparticles and stably dispersed in the carbon matrix during electrocatalysis.