N-doped bamboo-like CNTs combined with CoFe–CoFe2O4 as a highly efficient electrocatalyst towards oxygen evolution

In this work, we developed a novel hybrid with N-doped bamboo-like carbon nanotubes combined with the CoFe alloy and its oxide (denoted as CoFe–CoFe2O4/N-CNTs) via an extremely facile one-step pyrolysis method. When applied as an electrocatalyst towards OER in 1.0 M KOH solution, CoFe–CoFe2O4/N-CNTs exhibits a small overpotential of 334 mV to afford a current density of 10 mA cm−2 associated with a low Tafel slope of 80 mV dec−1 and long-term stability. The remarkable OER electrocatalytic performance of CoFe–CoFe2O4/N-CNTs is mainly attributed to the synergistic effect between CoFe and CoFe2O4 as well as the increased active sites resulting from the introduction of N-CNTs. More impressively, the introduction of Fe can significantly cut down the usage of relatively toxic and expensive Co accompanied with the dramatic enhancement of OER electrocatalytic performance originating from the robust synergistic effect between Co and Fe.