Fe/Co‐based Bimetallic MOF‐derived Co3Fe7@NCNTFs Bifunctional Electrocatalyst for High‐Efficiency Overall Water Splitting

Electrocatalytic water splitting to produce hydrogen and oxygen is regarded as one of the most promising methods to generate clean and sustainable energy for replacing fossil fuels. However, the design and development of an efficient bifunctional catalyst for simultaneous generation of hydrogen and oxygen remains extremely challenging yet is critical for the practical implementation of water electrolysis. Here, we report a facile method to fabricate novel N‐doped carbon nanotube frameworks (NCNTFs) by the pyrolysis of a bimetallic metal organic framework (MIL‐88‐Fe/Co). The resultant electrocatalyst, Co3Fe7@NCNTFs, exhibits excellent oxygen evolution reaction (OER) activity, achieving 10 mA/cm2 at a low overpotential of just 264 mV in 1 M KOH solution, and 197 mV for the hydrogen evolution reaction. The high electrocatalytic activity arises from the synergistic effect between the chemistry of the Co3Fe7 and the NCNTs coupled to the novel framework structure. The remarkable electrocatalytic performance of our bifunctional electrocatalyst provides a promising pathway to high‐performance overall water splitting and electrochemical energy devices. The resultant bifunctional electrocatalyst, Co3Fe7@NCNTFs, exhibits excellent oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) activity. It only needs a low overpotential of 264 mV and 197 mV to reach a current density of 10 mA/cm2 in 1 M KOH solution for OER and HER, respectively. This bifunctional electrocatalyst also shows high‐efficiency overall water splitting performance with 10 mA/cm2 at a cell voltage of 1.64 V, which is slightly higher than state‐of‐the‐art Pt/C||RuO2 electrode (1.61 V).