Metal-organic framework-derived sulfur and nitrogen dual-doped bimetallic carbon nanotubes as electrocatalysts for oxygen evolution reaction

Metal-organic frameworks (MOFs) are attracting more and more attention in the field of electrocatalysis because of their porosity, ease of adjustment and functionalization. Herein, we report the preparation of sulfur-nitrogen dual-doped Co–Fe bimetallic carbon nanotubes (CoFe@SNCN) using MOFs as precursors. The optimized CoFe@SNCN achieves a current density of 10 ​mA ​cm−2 ​at a low overpotential of 306.4 ​mV with a very small Tafel slope of 76.0 ​mV dec−1 in 1 ​M KOH, which is 64 ​mV smaller than that of Co@SNCN (370.4 ​mV) and 48 ​mV smaller than that of Fe@SNCN (354.4 ​mV). Moreover, the catalytic performance remains almost unchanged after 12 ​h. The excellent electrocatalytic performance can be attributed to the synergies between the bimetals and heteroatoms doping, which can greatly improve the electrical conductivity between the metals, promote the transfer of electrons and the exchange of substances, thereby greatly reducing the reaction kinetics and enhancing OER properties. This work may provide a very good solution for the research of a new type of highly efficient stable electrocatalytic oxygen evolution catalyst.