Ferrocene‐Incorporated Cobalt Sulfide Nanoarchitecture for Superior Oxygen Evolution Reaction

Here, ferrocene(Fc)‐incorporated cobalt sulfide (CoxSy) nanostructures directly grown on carbon nanotube (CNT) or carbon fiber (CF) networks for electrochemical oxygen evolution reaction (OER) using a facile one‐step solvothermal method are reported. The strong synergistic interaction between Fc‐CoxSy nanostructures and electrically conductive CNTs results in the superior electrocatalytic activity with a very small overpotential of ≈304 mV at 10 mA cm−2 and a low Tafel slope of 54.2 mV dec−1 in 1 m KOH electrolyte. Furthermore, the Fc‐incorporated CoxSy (FCoS) nanostructures are directly grown on the acid pretreated carbon fiber (ACF), and the resulting fabricated electrode delivers excellent OER performance with a low overpotential of ≈315 mV at 10 mA cm−2. Such superior OER catalytic activity can be attributed to 3D Fc‐CoxSy nanoarchitectures that consist of a high concentration of vertical nanosheets with uniform distribution of nanoparticles that afford a large number of active surface areas and edge sites. Besides, the tight contact interface between ACF substrate and Fc‐CoxSy nanostructures could effectively facilitate the electron transfer rate in the OER. This study provides valuable insights for the rational design of energy storage and conversion materials by the incorporation of other transition metal into metal sulfide/oxide nanostructures utilizing metallocene. A facile and one‐step solvothermal approach is demonstrated to reform the local electronic structure of cobalt sulfide nanostructures by the incorporation of Fe‐based compounds derived from ferrocene, and nitrogen‐doped carbon nanostructures for robust oxygen evolution reaction.