Engineering the novel two-dimensional MoCoFe hybrid nanoarray electrodes derived from metal-organic frameworks for highly efficient electrocatalytic oxygen evolution

Abstract

The serious concern about energy shortage and environmental pollution requires the development of next-generation energy storage and conversion equipment. People have made tremendous efforts in developing alternative electrode materials (like metal oxides, hydroxides, or their compound materials) for water electrolysis. Among them, polymetallic organic framework nanostructures have attracted much attention. Metal-organic frameworks (MOFs) have undergone a topological transformation and surface reconstruction, and the multi-metal coupling effect could significantly improve the performance of oxygen evolution reaction (OER), providing another way to obtain effective catalysts. In this study, a highly active two-dimensional (2D) MoCoFe hybrid nanosheets derived from MOFs (MoCoFe@NC) was prepared as an electrocatalyst for OER. Given the synergistic effect between 2D nanosheet structure and polymetallic electronic modification, it provides highly dispersed and accessible active sites for electrochemical reactions. At the same time, nitrogen doping and the formation of metal sulfide hybrid products on the carbon substrate improve the conductivity, showing the potential of bifunctional electrocatalysts. In alkaline electrolytes, the electrocatalyst reveals an initial potential of 1.45 V and only requires an overpotential of 285 mV to reach a current density of 10 mA cm−2 and has good endurance. It still exhibits excellent activity after continuous operation for 20,000 s. These findings not only contribute theoretical support to the correlation between polymetallic coordination structure evolution and OER catalytic activity in compound materials but also offer prospects for the development of hybrid electrocatalysts.