Improving the electrocatalytic oxygen evolution by in situ constructing 1D Co9S8/Co(OH)F heterointerfaces

Abstract

Rationally constructing high-performance electrocatalysts for the oxygen evolution reaction (OER) is a key step to increase the efficiency of the water electrolysis system. Herein, one-dimensional (1D) Co₉S₈/Co(OH)F heterostructures were constructed through in situ hydrothermal sulfidation of Co(OH)F nanobelts. The experimental results showed that crystalline Co₉S₈ nanoparticles can be intimately grown on the surface of Co(OH)F nanobelts to form hybrid catalysts with explicit heterointerfaces. When used as an electrocatalyst for OER, the prepared Co₉S₈/Co(OH)F nanohybrid affords superior OER performance and long term stability with negligible stability delay after 12 h tests in an alkaline electrolyte. According to the physicochemical characterization, the rational integration of Co(OH)F and Co₉S₈ at the interface leads to strong interfacial electronic interaction, which can expose abundant catalytic active sites and increase the electron transfer rate for OER. Such heterointerfaces can help in modulating the functionalities of the hybrid catalysts to boost the electrocatalytic activity towards the oxygen evolution reaction.