Carbonized Wood Plate Decorated with a N-Doped Carbon Nanomushroom Encapsulating FeNiS₂/(Co, Ni, Fe)₉S₈ Heteroparticle for Efficiently Catalyzing Oxygen Evolution Reaction

Abstract

Developing a high-efficiency and cost-effective electrode for the oxygen evolution reaction (OER) is imperative to the practicability for electrochemical water splitting. Inspired by the abundant resources and porosity of natural wood, herein, a hierarchical porous carbonized wood (CW) electrode decorated with hollow N-doped carbon nanomushroom (NCNM) encapsulating FeNiS 2 /(Co, Ni, Fe) 9 S 8 heteroparticle (FeCoNiS@NCNM/CW) was prepared through a one-step calcination method. Free of any conducting/binder agents, the self-supporting electrode displays superior electrocatalytic activity toward the OER in an alkaline solution with a low overpotential of 221 mV at 10 mA cm −2 and a small Tafel slope of 55.3 mV dec −1 . Moreover, favorable operation stability is presented with 92% retention of the current density after 24 h. According to experimental and theoretical results, the electronic coupling at the FeNiS 2 /(Co, Ni, Fe) 9 S 8 heterostructure interface is conducive to enhancing conductivity and accelerating the OER kinetic. Additionally, the delicate structure with the coordination of one-dimensional NCNM and threedimensional porous N/S-doped CW favors the exposure of active sites as well as ion/mass transportation, which also accounts for the superior OER performance. In view of its electrocatalytic merits together with simple synthesis, FeCoNiS@NCNM/CW is envisioned as a promising engineered electrode for future energy-related applications.