Hollow N-doped carbon nano-mushroom encapsulated hybrid Ni3S2/Fe5Ni4S8 particle anchored to the inner wall of porous wood carbon for efficient oxygen evolution electrocatalysis

Abstract

Structural design and morphology engineering are considered significant strategies to boost the catalytic performance of electrocatalysts toward the oxygen evolution reaction. Inspired by the natural porosity and abundant functional groups, herein, hollow N-doped carbon nano-mushroom (NCNM) encapsulated hybrid sulfide particles rooted into a carbonized wood (CW) framework were prepared through simple impregnation followed by calcination. The as-prepared self-supporting electrodes present ultrahigh activity and robust stability. Among them, the NiFeS14@NCNM/CW catalyst yields incredible OER activity with an extraordinarily low overpotential of 147 and 250 mV to reach 10 and 50 mA cm⁻², respectively, superior to most of the state-of-the-art wood-derived electrocatalysts. Additionally, a steady OER current density is maintained without obvious attenuation after continuous operation for 24 h. The superior electrocatalytic performance of NiFeS14@NCNM/CW is attributed to the synergistic effect of hybridization between Ni₃S₂ and Fe₅Ni₄S₈, the coordination of one-dimensional (1D) NCNMs and hierarchical three-dimensional (3D) porous CW, modified electronic states by N and S doping, a large electrochemical surface area, and low activation energy. This research provides a novel approach to industrial-scale conversion of abundant biomass into efficient binder-free electrocatalysts for energy-related applications.