Synergistic Fe and nitrogen-doped carbon nanotubes boost bifunctional water splitting of wood-derived Co electrocatalysts at high current density

Abstract

This study addresses the critical scientific challenges of strong intermediate adsorption and high mass transfer resistance in wood-derived Co-based electrocatalysts at high-current-density HER/OER water splitting. We propose a synergistic regulation strategy combining Fe doping and nitrogen-doped carbon nanotubes (NCNTs), achieving simultaneous breakthroughs in electron transport path optimization and mass diffusion kinetics enhancement through d-band center modulation of Co and construction of a three-dimensional interperforated channel network. The obtained Fe–Co@NCNT/CW electrode exhibits exceptional bifunctional performance: at a high current density of 500 mA cm⁻² (800 mA cm⁻²), the HER/OER overpotentials are as low as 305 mV (368 mV) and 411 mV (440 mV), respectively, demonstrating excellent long-term stability. This work establishes a theoretical and technological foundation for the high-value utilization of agricultural and forestry waste and the advancement of clean energy technologies.