CeF-Accelerated surface reconstruction of MoO nanosheets into coral-like CeF/MoO composites enhances the oxygen evolution reaction for efficient water splitting.

Developing efficient and cost-effective rare earth element-based electrocatalysts for water splitting remains a significant challenge. To address this, interface engineering and charge modulation strategies were employed to create a three-dimensional coral-like CeF/MoO heterostructure electrocatalyst, grown in situ on the multistage porous channels of carbonized sugarcane fiber (CSF). Integrating abundant CeF/MoO heterostructure interfaces and numerous oxygen vacancy defects significantly enhanced the catalyst's active sites and molecular activation capabilities. The prepared coral-like CeF/MoO/CSF catalyst achieves overpotentials as low as 29 mV and 210 mV for hydrogen evolution reaction and oxygen evolution reaction at 10 mA cm current density, respectively. Notably, the CeF/MoO@CSF||CeF/MoO@CSF electrolyzer demonstrates a superior overall water splitting ability having a voltage of 1.53 V at 10 mA cm and retains outstanding stability for 100 h operating in 1.0 M KOH electrolyte. The exceptional catalytic performance of CeF/MoO@CSF is attributed to the reduction in the water dissociation energy barrier, optimal adsorption/desorption behavior of H/O intermediates, and rapid mass transfer facilitated by the multistage porous channels. These findings, supported by experimental results and density functional theory (DFT) calculations, provide a novel approach for designing rare-earth metal heterojunctions and biomass-derived synergistic electrocatalysts for efficient water splitting.