CeF3-Accelerated surface reconstruction of MoO2 nanosheets into coral-like CeF3/MoO2 composites enhances the oxygen evolution reaction for efficient water splitting.

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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 CeF3/MoO2 heterostructure electrocatalyst, grown in situ on the multistage porous channels of carbonized sugarcane fiber (CSF). Integrating abundant CeF3/MoO2 heterostructure interfaces and numerous oxygen vacancy defects significantly enhanced the catalyst's active sites and molecular activation capabilities. The prepared coral-like CeF3/MoO2/CSF catalyst achieves overpotentials as low as 29mV and 210mV for hydrogen evolution reaction and oxygen evolution reaction at 10mA cm-2 current density, respectively. Notably, the CeF3/MoO2@CSF||CeF3/MoO2@CSF electrolyzer demonstrates a superior overall water splitting ability having a voltage of 1.53V at 10mA cm-2 and retains outstanding stability for 100h operating in 1.0M KOH electrolyte. The exceptional catalytic performance of CeF3/MoO2@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.