External and Internal Dual-controls: Tunable Cavity and Ru-O-Co Bond Bridge Synergistically Accelerate the RuCoCu-MOF/CF Nanorods for Urea- assisted Energy-saving Hydrogen Production

Abstract Currently, conductive metal-organic frameworks (MOFs) with the merits of porosity and large specific surface area have prodigious development prospects in the field of electrocatalysis. However, the regulation of the cavity of the hollow MOFs and its research on the performance of urea-assisted water splitting are still challenges. Toward this aim, the hollow RuCoCu-MOF/CF nanorods with tunable cavities are directionally constructed by a self-sacrificial template strategy. Benefiting from the innovative morphological control and the unique Ru-O-Co bond bridge, RuCoCu-MOF/CF has superior performances for alkaline hydrogen evolution reaction (HER) and urea oxidation reaction (UOR). Surprisingly, a record-breaking voltage of 1.402 V drives a current density of 10 mA cm− 2 for urea-assisted overall water splitting under alkaline conditions, greatly promoting the development of energy-efficient hydrogen production technology. This work firstly constructed the MOF-based self-supporting electrode with ultra-high urea-assisted hydrogen production and urea degradation performances via the dual controls of the cavity size and chemical bond bridge. This points out the direction for the development of unique integrated electrodes for both hydrogen production and decontamination.