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

Currently, there are still many limitations in the research of conductive metal-organic frameworks (MOFs) in the field of electrocatalysis. On the one hand, most MOFs have a solid construction, seriously hindering their mass transfer process. On the other hand, innate bonding is not conducive to the optimization of electronic structures and the excitation of intrinsic active sites. Therefore, external/internal dual-control of MOFs is urgently needed to break the shackles of their activity. Herein, the hollow RuCoCu-MOF/CF nanorods with tunable cavities are directionally constructed by a self-sacrificial template method. Benefiting from the exact morphological control and the unique Ru–O–Co bond bridge, RuCoCu-MOF/CF exhibits 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.