Replacing　the　anodic　oxygen　evolution　reaction　in　water　electrolysis　with　thermodynamically　more　favorable　oxidation　reactions　is　appealing　for　reducing　the　energy　consumption　of　hydrogen　production　but　is　limited　by　the　lack　of　efficient　yet　cost-effective　electrodes.　Herein,　a　self-supporting　NiFe-based　Prussian　blue　analogue　(PBA)　electrode　(NiFe-PBA-NF)　was　directly　prepared　via　a　facile　semi-sacrificial　anodic　electrodeposition　strategy,　in　which　ultrasmall　NiFe-PBA　nanoparticles　were　grown　uniformly　and　compactly　on　the　nickel　foam　(NF)　surface.　Benefiting　from　its　ingenious　structure　and　the　synergistic　effect　between　Ni　and　Fe　sites,　the　as-prepared　NiFe-PBA-NF　exhibited　excellent　electrochemical　performance　in　the　urea　oxidation　reaction　(UOR)　with　a　required　potential　of　only　1.375　V　to　deliver　a　current　density　of　100　mA　cm−2,　outperforming　the　powdered　NiFe-PBA　and　even　the　commercial　RuO2　catalyst.　Moreover,　a　Ru-NiFe-PBA-NF　electrode　assembled　with　ultrathin　Ru-doped　NiFe-PBA　nanosheets　was　fabricated　through　further　Ru-modification　treatment,　which　exhibited　a　remarkable　electrochemical　performance　in　the　hydrogen　evolution　reaction　(HER),　even　better　than　that　of　the　commercial　Pt/C　catalyst.　Ultimately,　a　UOR-coupled　energy-saving　hybrid　water　electrolysis　system　was　constructed　by　employing　Ru-NiFe-PBA-NF　and　NiFe-PBA-NF　as　the　electrodes　for　the　cathodic　HER　and　anodic　UOR,　respectively,　which　only　requires　a　cell　voltage　of　1.36　V　to　deliver　a　current　density　of　10　mA　cm−2,　far　superior　to　a　conventional　water　electrolysis　system.　This　work　provides　a　novel　way　to　design　advanced　organic-inorganic　hybrid-based　electrodes　and　innovative　water　electrolysis　systems　for　efficient　hydrogen　production.　©　2023　The　Royal　Society　of　Chemistry.