A　hierarchical　sea　urchin-like　hybrid　metal　oxide　nanostructure　of　ZnO　nanorods　deposited　on　TiO2　porous　hollow　hemispheres　with　a　thin　zinc　titanate　interface　layer　is　specifically　designed　and　synthesized　to　form　a　combined　type　I　straddling　and　type　II　staggered　junctions.　The　HHSs,　synthesized　by　electrospinning,　facilitate　light　trapping　and　scattering.　The　ZnO　nanorods　offer　a　large　surface　area　for　improved　surface　oxidation　kinetics.　The　interface　layer　of　zinc　titanate　(ZnTiO3)　between　the　TiO2　HHSs　and　ZnO　nanorods　regulates　the　charge　separation　in　a　closely　coupled　hierarchy　structure　of　ZnO/ZnTiO3/TiO2.　The　synergistic　effects　of　the　improved　light　trapping,　charge　separation,　and　fast　surface　reaction　kinetics　result　in　a　superior　photoconversion　efficiency　of　1.07%　for　the　photoelectrochemical　water　splitting　with　an　outstanding　photocurrent　density　of　2.8　mA　cm−2　at　1.23　V　versus　RHE.　©　2024　The　Author(s).　Published　by　IOP　Publishing　Ltd.