The　plasmon　resonance　effect　of　the　metal　nanoparticles　is　of　great　benefit　to　improve　the　efficiency　of　solar　water　splitting.　However,　the　metal　Cu　is　easy　to　be　oxidized,　and　a　complex　transfer　process　of　hot　electrons　exits　in　Cu　/　TiO2　interfaces.　In　this　work,　the　hierarchical　Cu　/　TiO2　nanobowl　arrays　were　prepared　and　a　SiO2　interlayer　with　a　thickness　of　10　-　15　nm　was　introduced　between　the　interface　of　Cu　and　TiO2　.　The　solar　water　splitting　performances　and　the　mechanism　of　plasmonic　Cu　metal　were　investigated　by　combing　the　experiment　with　simulation.　Results　show　that　the　Cu2　O　film　formed　by　the　oxidation　of　Cu　in　Cu　/　TiO2　can　assist　the　injection　of　hot　electrons,　but　has　an　inhibitory　effect　on　the　light　absorption　of　Cu.　It　has　a　positive　effect　on　enhancing　light　absorption　and　blocking　hot　electron　migration　after　adding　the　SiO2　interlayer.　The　plasmon　energy　transfer　promotes　the　formation　of　more　photogenerated　electron-hole　pairs.　Therefore,　the　Cu　/　SiO2　/　TiO2　nanobowl　arrays　exhibit　the　enhanced　photoelectrochemical　performance.　©　2023　Beijing　University　of　Technology.　All　rights　reserved.