TiO2　nanotube　arrays　were　fabricated　by　sonoelectrochemical　anodic　oxidation　and　calcined　in　nitrogen,　air,　or　5%　hydrogen/nitrogen　which　was　denoted　as　TNT-A,　TNT-N,　and　TNT-H,　respectively.　All　annealed　TiO2　nanotube　arrays　samples　exhibited　similar　surface　morphology.　With　UV　illumination　(365　+/-　15　nm),　the　photocurrent　density　of　the　TNT-A,　TNT-N　and　TNT-H　was　about　0.27　mA/cm(2),　0.45　mA/cm(2)　and　0.60　mA/cm(2),　respectively.　The　trapped　electron　at　the　Ti4+　center　of　TiO2　nanotube　arrays　shows　absorption　at　around　500-700　nm.　From　the　XPS　measurement,　it　was　found　that　annealing　in　5%　hydrogen/nitrogen　helped　the　sample　obtain　a　greater　defect　density.　Because　of　the　reduction　of　Ti4+　and　the　formation　of　oxygen　vacancies,　the　charge　transfer　resistance　appeared　in　this　order:　TNT-A　＞　TNT-N　＞　TNT-H.　Thus　TNT-H　harvested　the　greatest　charge　carrier　density　of　9.86　x　10(20)　cm(-3),　TNT-N　and　TNT-A　obtained　a　charge　carrier　density　of　1.38　x　10(20)　cm(-3)　and　1.06　x　10(20)　cm(-3),　respectively.　Accordingly,　the　hydrogen　production　rate　by　water　splitting　over　TNT-A,　TNT-N　and　TNT-H　(320-780　nm　irradiation,　3　h)　was　about　120　mu　L/h　cm(2),　159　mu　L/h　cm(2)　and　231　mu　L/h　cm(2),　respectively.　Copyright　(C)　2011,　Hydrogen　Energy　Publications,　LLC.　Published　by　Elsevier　Ltd.　All　rights　reserved.