Different　numbers　of　N/Ti3+　codoped　triphasic　TiO2　layer　are　deposited　on　TiO2　nanotube　arrays　by　hydrothermal　reaction　of　TiN　and　TiO2　nanotube　arrays.　The　crystal　structure,　morphology,　and　composition　of　the　as-prepared　samples　and　their　photoelectrochemical　properties　are　investigated　and　discussed.　There　are　obviously　red　shift　of　the　optical　edge　and　enhanced　visible　light　absorption　for　the　resulting　samples　in　the　ultraviolet-visible　diffuse　reflectance　spectroscopy.　Besides,　the　photoelectrochemical　tests　indicate　that　the　N/Ti3+　codoped　triphasic　TiO2-TiO2　nanotube　array　samples　exhibit　an　enhanced　photocurrent　density　and　photovoltage　under　visible　light　irradiation.　The　maximum　photoconversion　efficiency　of　N/Ti3+　codoped　triphasic　TiO2-TiO2　nanotube　array　sample　is　2.1　times　higher　than　that　of　pristine　TiO2　nanotube　arrays.　In　addition,　reduced　impedance,　higher　carrier　density,　and　excellent　stability　of　photoelectrochemical　performance　of　N/Ti3+　codoped　triphasic　TiO2-TiO2　nanotube　array　samples　are　also　demonstrated.　Finally,　a　plausible　mechanism　for　the　charge　migration　and　separation　on　N/Ti3+　codoped　triphasic　TiO2-TiO2　nanotube　array　samples　is　proposed.　This　study　provides　a　novel　strategy　to　design　and　fabricate　visible-light-driven　TiO2　based　composites　and　promote　their　applications　in　the　field　of　solar　energy　utilization.　(c)　2018　Elsevier　Ltd.　All　rights　reserved.