High　quality　ternary-alloyed　CdTeSe　quantum　dots　(QDs)　have　been　synthesized　via　a　simple　one-pot　approach　in　aqueous　phase.　CdTeSe　QDs　show　an　average　size　of　3.0 nm　with　good　crystallinity,　excellent　monodispersity　and　relatively　narrow　size　distribution.　TiO2　nanotubes　(TNTs)　were　prepared　by　hydrothermal　method　with　larger　specific　surface　area　(364.2 m2 g−1),　and　CdTeSe@TNTs　were　synthesized　by　in　situ　process.　The　absorption　edge　of　CdTeSe@TNTs　is　red　shifted　significantly　toward　697 nm.　After　sensitized　with　CdTeSe,　the　photoluminescence　(PL)　emission　of　CdTeSe@TNTs　is　significantly　quenched,　and　the　fluorescence　lifetime　of　the　composites　is　drastically　decayed　from　105.82 ns　to　0.13 ns　with　a　high　photoinduced　electron　transfer　rate　(ket = 7.98 × 109 s−1)　because　of　their　high　matchable　lattice　constant.　In　addition,　under　visible-light　irradiation,　the　photocatalytic　efficiency　of　rhodamine　B　(RhB)　with　CdTeSe@TNTs　reaches　90%　for　80 min.　And　the　photocatalytic　reaction　rate　constant　for　CdTeSe@TNTs　is　0.0272 min−1,　which　is　5.4　and　3.4　times　larger　than　that　of　pure　TNTs　and　CdTeSe　QDs,　respectively.　It　is　due　to　the　broad　visible　absorption　of　CdTeSe@TNTs　and　the　faster　photoinduced　electron　transfer　from　CdTeSe　QDs　to　TNTs.　©　2016　Elsevier　B.V.