Type-II-heterojunction　TiO2　nanorod　arrays　(NAs)　are　achieved　by　a　combination　of　reduced　and　pristine　TiO2　NAs　through　a　simple　electrochemical　reduction.　The　heterojunction-structured　TiO2　NAs　exhibit　an　enhanced　photo-efficiency,　with　respect　to　those　of　pristine　TiO2　NAs　and　completely　reduced　black　TiO2.　The　improved　efficiency　can　be　attributed　to　a　synergistic　effect　of　two　contributions　of　the　partially　reduced　TiO2　NAs.　The　light　absorption　is　significantly　increased,　from　the　UV　to　the　visible　spectrum.　Moreover,　the　type　II　structure　leads　to　enhanced　separation　and　transport　of　the　electrons　and　charges.　The　proposed　electrochemical　approach　could　be　applied　to　various　semiconductors　for　a　control　of　the　band　structure　and　improved　photoelectrochemical　performance.　©　2018　Dalian　Institute　of　Chemical　Physics,　the　Chinese　Academy　of　Sciences