Metal　oxides　(MOs)-based　photoelectrochemical　(PEC)　cell,　as　an　environmentally　friendly　and　sustainable　technique　to　convert　solar　energy　to　chemical　energy,　has　been　attracting　enduring　interest　in　the　past　few　decades.　However,　sluggish　charge　transport　dynamics,　tough　vectorial　controllable　charge　migration　route,　and　confined　light　absorption　of　MOs　retard　the　solar　energy　conversion　efficiencies　of　MOs-based　photoelectrodes.　Apart　from　MOs,　transition　metal　chalcogenides　(TMCs)　photoanodes　directly　growing　on　the　conductive　substrate　for　PEC　water　splitting　have　been　so　far　rarely　reported　albeit　their　generic　merits　of　large　absorption　coefficient,　suitable　energy　level　alignment,　and　abundant　active　sites.　Herein,　we　conceptually　demonstrate　the　tunable　construction　of　homogeneous　TMCs　heterostructured　photoanodes　(In2S3-CdIn2S4,　In2S3-ZnIn2S4)　by　a　facile,　easily　accessible,　simple　yet　efficient　cation　exchange　strategy　at　ambient　conditions.　The　thus-designed　TMCs　composite　photoanodes　demonstrate　significantly　enhanced　PEC　water　splitting　performances　relative　to　the　pristine　counterparts　under　both　visible　and　simulated　solar　light　irradiation,　which　is　predominantly　attributed　to　the　markedly　improved　interfacial　charge　transfer/separation　afforded　by　the　favorable　energy　level　configuration　between　the　TMCs　substrate　and　newly　formed　TMCs　phase.　We　additionally　ascertain　that　such　ion　exchange　approach　is　universal　for　crafting　other　TMCs-based　hybrid　photoanodes.　Our　work　is　expected　to　provide　an　emerging　avenue　to　craft　a　large　variety　of　TMCs-based　heterostructured　photoanodes　for　solar　energy　conversion.　©　2021　Elsevier　B.V.