Metal　sulfide-based　homojunction　photocatalysts　are　extensively　explored　with　improved　photocatalytic　performance.　However,　the　construction　of　metal　sulfide-based　S-scheme　homojunction　remains　a　challenge.　Herein,　the　fabrication　of　2D　CdIn2S4　nanosheets coated　3D　CdIn2S4　octahedra　(referred　to　as　2D/3D　n-CIS/o-CIS)　S-scheme　homojunction　photocatalyst　is　reported　by　simply　adjustment　of　polyvinyl　pyrrolidone　amount　during　the　solvothermal　synthesis.　The　formation　of　S-scheme　homojunction　within　n-CIS/o-CIS　is　systematically　investigated　via　a　series　of　characterizations,　which　can　generate　an　internal　electric　field　to　facilitate　the　separation　and　migration　of　photogenerated　electron-hole　pairs.　The　2D/3D　n-CIS/o-CIS　composite　exhibits　significantly　improved　photocatalytic　activity　and　stability　in　the　selective　oxidation　of　phenylcarbinol　(PhCH2OH)　to　benzaldehyde　(PhCHO)　when　compared　to　pure　n-CIS　and　o-CIS　samples　under　visible　light　irradiation.　It　is　hoped　that　this　work　can　contribute　novel　insights　into　the　development　of　metal　sulfides　S-scheme　homojunction　photocatalysts　for　solar　energy　conversion.　©　2024　The　Authors.　Advanced　Science　published　by　Wiley-VCH　GmbH.