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.　The　2D/3D　CdIn2S4　S-scheme　homojunction　photocatalysts　are　reported　for　the　first　time　through　the　straightforward　adjustment　of　PVP　amount,　which　generates　an　internal　electric　field　to　facilitate　the　separation　and　migration　of　photogenerated　charge　carriers,　thus　significantly　improving　the　photocatalytic　activity　and　stability　of　the　selective　oxidation　of　phenylcarbinol　to　benzaldehyde.　image