Utilizing　semiconductor　quantum　dots　(QDs)　to　construct　a　bifunctional　reaction　system　of　coupling　CO2　reduction　with　biomass　valorization　represents　an　appealing　approach　for　the　production　of　useable　fuels　and　value-added　chemicals.　Herein,　we　present　an　efficient　cooperative　photocatalytic　process　for　simultaneously　achieving　the　reduction　of　CO2　to　syngas　and　the　oxidation　of　biomass-derived　furfuryl　alcohol　to　furfural　and　hydrofuroin　over　SiO2-supported　CdSe/CdS　QDs　(CdSe/CdS-SiO2).　The　type-II　band　alignment　in　CdSe/CdS　core/shell　heterostructures　enables　effective　charge　separation　and　interfacial　charge　migration　concurrently.　By　further　assembly　onto　a　spherical　SiO2　support,　the　optimized　CdSe/CdS-SiO2　composite　exhibits　remarkably　enhanced　activities　for　syngas　and　furfural/hydrofuroin　production,　which　are　2.3　and　3.5　times　higher　than　those　of　binary　CdSe/CdS　core/shell　QDs,　and　90.4　and　18.5　times　higher　than　those　of　bare　CdSe　QDs,　along　with　good　stability.　In　particular,　by　altering　the　thickness　of　the　CdS　shell,　the　syngas　CO/H2　ratio　can　be　precisely　modulated　within　a　wide　range　(1.6　to　7.1),　which　serves　as　crucial　feedstock　for　the　production　of　liquid　fuels.　This　work　is　expected　to　develop　core/shell　QD-based　photocatalysts　for　versatile　and　available　photoredox-catalyzed　reaction　systems　that　integrate　CO2　valorization　with　biomass　upgrading.　©　2024　The　Royal　Society　of　Chemistry.