Coupling　hydrogen　production　with　selective　organic　synthesis　in　one　cooperative　manner　offers　a　novel　strategy　for　green　synthesis　by　virtue　of　the　photogenerated　carriers.　Herein,　a　dual-functional　photocatalyst　of　CoSx/Cd0.7Zn0.3S　without　noble　metals　is　reported　for　efficient　selective　benzaldehyde　(BAD)　synthesis　coupled　with　H2　production.　The　CoSx/Cd0.7Zn0.3S　composite　showed　a　higher　photocatalytic　performance　than　Cd0.7Zn0.3S　and　1　wt%　Pt/Cd0.7Zn0.3S,　which　was　attributed　to　the　loaded　CoSx,　as　the　cocatalyst,　which　could　accumulate　the　photogenerated　electrons　from　Cd0.7Zn0.3S,　promote　the　separation　of　photogenerated　charge　carriers,　and　reduce　the　overpotential　of　hydrogen　production.　This　study　provides　a　new　strategy　for　the　design　and　synthesis　of　low-cost,　high-efficiency　composite　materials　for　photocatalytic　efficient　selective　benzaldehyde　(BAD)　synthesis　coupled　with　H2　production.　©　2023　The　Royal　Society　of　Chemistry.