Photoreduction of [PtCl6](2-) over hexagonal ZnIn2S4 led to the formation of surface deposited small PtS nanoparticles with a size of ca. 3 nm. The resultant PtS/ZnIn2S4 nanocomposites were fully characterized and their performance for photocatalytic splitting of thiols to produce disulfides and hydrogen was investigated. It was found that PtS significantly promoted the photocatalytic performance for thiols splitting to produce disulfides and quantitative hydrogen over ZnIn2S4 under visible light and no over-oxidized products of thiols were produced. An optimum performance was observed over 0.5 wt% PtS/ZnIn2S4, with a complete transformation of thiols to disulfides in 6 h. PtS/ZnIn2S4 nanocomposite is stable during the photocatalytic reaction and can be easily separated for recycling. The photocatalytic thiols splitting over PtS/ZnIn2S4 is an efficient and cost effective strategy to produce disulfides, which exhibits 100% atom economy since hydrogen is generated concomitantly. This study demonstrates that the coupling of water reduction with organics oxidation over semiconductor-based photocatalysts may find great potentials in organic syntheses.