Robust Co₉S₈@CdIn₂S₄ Cage for Efficient Photocatalytic H₂ Evolution

We construct here a highly active and stable Co₉S₈@CdIn₂S₄ heterostructure for photocatalytic H₂ evolution under visible light. In a hierarchical hollow construction with closely connected heterogeneous shells, two photoactive sulfide semiconductors are incorporated rationally. This unique architecture can efficiently allow photoinduced charges to be separated and transferred and provide a broad surface area and exposure of rich sites for photocatalytic redox reactions. The Co₉S₈@CdIn₂S₄ hierarchical hollow heterostructure shows enhanced light-harvesting ability and remarkable catalytic activity because of its distinctive structural and compositional advantages. The photocatalyst shows a high hydrogen evolution rate of 4604 μmol h^–1 g^–1 without any noble metal as a cocatalyst under 1.5 AM simulated light irradiation. In this work, using the two-dimensional ultrathin subunits with distinct structural and compositional benefits, we show how this material can be interfaced successfully to give intriguing photophysical properties.