Graphene-based ternary composite photocatalysts with genuine heterostructure constituents have attracted extensive attention in photocatalytic hydrogen evolution. Here we report a new graphene-based ternary composite consisting of CdS nanorods grown on hierarchical layered WS2 /graphene hybrid (WG) as a high-performance photocatalyst for hydrogen evolution under visible light irradiation. The optimal content of layered WG as a co-catalyst in the ternary CdS/WS2 /graphene composites was found to be 4.2 wt %, giving a visible light photocatalytic H2 -production rate of 1842 μmol h(-1)  g(-1) with an apparent quantum efficiency of 21.2 % at 420 nm. This high photocatalytic H2 -production activity is due to the deposition of CdS nanorods on layered WS2 /graphene sheets, which can efficiently suppress charge recombination, improve interfacial charge transfer, and provide reduction active sites. The proposed mechanism for the enhanced photocatalytic activity of CdS nanorods modified with hierarchical layered WG was further confirmed by transient photocurrent response. This work shows that a noble-metal-free hierarchical layered WS2 /graphene nanosheets hybrid can be used as an effective co-catalyst for photocatalytic water splitting.

The excellent photocatalytic H2 production activity of Co3O4–CdS nanocomposite was mainly attributed to the formation of p–n heterojunctions between the p-type Co3O4 nanoclusters and n-type CdS nanorods, which could promote the photoinduced charge transfer and separation.

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CdS/CuS nano-heterojunction composites were synthesized by the solid-state strategy and exhibited the enhanced visible-light photocatalytic H2-evolution activity.

The ternary reduced graphene oxide (rGO)/g‐C3N4/Ag‐AgCl composite photocatalysts were prepared by a combined deposition‐precipitation and in situ photoreduction method. The prepared ternary graphene‐semiconductor‐metal nanocomposite photocatalysts exhibit controlled photocatalytic selectivity and high photocatalytic activity for the degradation of methylene blue (MB) and methyl orange (MO) solution under visible‐light irradiation. Significantly, the controlled photocatalytic selectivity of rGO/g‐C3N4/Ag‐AgCl (GCA) composites towards MO and MB can be modulated by the introduction or elimination of Ag‐AgCl and/or rGO sheets for tuning their surface charges and adsorption properties. In addition, the photocatalytic activity of GCA sample was indeed improved due to the efficient separation of photo‐generated carriers in the GCA composite, which could be attributed to the suitable band gap structure of g‐C3N4/Ag‐AgCl (CA) and the well electronic mobility of rGO sheets. The proposed mechanism for the controlled visible‐light photocatalytic selectivity and the enhanced photocatalytic activity of GCA composite was further confirmed by the trapping experiments, PL spectroscopy and transient photoelectric current response. This work may provide a new practical insight into the fabrication of innovative photocatalysts with the controlled selectivity and enhanced photocatalytic activity for environmental purification, clear energy production and solar energy conversion.