The production of clean and renewable hydrogen through water splitting using photocatalysts has received much attention due to the increasing global energy crises. In this study, a high efficiency of the photocatalytic H(2) production was achieved using graphene nanosheets decorated with CdS clusters as visible-light-driven photocatalysts. The materials were prepared by a solvothermal method in which graphene oxide (GO) served as the support and cadmium acetate (Cd(Ac)(2)) as the CdS precursor. These nanosized composites reach a high H(2)-production rate of 1.12 mmol h(-1) (about 4.87 times higher than that of pure CdS nanoparticles) at graphene content of 1.0 wt % and Pt 0.5 wt % under visible-light irradiation and an apparent quantum efficiency (QE) of 22.5% at wavelength of 420 nm. This high photocatalytic H(2)-production activity is attributed predominantly to the presence of graphene, which serves as an electron collector and transporter to efficiently lengthen the lifetime of the photogenerated charge carriers from CdS nanoparticles. This work highlights the potential application of graphene-based materials in the field of energy conversion.

Visible light photocatalytic H(2) production through water splitting is of great importance for its potential application in converting solar energy into chemical energy. In this study, a novel visible-light-driven photocatalyst was designed based on photoinduced interfacial charge transfer (IFCT) through surface modification of ZnS porous nanosheets by CuS. CuS/ZnS porous nanosheet photocatalysts were prepared by a simple hydrothermal and cation exchange reaction between preformed ZnS(en)(0.5) nanosheets and Cu(NO(3))(2). Even without a Pt cocatalyst, the as-prepared CuS/ZnS porous nanosheets reach a high H(2)-production rate of 4147 μmol h(-1) g(-1) at CuS loading content of 2 mol % and an apparent quantum efficiency of 20% at 420 nm. This high visible light photocatalytic H(2)-production activity is due to the IFCT from the valence band of ZnS to CuS, which causes the reduction of partial CuS to Cu(2)S and thus enhances H(2)-production activity. This work not only shows a possibility for substituting low-cost CuS for noble metals in the photocatalytic H(2) production but also for the first time exhibits a facile method for enhancing H(2)-production activity by photoinduced IFCT.

Photocatalytic hydrogen (H 2 ) production from water splitting under visible-light irradiation is considered to be an attractive way to solve the increasing global energy crises in modern life. In this study, highly efficient photocatalytic H 2 production without the assistant of a cocatalyst was achieved using Zn1 1−x Cd x S solid solutions as the visible-light-driven photocatalysts and a mixed Na 2 S and Na 2 SO 3 aqueous solution as the sacrificial reagent. The Zn 1−x Cd x S samples were prepared by a simple zinc−cadmium− thiourea (Zn−Cd−Tu) complex thermolysis method using thiourea, zinc acetate (Zn(Ac) 2 ), and cadmium acetate (Cd(Ac) 2 ) as the precursors. The obtained Zn 1−x Cd x S solid solutions feature a small crystallite size and precisely controllable band structure, which are beneficial for the photocatalysis. When the Zn/Cd molar ratio is 1:1, the prepared Zn 0.5 Cd 0.5 S sample exhibits the highest H 2 -production rate of 7.42 mmol•h −1 •g −1 , exceeding that of the pure CdS and ZnS samples by more than 24 and 54 times, respectively, and even much higher than that of the optimal Pt-loaded CdS. This high photocatalytic H 2 -production activity is attributed predominantly to enough visible-light absorption capacity and suitable conduction band potential of the Zn 0.5 Cd 0.5 S solid solution, which is further evidenced from the related theory calculations on the band structures of the Zn 1−x Cd x S solid solutions. Moreover, the calculation on the Mulliken populations of Zn, Cd, and S atoms for the first time provides new insight into the deep understanding of the chemical shifts of element binding energies for the Zn 1−x Cd x S solid solutions and the designing of new ternary photocatalytic materials.