2D Hybrid Nanostructure of Reduced Graphene Oxide–CdS Nanosheet for Enhanced Photocatalysis

Abstract

Graphene-based hybrid nanostructures have recently emerged as a new class of functional materials for light-energy conversion and storage. Here, we have synthesized reduced graphene oxide (RGO)-semiconductor composites to improve the efficiency of photocatalysis. Zero-dimensional CdS nanoparticles (0D), one-dimensional CdS nanorods (1D), and two-dimensional CdS nanosheets (2D) are grafted on the RGO sheet (2D) by a surface modification method using 4-aminothiophenol (4-ATP). Structural analysis confirms the attachment of CdS nanocrystals with RGO, and the strong electronic interaction is found in the case of a CdS nanosheet and RGO, which has an influence on photocatalytic properties. The degradation of dye under visible light varies with changing the dimension of nanocrystals, and the catalytic activity of the CdS NS/RGO composite is ∼4 times higher than that of CdS nanoparticle/RGO and 3.4 times higher than that of CdS nanorod/RGO composite samples. The catalytic activity of the CdS nanosheet/RGO composite is also found to be ∼2.5 times than that of pure CdS nanosheet samples. The unique 2D-2D nanoarchitecture would be effective to harvest photons from solar light and transport electrons to reaction sites with respect to other 0D-2D and 1D-2D hybrid systems. This observation can be extended to other graphene-based inorganic semiconductor composites, which can provide a valuable opportunity to explore novel hybrid materials with superior visible-light-induced catalytic activity.

Rapid Microwave‐Assisted Synthesis of CdS/Graphene/MoSx Tunable Heterojunctions and Their Application in Photocatalysis

“…In addition, due to the more positive potential of MoS x conduction band, the latter nanostructure may directly accept electrons from the CdS conduction band . As for the catalytic activity, both heteroatom‐doped graphene and MoS 2 components are expected to act as efficient catalytic sites for the photoreduction of 4‐nitrophenol …”

The Morphology–Property Effect and Synergetic Catalytic Effect of CdS as Electrocatalysts for Dye-Sensitized Solar Cells

“…No diffraction peaks for RGO can be observed in the CdS/RGO composites is due to that the main characteristic peak of RGO at about 25.0 • may be overlapped by the (100) peak of hexagonal CdS. 37,38 Scanning electron microscopy and transmission electron microscopy analysis.-The morphology and structure of the synthesized products have been investigated using SEM and TEM techniques. Figure 2a and 2e present overall SEM images of CdS nanoparticle/RGO and CdS nanorod/RGO, respectively, revealing the uniform sprinkle of nanoparticles and nanorods on graphene nanosheets.…”

Graphene in Photocatalysis: A Review

“…In 2011, Xiang et al first constructed graphene/TiO 2 with exposed (001) facets (as shown in Figure ) and graphene/g‐C 3 N 4 2D–2D composite photocatalysts, both of which exhibited significantly enhanced photocatalytic H 2 ‐evolution activities due to the efficient charge separation through 2D–2D coupling interfaces. Subsequently, a series of 2D semiconductor nanosheets/nanoplates (e.g., TiO 2 , CdS, Fe 2 O 3 , SnNb 2 O 6 , BiVO 4 , Bi 2 WO 6 , BiOBr, Cu doped SnS 2 , CoS, ZnIn 2 S 4 , In 2 S 3 layered double hydroxide, and AgBr) have been coupled with graphene nanosheets to fabricate various 2D–2D coupling photocatalyst systems for different applications. For example, Bera et al compared the photocatalytic activities of CdS nanoparticle/RGO, CdS nanorod/RGO, CdS nanosheet/RGO composites by changing the size and morphology of semiconductor nanomaterials (0D, 1D, or 2D) .…”