Synthesis of CdS with Graphene by CBD(Chemical Bath Deposition) Method and Its Photocatalytic Activity

Synthesis of RGO (reduced graphene oxide)-CdS composite material was performed through CBD (chemical bath deposition) method in which graphene oxide served as the support and Cadmium Sulfate Hydrate as the starting material. Graphene-based semiconductor photocatalysts have attracted extensive attention due to their usefulness for environmental and energy applications. The band gap (2.4 eV) of CdS corresponds well with the spectrum of sunlight because the crystalline phase, size, morphology, specic surface area and defects, etc., of CdS can affect its photocatalytic activity. The specific surface structure (morphology) of the photocatalyst can be effective for the suppression of recombination between photogenerated electrons and holes. Graphene (GN) has unique properties such as a high value of Young's modulus, large theoretical specific surface area, excellent thermal conductivity, high mobility of charge carriers, and good optical transmittance. These excellent properties make GN an ideal building block in nanocomposites. It can act as an excellent electron-acceptor/transport material. Therefore, the morphology, structural characterization and crystal structure were observed using various analytical tools, such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. From this analysis, it is shown that CdS particles were well dispersed uniformly in the RGO sheet. Furthermore, the photocatalytic property of the resulting RGO-CdS composite is also discussed in relation to environmental applications such as the photocatalytic degradation of pollutants. It was found that the prepared RGO-CdS nanocomposites exhibited enhanced photocatalytic activity as compared with that of CdS nanoparticles. Therefore, better efficiency of photodegradation was found for water purification applications using RGO-CdS composite.