Microwave-assisted synthesis and interfacial features of CdS/kaolinite nanocomposite

Sphere-like cadmium sulfide (CdS) nanoparticles were uniformly assembled on kaolinite to synthesize CdS/kaolinite nanocomposite via a microwave irradiation process in aqueous solution with the assistance of polyvinylpyrrolidone (PVP). Cadmium ions were incorporated into the surface of kaolinite and hydrophilic PVP, and reacted with an introduced sulfur source under a microwave field to obtain the CdS/kaolinite nanocomposite. Meanwhile, the hydrogen bonds formed between hydroxyl groups of kaolinite and N atom in the pyrrolidone-ring of PVP. Therefore, CdS nanoparticles could be easily assembled on kaolinite rods by using this process, the addition of PVP was beneficial to the well deposition of CdS nanoparticles on kaolinite rods, while the diameter of CdS nanoparticles could be controlled via adjusting the experimental parameters. The as-synthesized CdS/kaolinite nanocomposite showed better luminescence properties than pure CdS nanoparticles, indicating its potential applications in the optoelectronic fields. Atomic-level interfacial interaction between the CdS nanoparticles and the kaolinite surfaces was depicted, and a mechanism for assembling CdS nanoparticles on kaolinite rods was in detail discussed.