Nitrogen-doped graphene/CdS hollow spheres nanocomposite with enhanced photocatalytic performance

A novel N-doped graphene/CdS hollow sphere nanocomposite photocatalyst was synthesized by a simple, template-free one-pot method. The samples were characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy, N sub(2) adsorption-desorption, photoluminescence spectroscopy, and X-ray photoelectron spectroscopy. Photocatalytic degradations of methylene blue and salicylic acid were carried out to evaluate the photocatalytic activity of the nanocomposites under visible light irradiation. The N-graphene/CdS nanocomposites exhibited excellent stability and high photocatalytic activity, exceeding those of graphene oxide/CdS hollow sphere nanocomposites and pure CdS hollow spheres. This excellent photocatalytic activity of the nanocomposite was due to N-graphene acting as an excellent electron acceptor and transporter, thus reducing charge carrier recombination. It was also found that [middot]OH acted as the main reactive species in the degradation of methylene blue under visible-light irradiation.