Ultrasound exfoliation of g-C3N4 with assistance of cadmium ions and synthesis of CdS/g-C3N4 ultrathin nanosheets with efficient photocatalytic activity

Cadmium-assisted ultrasound exfoliation was used to synthesize CdS/g-C3N4 ultrathin nanosheet catalysts with visible-light photocatalytic activity. The samples showed enhanced photocatalytic performance. Xray diffraction, transmission electron microscopy, ultraviolet-visible diffuse reflection spectroscopy, Fourier transform infrared spectroscopy, and photoluminescence spectroscopy confirmed the synthesized CdS/g-C3N4 ultrathin nanosheets. The photocurrent intensity and degradation of methyl orange (MO) of ultrathin CdS/g-C3N4 photocatalyst were 2 and 1.4 times higher than those of CdS/g-C3N4 nanocomposite obtained via ultrasound exfoliation without assistance of cadmium ion. These results were due to the well-matched band structure and close contact interfaces between the g-C3N4 nanosheets and CdS, which resulted in the effective transfer and separation of the photogenerated charge carriers. The mechanism for the photodegradation of MO by ultrathin CdSig-C3N4 photocatalyst was also investigated. (C) 2015 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.