The CdS/C3N4 composites with efficient photocatalytic performance under visible light irradiation were synthesized by a facile sonochemical route. The as-prepared CdS/C3N4 composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high -resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance absorption spectra (DRS), fourier transform infrared spectroscopy (FTIR) and photoluminescence spectra (PL). The photocatalytic degradation of rhodamine B (RhB) by the CdS/C3N4 composites was explored and opt...