Rectorite was composited with BiOI to extend its applicability as an applied material with high adsorptive capacity and photocatalytic activity. The facile synthesis process involved ultrasonic irradiation and in situ reaction. The physicochemical properties of the as-prepared samples were characterized by means of X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), N 2 adsorption-desorption isotherms, and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). Rhodamine B (RhB), a typical organic contaminant, was used as the model contaminant to evaluate the adsorption capacity and photocatalytic performance of the prepared BiOI-rectorite composite. The adsorption process was found to obey pseudo-second-order kinetics. The equilibrium adsorption was well-modeled using the Freundlich adsorption isotherm. High photocatalytic activity under visible light irradiation was observed.