Unmodified and Ag modified Bi4Ti3O12:Ag(x%) (x=2 and 5) nanoparticles have been synthesized sonochemically and characterized using X-ray diffraction, X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) surface area analysis, scanning electron microscopy (SEM), energy dispersion X-ray spectrum (EDS) analysis, transmission electron microscopy (TEM) and UV-vis diffuse reflectance spectroscopy. In the presence of unmodified Bi4Ti3O12 nanoparticles, complete photocatalytic degradation of Rhodamine B (RhB) was observed under UV light within 45 min. However, the response of this material for photodegradation of RhB under visible light was poor and could be greatly enhanced with Ag modification. A possible mechanism for this observation has been discussed in detail. The reusability of the material has also been tested and it has been found to have favorable recycling capability. Moreover, the Ag- modified Bi4Ti3O12 has been tested for RhB degradation from a wastewater sample under sunlight and promising results have been obtained. (C) 2015 Elsevier Ltd. All rights reserved.