Titanium dioxide (TiO2) deposition on activated carbon (AC) is widely used for pollutant photodegradation. In this study, a simple and efficient method for preparing AC/TiO2 composites under microwave irradiation was developed for photocatalytic degradation of rhodamine B (RhB) under UV light. Results of X-ray diffraction, scanning electron microscopy, and transmission electron microscopy revealed that TiO2 nanoparticles are anatase and rutile, with a spherical shape and a particle size of 20-50 nm and are well distributed on the AC surface. The UV-vis spectrum of TiO2 coated on AC showed an evident red-shift and exhibited stronger optical absorption capacity than pure TiO2. The AC/TiO2 nanoparticles prepared at a microwave power of 700W for 15 min exhibited 98% efficiency in removing RhB dye under UV irradiation for 30 min. The high photocatalytic activity of AC/TiO2-700W could be mainly attributed to the high sorption capacity of the mesoporous carbon material and high TiO2 content, which could produce higher quantity of (OH)-O-center dot. This study provides a rapid synthesis technique to prepare AC/TiO2 and a novel method to improve photocatalytic efficiency via synergistic effect for other catalytic systems. (C) 2015 Elsevier B.V. All rights reserved.