Most recently, much attention has been devoted to photocatalytic materials that may help to solve the global energy crisis and may provide environmental protection. Herein, novel cocatalysts based on few layered MoS2 and TiO2 nanomaterials have been designed by growing MoS2 nanosheets on the surface of TiO2 nanospheres through a facile hydrothermal method. The method allows the formation of TiO2/MoS2 core-shell heterostructures of uniform morphologies and stable structure and provides a good control over shell thickness. The mechanism that forms these heterostructures is discussed in detail. In addition, as cocatalyst, MoS2 nanosheets can enlarge the light harvesting window to include visible light and improve the photocatalytic ability of TiO2. Using Rhodamine B as the model, the resultant heterostructure is demonstrated to possess excellent and stable photocatalytic activity in the degradation of organic pollutants under visible light illumination. The TiO2/MoS2 heterostructures possess this catalytic activity due to their large surface area and their excellent interface for separating holes and electrons. Therefore, this novel heterostructure nanomaterials possess potential applications in water treatment, degradation of dye pollutants, and environmental cleaning.