We present a facile one-pot approach to fabricate tough TiO 2 -rGO-PDMAA nanocomposite hydrogel. Both synchronous polymerization of N, N -dimethylacrylamide (DMAA) monomer and reduction of graphene oxide (GO) sheets into porous hydrogel network are triggered by TiO 2 nanoparticles under the UV irradiation. The reduction of GO is accompanied color changes of the hydrogel from light-brown to black. The interpenetrating double hydrogel network between PDMAA chains and rGO can be fabricated at a considerable GO content, at which the hydrogel exhibits tough mechanical strength, good swelling ratio and quick self-recovery character. Benefiting from the excellent carrier mobility and large surface area of the rGO, our hydrogel has an improved photo degradation performance for methylene blue, suggesting its potential application in the wastewater treatment.