In this work, molybdenum disulfide-graphene oxide (MoS2-GO) composite hydrogel was prepared via a one-step hydrothermal method. The morphology and structure of the as-prepared hydrogels with different proportions of MoS2 and GO were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, electrochemical impedance spectra and UV-vis absorption spectroscopy. The photocatalytic performance of MoS2-GO nanocomposites was studied toward the degradation of methylene blue (MB). Results showed that the MoS2-GO nanocomposites exhibited improved photocatalytic activities in the degradation of MB with a maximum degradation rate of 99% under solar lights irradiation within 60 min. The synthesized MoS2-GO composite hydrogel possesses great potential toward the development of newly synthesizable catalysts in the field of organic degradation in water. (C) 2015 Elsevier B.V. All rights reserved.