Hybrid 3-dimensional (3D) structures composed of zinc oxide (ZnO) nanorods and reduced grapheme oxide hydrogel (rGOH) were fabricated by chemical reaction between Zn ions and GO followed by in-situ lateral growth of ZnO nanorods using Zn ions as seed points. The 3D networked ZnO nanorod rGOH (ZNR-GOH) fabricated in this study exhibited excellent methylene blue (MB) removal efficiency due to efficient physical adsorption of dye molecules because of electrostatic attractive forces and enhanced photocatalytic activity by the laterally grown ZnO nanorods. The Langmuir Hinshelwood rate constant of ZNR-GOH was 4-fold higher than that of pristine rGO due to the enhanced photocatalytic effects obtained by incorporating laterally grown ZnO nanorods inside the rGOH network. (c) 2014 Elsevier Inc. All rights reserved.