The demand for reactive dyes in industries has increased rapidly in recent years, and producing a large quantity of dye-containing effluent waste contaminates soils and water streams. Current efforts to remove these harmful dyes have focused on utilizing functionalized nanomaterials. A 3D polyurethane foam loaded with reduced graphene oxide (rGO) and ZnO nanocomposite (PUF/rGO/ZnO) has been proposed as an efficient structural design for dye degradation under the influence of visible light. The proposed structure was synthesized using a hydrothermal route followed by microwave irradiation. The resultant 3D PUF/rGO/ZnO was examined and characterized by various techniques such as XRD, FTIR, SEM, EDAX, BET, and UV–visible spectroscopy. SEM data illustrated that a good dispersion and embedment of the rGO/ZnO NPs within the PUF matrix occurred. The adsorption capacity for neat PUF showed that around 20% of the Methylene blue (MB) dye was only adsorbed on its surface. However, it was found that an exceptional adsorption capacity for MB degradation was observed when the rGO/ZnO NPs inserted into the PUF, which initially deteriorated to ~ 70 % of its initial concentration. Notably, the MB dye was completely degraded within 3 h.