In the current study, ZnO, CuO and ZnO/CuO mixed metal oxide nano-composites with different molar ratio of Zn/Cu (10:1, 8:1, 6:1, 4:1, 2:1) were prepared via low temperature hydrothermal synthesis technique. The consequences of different synthesis conditions such as molar ratio, pH and processing temperature on physicochemical properties of ZnO/CuO nano-composites were also studied. The surface morphology, elemental composition, crystal structure, chemical states and optical characteristics of the prepared nano-composite materials were determined using various techniques such as field emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDX), X-ray diffraction analysis (XRD), X-ray photo-electron spectroscopy (XPS) and UV-visible diffused reflectance spectra (UVDRS). A morphological change in bitter gourd structured ZnO as well as improved optical response of ZnO after incorporation of CuO was observed. The decreased recombination rate of charge carriers, effectual generation of photoinduced charge carriers, formation of hetero-junction system and unique morphology are the responsible factors for improved photodegradation characteristics of prepared ZnO/CuO nanocomposites. Role of active species and pH of dye solution in degradation process was also studied. (C) 2020 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.