By this work, we discussed about the influence of the graphene on the structural, optical and phonon properties of the CuO nanostructures. The observed variations in the morphology, crystallite size and band gap of the CuO nanostructures with respect to the loading amount of graphene were discussed. The observed broad optical absorption of the CuO nanostructures was explained with the help of the Mie scattering and Gan's theoretical approximations. The observation of the multiphonon activity related bands in the Fourier transform infrared spectroscopy (FTIR) and the Raman studies of the composites were discussed. The appearance of the surface enhanced Raman scattering (SERS) like enhancement in the Raman bands of the graphene in the composites was discussed by considering the surface plasmon resonance (SPR) of CuO nanostructures. The comparative study of the prepared composites for the treatment of dye effluent was discussed.