Multi-walled carbon nanotubes (MWCNTs) were treated with HNO3 and H2SO4 to obtain activated/functionalized multi-walled carbon nanotubes (A-MWCNTs). The functionalization increases the stability and dispersive properties of the A-MWCNTs. A-MWCNTs supported and unsupported bimetallic oxides nanoparticles were synthesized from their respective salts through chemical reduction method. Five different supported and unsupported bimetallic oxides nanoparticles (A-MWCNTs/Mn–Zn oxides and Mn-Zn oxides NPs), (A-MWCNTs/Fe-Mn oxides and Fe-Mn oxides NPs), (A-MWCNTs/Cu-Ti oxides and Cu-Ti oxides NPs), (A MWCNTs/Ag-Co oxides and Ag-Co oxides NPs) and (A-MWCNTs/Co-Ti oxides and Co-Ti oxides NPs) were prepared. The supported and unsupported bimetallic nanoparticles were characterized by various instrumental techniques like scanning electron microscopy (SEM), energy dispersive X-rays (EDX) and X-rays diffraction (XRD). The SEM images shows that bimetallic oxides nanoparticles are mostly in spherical form. It also shows that the supported bimetallic oxides NPs are mostly in dispersed form on the surface of A-MWCNTs while the unsupported bimetallic oxides NPs are in agglomerated form and hence have low surface area as compared to the supported bimetallic oxides NPs. The EDX spectra show the concerned composition of the prepared supported and unsupported bimetallic oxides NPs. The EDX spectra also revealed that bimetallic NPs are in their oxides form as confirmed from the presence of oxygen. The presence of oxygen also confirms the functionalization of the A-MWCNTs, as carboxyl functional group is introduced during the acid treatment. All the supported and unsupported bimetallic oxides NPs were used as photocatalysts for the degradation of different dyes under UV irradiation in aqueous medium. In the photodegradation study, A-MWCNTs/Mn– Zn oxides and Mn-Zn oxides NPs were used for the photodegradation of malachite green, A MWCNTs/Fe-Mn oxides and Fe-Mn oxides NPs for methylene blue, A-MWCNTs/Cu-Ti oxides and Cu-Ti oxides NPs for alizarin red, A-MWCNTs/Ag-Co oxides and Ag-Co oxides NPs for congo red and A-MWCNTs/Co-Ti oxides and Co-Ti oxides NPs for Rhodamine-B dye photodegradation. The photodegradation of all the dyes shows that the supported bimetallic oxides NPs caused more degradation of the dye compared to the unsupported bimetallic oxides NPs. This is due to the dispersion of the bimetallic NPs on the surface of A-MWCNTs. The effect of various parameters such as the irradiation time, catalyst dosage, dye concentration and pH of the medium on the photodegradation of dyes was studied. The catalytic efficiency of recycled photocatalysts was also evaluated for the same dye under the same experimental conditions, which showed less activity compared to the original photocatalysts.