• Copper oxide and Copper Cobaltite have been successfully synthesized using Co-precipitation method. • Both prepared oxides show efficient photocatalytic activity in the degradation of malachite green dye under solar or microwave irradiation. • Photocatalyst amount and dye concentration significantly affected the rate of MG photodegradation. Advanced Oxidation Processes (AOPs) have been developed in the field of environmental technologies. The aim of this study was to verify the efficiency of heterogeneous photocatalysis in the AOPs for the degradation of organic pollutants. The photocatalytic degradation processes were carried out under sunlight and microwave irradiation in remediation of malachite green (MG) dye taken as model organic pollutant. The copper oxide and copper-cobalt bimetallic oxide (Cu-500 and CuCo-500) were prepared by a simple coprecipitation method and calcined at 500 °C. The synthesized photocatalysts were characterized by X-ray diffraction (XRD), Fourier-Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy coupled with Energy Dispersive X-ray spectroscopy (SEM-EDX), and Diffuse Reflectance Spectroscopy (DRS) analysis for optical properties (band gap of 1.49 and 1.44 eV for Cu-500 and CuCo-500, respectively). Thereafter, the catalytic activities of the prepared photocatalysts for MG photodegradation were investigated. The influence of different parameters on the photocatalytic reactions, such as photocatalyst mass, initial dye concentration, and irradiation source, was studied. The results reveal the efficiency of the synthesized photocatalysts in the photodegradation of MG with higher rate and good reusability. Hence, the monometallic Cu-500 photocatalyst exhibited better catalytic performance compared to bimetallic CuCo-500.