AbstractIn this study, graphitic carbon nitride was used as a support for CuO/TiO2 nanocomposite and was used for the photodegradation of ketoprofen (KP) in various water qualities. The formation of the CuO/TiO2@GCN nanocomposites was proven using different characterization methods. PXRD and Raman analyses of TiO2 and CuO/TiO2 showed that the composite peaks shifted relative to those of TiO2, showing interactions between the two materials. The morphology of CuO/TiO2@GCN consisted of CuO/TiO2 nanoparticles on the surface of the mat‐like GCN. CuO/TiO2@GCN had a narrower band gap and its photoluminescence emission peak was lower than of TiO2. CuO/TiO2@GCN was found to be the best performing photocatalyst that could be used over 3 cycles without major loss in activity. Also, the material was shown to be able to photocatalyze KP in groundwater. The by‐products of the photodegradation were identified by LC–MS. The electrical energy consumed for this process was 2.66E5 kWh/m3. The superior photocatalytic efficiency of CuO/TiO2@GCN relative to TiO2 was attributed to the increased charged separation and that light of higher wavelength was harvested.