Evidence for the degradation of an emerging pollutant by a mechanism involving iso-energetic charge transfer under visible light

•Cu2O is the majority Cu-oxide present in sputtered ZnO/CuOx films.•XPS provided the proof for redox reactions during the Norfloxacin abatement.•Iso-energetic Cu2O/ZnO electron transfer leads to accelerated NFXdegradation.•A mechanism is suggested for the Norfloxacin degradation on ZnO/Cu2O films.