The present work describes the synthesis, characterization and photomineralization activity of synthesized Ce1-xZnxO2-x solid solution catalysts allowing the degradation of Diclofenac as a model of anti-inflammatory medicines in water. Oxygen deficient photocatalysts Ce1-xZnxO2-x (CeZnx), produced with mixing ZnO and CeO2 have been characterized for their crystallographic parameters, specific surface area and morphology. Photomineralization activity determinations using TOC analysis have shown efficient diclofenac photooxidation under sunlight. Moreover, results indicate that coexistence of Zn2+, Ce4+ and oxygen vacancies rate in CeZnx solid solution are key factors for strong drug mineralization. Finally, CeZn0.1 which is one of the photocatalysts synthesized in the present work represents a cheap and efficient reagent for organic matter photomineralization in wastewater.