摘要： The scheelite BaWO4 elaborated by co-precipitation, is a wide band gap semiconductor crystallizing in the tetragonal symmetry. The oxide is identi?ed by X-ray di?raction and characterized by scanning electron microscopy and di?use re?ectance. The optical transition (2.95 eV) involves O2-: 2p orbital and W6+ eg: level, further direct transition occurs at 4.88 eV. The peaks in the Raman spectrum are assigned to symmetrical vibrations of tetragonal units [WO4]2-. The oxide shows an oxygen de?ciency and the conductivity follows a thermally activated hopping of lattice polaron with activation energy of 0.31 eV. The photo electrochemical analysis of BaWO4 at pH 5.5 gives a ?at band potential of 0.20 VSCE and electrons density of 1.8 × 1019 cm?3. The positive slope of the plot (capacitance?2 - potential) indicates n type conduction, a result con?rmed by chrono-amperometry. The frequency dispersion of the real/imaginary impedances is undertaken both in the dark and under illumination; the response is modeled by an equivalent circuit with a predominant bulk contribution. As application, the photo electrons in the conduction band (?0.11 VSCE) reduce oxygen into radicals O2?, allowing a partial mineralization of ibuprofen, one of the most consumed medicaments. The electro-photocatalysis i.e. combined electrocatalysis/electro-photocatalysis using TiPt as cathode and BaWO4 as anode (100 mA/25 V) shows a high conversion yield (75%), in aerated ibuprofen solution (20 ppm) in less than 6 h under UV light (12 mW cm?2). The reaction follows a pseudo-?rst order kinetic with a rate constant of 3.7 × 10?3 min?1, about twice higher than that obtained by electrocatalysis (50%, k = 1.9 × 10?3 min?1).