Titanium dioxide/cadmium sulfide photoanode applied to photoelectrodegradation of naproxen in wastewater

Abstract

• The application of photoelectrochemical method increased the catalytic response. • Photosensitization contributed to avoid recombination of e − /h + charges. • The EC involved is relatively inexpensive for removing 1.0 kg of NPX using the PEC method. In this work TiO 2 and CdS were synthesized, characterized, and applied on the fabrication of photoanodes for degradation of naproxen in aqueous matrices. The photoanodes were based on the deposition of the TiO 2 film over fluorine-doped tin oxide glass plates followed by a CdS electrodeposition film. Characterizations of the photoanodes were performed by linear sweep voltammetry, transmission electronic microscopy, energy-dispersive X-ray spectroscopy, and diffuse reflectance spectroscopy. The degradation process of naproxen was evaluated using UV–vis spectroscopy and total organic carbon. The CdS presented a low energy band gap, resulting in the increase of the photocurrent generated in the photoanode. The proposed photoanode showed efficiency for the photoelectrochemical degradation of naproxen with kinetic constant estimated at k = 1.1 × 10 −2 min −1 and t 1/2 = 62.2 min −1 .