Using Bismuth Vanadate/Copper Oxide Nanocomposite as Photoelectrochemical Sensor for Naproxen Determination in Sewage

Conventional sewage treatment plants are not usually designed to remove emerging contaminants, and this shortcoming leads to the discharge of pharmaceuticals, among other emerging pollutants, into the environment. The present work reports the development of BiVO4/CuO-based photoelectrochemical sensor for the determination of naproxen in sewage samples. Morphological characterizations were carried out by X-ray diffraction and Scanning electron microscopy. The band gap energy of the nanocomposite material was calculated by Tauc plots using the data obtained from diffuse reflectance spectroscopy analysis. The sensor presented analytical signal during the photocurrent generation simultaneously with the oxidation of naproxen on the working electrode. The sensor responses were found to be proportional to the increase in naproxen concentration in the linear range of 5 nmol L-1 to 480 nmol L-1, R-2=0.996, with a limit of detection of 5 nmol L-1. The presence of naproxen in sewage samples was successfully determined with recovery percentages above 95 %.