Highly efficient Y and V co-doped ZnO photocatalyst with enhanced dye sensitized visible light photocatalytic activity

Abstract

A series of Y and V co-doped ZnO (YVZ) nanoparticles have been synthesized by surfactant assisted sol gel method with an aim to enhance the photocatalytic activity under visible light for degradation of organic pollutants. The prepared samples were characterized by standard analytical techniques such as XRD, XPS, SEM-EDX, TEM, UV–vis spectroscopy, FT-IR, BET, TGA and PL spectroscopy. The XRD analysis clarifies the coexistence of Y and V into ZnO as evidenced by the shift of plane towards the lower theta value. The photodegradation performances of the prepared samples were evaluated by studying the degradation of Rhodamine B (RhB), Methylene Blue (MB) and 4-nitrophenol (4-NP) under visible light irradiation. Among the series of synthesized YVZ nanoparticles, 3-YVZ (3%Y/1%V-ZnO) was found to be the most active photocatalyst for the degradation of organic pollutants under investigation. This remarkably improved photocatalytic activity of 3-YVZ could be attributed to the strong absorption of visible light and effective separation of photoinduced e−- h+ pair. The mineralization of RhB was investigated by measuring the COD depletion as a function of time. In addition, the influence of operational parameters such as, catalyst dosage and initial reaction pH was optimized with most active 3-YVZ photocatalyst for degradation of RhB as a function of time. The quenching experiments were conducted to determine the main reactive species formed in the reaction mixture and accordingly a mechanism for enhanced photocatalytic activity has been proposed.