UV Induced Photocatalytic Degradation of Caffeine Using TiO2–H-Beta Zeolite Composite

Abstract

An anatase phase of the TiO2-H-beta (THB) zeolite composite photocatalyst is used for the photocatalytic degradation of caffeine, a persistent organic pollutant (POP). It is synthesized by a simple two-step sol-gel method. Phase formation, morphology, bandgap, and photocatalytic properties were analyzed using powder X-ray diffraction, scanning electron microscopy, and UV-Vis diffuse reflectance spectroscopy, respectively. The THB and the anatase TiO2 samples were then tested for the photocatalytic activity of the degradation of caffeine. Photocatalytic studies reveal that the as-prepared THB composite showed excellent activity for the degradation of 10 ppm caffeine solution. The chemical oxygen demand (COD) analysis found caffeine to have degraded with an efficiency of 96%. Scavenging experiments indicated that the hydroxide radical played an important role in the degradation of caffeine. The results highlight the role of the H-beta zeolite as an effective support to TiO2 and improved the photocatalytic activity. The study demonstrates that the THB composite could be effectively applied for the photocatalytic degradation of other POPs largely present in active pharmaceutical ingredients.