Photocatalytic degradation of caffeine using bismuth titanate under visible light

Abstract

Caffeine is ubiquitous in different environmental matrices, usually proposed as a tracer for human pollution since it can be entirely anthropogenic. Caffeine cannot be efficiently treated by simple near UV-Vis irradiation, the treatment of water polluted with emerging contaminants requires visible light active approach. Bismuth titanate with 12:1 has been prepared through simple alcohol assisted hydrothermal synthesis at different calcination temperature. The effect of calcination temperature on surface area and morphology and structure was analyzed by XRD, and TEM. Optical attributes were studied by PL and UV-Vis spectroscopy. During dark reactions, insignificant adsorption of 7.94% and 9% photolysis confirmed that degradation occurs in presence of photocatalyst under visible light. Parametric study including intensity of light, photocatalyst dose, pollutant concentration, pH was also investigated. While testing all prepared samples BIT-500⁰C showed 86% degradation at 0.3g/L in 20ppm solution in acidic condition i.e., pH=2.All the reaction followed pseudo-first-order kinetics. Mechanism of photocatalytic degradation has also been studied. This study provides to synthesized more efficient visible light active photocatalyst for the degradation of emerging contaminants in water bodies. Keywords: Bismuth titanate, calcination temperature, photocatalytic performance, Caffeine CAF.