Undoped, single phase barite BaCrO₄ photocatalyst for the degradation of methylene blue under visible light

Abstract

54-58The photoassisted degradation of a phenothiazine dye, methylene blue, has been examined in aqueous dispersions under visible irradiation at wavelengths greater than 400 nm with BaCrO4 and bare TiO2. Spectral changes during the photocatalytic degradation of methylene blue suggest that the de-methylation is an initiation process of photocatalysis reaction followed by ring opening and finally mineralisation into mineral acid and water. Comparative study shows that BaCrO4 is a better photocatalyst than bare TiO2 under visible light irradiation. COD analysis suggests that the degradation of methylene blue is due to photocatalysis and not due to any other reason. Catalytic poisoning is observed for both the photocatalysts.</b