Photocatalytic Degradation of Rhodamine B with H₃PW₁₂O₄₀/SiO₂Sensitized by H₂O₂

Abstract

In order to remove aquatic organic dye contaminants by utilizing the inexpensive and inexhaustible solar energy, the Keggin-type H 3 PW 12 O 40 was loaded on the surface of SiO 2 with the sol-gel method and sensitized by H 2 O 2 solution. The photocatalytic degradation of rhodamine B (RhB) by H 3 PW 12 O 40 /SiO 2 (x) under simulated natural light irradiation was investigated. The effects of the initial RhB concentration, the solution pH, and catalyst dosage on the photocatalytic degradation rate of RhB were also studied. The results demonstrated that at optimal condition (initial concentration of methyl orange is 10 mg/L, catalyst dosage is 0.8 g, and the pH is 2.5) the degradation rate of RhB is as high as 97.7% after 2 h under simulated natural light irradiation. The reaction of photocatalysis for RhB can be expressed as a first-order kinetic model.