Photocatalytic decomposition of 4-t-octylphenol over NaBiO 3 driven by visible light: Catalytic kinetics and corrosion products characterization

Abstract

The photocatalytic decomposition of 4-t-octylphenol (4-t-OP) by NaBiO 3 photocatalyst and the catalyst stability in aqueous solution were investigated systematically for the first time. The results showed that some parameters such as catalyst dosage, initial 4-t-OP concentration and pH value of the solution had great effects on the photocatalytic activity. The NaBiO 3 photocatalyst maintained considerable catalytic performance under visible light (λ > 400 nm) irradiation and exhibited a higher photocatalytic activity compared to the commercialized photocatalyst P25. In addition, the corrosion products of NaBiO 3 catalyst under acid condition (HCl aqueous solution contained) were characterized by X-ray diffraction (XRD), transmittance electronic microscopy (TEM), selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS) and UV-vis transmittance spectrum analysis. The results showed that NaBiO 3 was unstable under the acidic condition and the catalyst could convert into Bi 3+-containing compounds such as Bi 2O 3, etc. The experiment demonstrates that NaBiO 3 can be corroded to nano-sized BiOCl crystal in the presence of hydrogen chloride, the band gap of which was estimated to be 3.28 eV by Tauc's approach. © 2009 Elsevier B.V. All rights reserved.