Photocatalytic decomposition of 4-t-octylphenol over NaBiO3 driven by visible light: Catalytic kinetics and corrosion products characterization

The photocatalytic decomposition of 4-t-octylphenol (4-t-OP) by NaBiO3 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 NaBiO3 photocatalyst maintained considerable catalytic performance under visible light (lambda > 400 nm) irradiation and exhibited a higher photocatalytic activity compared to the commercialized photocatalyst P25. In addition, the corrosion products of NaBiO3 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 NaBiO3 was unstable under the acidic condition and the catalyst could convert into Bi3+-containing compounds such as Bi2O3, etc. The experiment demonstrates that NaBiO3 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. (C) 2009 Elsevier BY. All rights reserved.