Visible-light photocatalytic activity of the metastable Bi20TiO32 synthesized by a high-temperature quenching method

Metastable Bi20TiO32 samples were synthesized by a high-temperature quenching method using α-Bi2O3 and anatase TiO2 as raw materials. The photocatalytic activity of the as-prepared samples was measured with the photodegradation of methyl orange at room temperature under visible light irradiation. The Bi20TiO32 samples exhibited good absorption in the visible light region with a band gap of about 2.38 eV and the band structure of Bi20TiO32 was studied. Photodegradation against methyl orange was much better than α-Bi2O3 prepared by the same way. The photocatalytic activity of Bi20TiO32 samples is supposed to be associated with the hybridized Bi 6s and O 2p orbitals. In addition, the dispersive characteristic of Bi 6s orbital in the hybridized valence band facilitates the mobility of the photogenerated carriers and hampers their recombination.

Graphical abstractMetastable Bi20TiO32 samples were successfully synthesized by a quenching process. Photodegradation against methyl orange showed high visible-light activity and it was supposed to be associated with its corresponding band structure.Figure optionsDownload full-size imageDownload as PowerPoint slide