Fabrication of mesh-like bismuth oxide single crystalline nanoflakes and their visible light photocatalytic activity

Mesh-like bismuth oxide single crystalline nanoflakes were synthesized via a bismuth oxalate precursor way. During the synthesis procedure bismuth oxalate precipitate was hydrothermally treated, and variation of the pH value of synthesis solution as well as the addition of L-lysine could effectively tune the crystal phase and morphology of the bismuth oxalate precursor. Depending on the crystalline phase of the precursors and the calcination temperature, monoclinic beta-Bi2O3 and tetragonal beta-Bi2O3 were selectively obtained. Optical properties of the Bi2O3 materials were investigated by UV-vis absorption and the results proved that bismuth oxides were visible light responsive. Photodegradation of rhodamine B was used as a model reaction to test the photocatalytic activity of the Bi2O3 samples. The photocatalytic activity of bismuth oxides was related to its crystalline phase and morphology. (C) 2010 Elsevier B.V. All rights reserved.