Thin bismuth oxide films prepared through the sol–gel method as photocatalyst

In this paper, thin bismuth oxide films were prepared by the sol–gel method. The films were annealed at different temperatures, and then applied to degrade a kind of typical textile industry pollutant (Rhodamine B), respectively, in order to study the influence of bismuth oxide crystal phases on their photocatalytic properties. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) techniques and a surface profiler were applied to characterize the thin films annealed at different temperatures. The results show that different annealed temperatures cause the transformation between monoclinic phase and tetragonal phase of bismuth oxides and bismuth oxide films annealed at 550 °C contain a higher proportion of the tetragonal phase of bismuth oxides than those annealed at other temperatures, which leads to higher electronic binding energy and photocatalytic properties for these oxides in the films.

Graphical abstractBismuth oxide films are prepared through the sol–gel method and the photocatalytic properties of bismuth oxide films annealed at different temperatures are studied in the paper. It has been found that the bismuth oxide films annealed at 550 °C have the best photocatalytic properties of all due to the transformation of bismuth oxide phases. Figure optionsDownload full-size imageDownload as PowerPoint slide