Abstract

Bismuth oxides (Bi<inf>2</inf> O<inf>3</inf>) are of interest because of their suitable band gaps for photocatalytic activity. Herein, α-Bi<inf>2</inf>O<inf>3</inf> microrods were synthesized by a facile chemical method, and were characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), scanning electron microscope (SEM), and UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS). The results showed that the particles were rod-shaped with lengths in the range of 5-10 μm. Crystalline structure of the particles was monoclinic, and the band gap was around 2.88 eV. When citric acid was used in the synthesis, the bismuth oxide microrods can self-assemble into the hierarchical flower-like structures leading to the alteration of band gap. This self-assembled α-Bi<inf>2</inf> O<inf>3</inf> microstructure can be employed as a photocatalyst with alterable band gap.