Some oxide semiconductors with visible-light-driven photocatalysis such as Bi₂Fe₄O₉, CaBi₂O₄, Bi₆WO₁₂ become a hot topic. These oxides can be applied to the absorption of visible light for their relatively small bandgaps. Prof. XU Jinbao’s research group from Xinjiang Technical Institute of Physics & Chemistry, Chinese Academy of Sciences, explored the low-heating temperature solid state precursor method to synthesize Bi₂Fe₄O₉ submicron-rods. The diameter of Bi₂Fe₄O₉ submicron-rods is about 500-800 nm and the length of them is about 2-4 μm(Fig.1). 

 Researchers adopted precursor method to further calcine in low-heating temperature range from 600 to 800 °C to directly synthesize novel Bi₂Fe₄O₉ submicron-rods. It turns out that the Bi₂Fe₄O₉ submicron-rods attained at 700℃possess a perfect submicron-rod shape with a smaller bandgap (1.76 eV), which is smaller than the reported value of TiO₂ (3.2 eV)（Fig. 2）. Based on XRD and SEM result, the structure and morphology of the Bi₂Fe₄O₉ are closely related to reaction temperatures. Due to their good morphology and small bandgap, Bi₂Fe₄O₉ submicron-rods have the potential to be applied to visible-light-driven photocatalyst for environmental cleanup and optoelectric devices for solar energy conversion to electricity.

The work has been published on Journal of Alloys and Compounds (2013, 562, 64–68) and a related patent has been authorized (No.201110045937.7).

The related work was supported by the “Hundred Talents Project” Foundation and Western Light Talent Culture Project of CAS.