Characterization and photocatalytic activity of Cu-doped K2Nb4O11

✍ Scribed by Gaoke Zhang; Xi Zou; Jie Gong; Fangsheng He; Hao Zhang; Shixi Ouyang; Hanxing Liu; Qiang Zhang; Ying Liu; Xia Yang; Bo Hu

• Book ID: 104057044
• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 506 KB
• Volume: 255
• Category: Article
• ISSN: 1381-1169
• DOI: 10.1016/j.molcata.2006.03.073

✦ Synopsis

The Cu-doped tungsten bronze (TB) type potassium niobate K 2 Nb 4 O 11 was synthesized by solid-state reaction method in air. The crystal structure and morphology of the prepared samples were confirmed by X-ray diffraction analysis and scanning electron microscope. The photocatalytic activity of the prepared samples was evaluated using acid red G as a model organic compound and the photocatalytic reaction belongs to the first order kinetics. The results show that Cu-doping significantly increased the photocatalytic activity of K 2 Nb 4 O 11 catalyst when the concentration of Cudoped was lower, but the photocatalytic activity of the catalyst was decreased when the concentration of Cu-doped was higher. Although the surface areas of the 0.2 wt.% Cu-doped K 2 Nb 4 O 11 and the 0.5 wt.% Cu-doped K 2 Nb 4 O 11 are very lower, the photocatalytic activities of these compounds are close to that of TiO 2 -P25. Copper doping is good for the compounds to form tetragonal TB structure and improving the crystallinity of the compounds. The diffuse reflectance spectrum of Cu-doped K 2 Nb 4 O 11 showed a red shift. X-ray photoelectron spectroscopy analysis confirmed that the niobium with mixed valence state exists in the crystal structure of the compound K 2 Nb 4 O 11 . The effects of the Cu-doped and the mixed valence state of niobium on the photocatalytic activity of the catalyst were discussed.