Bismuth Tungstate Thin Film Electrode

The overuse of fossil fuels has resulted in the continuous rise of global temperature. Finding new clean energy has become imminent. In the existing emerging energy sources, solar energy has attracted much attention as an inexhaustible and pollution-free energy. Recently, there have been reports from foreign countries that a scientific research team has successfully implemented water hydrogen by using photocatalysis.

Bismuth tungstate (Bi₂WO₆) is a semiconductor material with indirect band gap transition. It has a narrow forbidden band width (2.75-2.9eV). The wavelength of absorption light can extend to the visible region (450nm), and has good chemical stability. Compared with tungsten trioxide (WO₃), the valence band position closer to the reduction potential of hydrogen, water decomposition reaction can be carried out at lower bias.

There are two commonly used methods for preparing bismuth tungstate film electrode materials: sol-gel method and ion exchange method. The Bi₂WO₆ film method based on the sol-gel method can use less template and the film has a single appearance. The ion exchange method has been widely used in the preparation of Bi₂WO₆ film electrode materials because of its low equipment requirements, simple operation and mild reaction conditions. However, ion exchange method using WO₃ as precursor has higher ion exchange temperature and longer exchange time. Meanwhile, a layer of WO₃ between Bi₂WO₆ film and tungsten substrate is not conducive to the conduction of electrons.

Researchers have an innovative Bi₂WO₆ nano thin film with photocatalytic properties, including Bi₂WO₆ nanometer thin film layer growth consists of Bi₂WO₆ nanostructures on a substrate, the substrate for fluorine doped tin oxide (FTO) conductive glass, Bi₂WO₆ nanosheets grown perpendicular to the substrate FTO conductive glass. The Bi₂WO₆ nanomaterials prepared by this method have a large surface area of one-dimensional nanosheets, and provide direct and smooth transmission paths for photoelectrons and holes, which can effectively promote the electron transport to the material interface.

Compared with other semiconductor materials, the redox reaction of water can take place in relatively low current intensity and low overpotential. It has excellent photoelectrochemical performance and high industrial value.

• < Prev
• Next >