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Technology Transfer from the University of Oxford

VISIBLE LIGHT PHOTOCATALYST - Isis Project No 2241

A new production method gives photocatalysts with high activity to visible light. The materials have applications in water and air purification, anti-soiling for building materials and anti-bacterial properties.

Marketing Opportunity

Photocatalysts take energy from visible light or ultraviolet (UV) irradiation and use that energy to speed up chemical reactions. The market for photocatalysts is growing rapidly and photocatalysts have a number of uses, including:

  • building materials – for example, self-cleaning glass and concrete;
  • water treatment – decolourising waste water, and removal of water contaminants;
  • air purification – removing harmful gases such as carbon monoxide and ammonia;
  • deodorising – destruction of volatile organic compounds; and
  • disinfection – prevention of bacterial and mould growth.

The Oxford Invention

Currently the market leading photocatalysts are based on titanium dioxide. However, this is normally of low surface area, which limits its catalytic activity. Furthermore, it can only absorb UV light, and as UV light is only 5% of solar light, the efficiency of titanium dioxide photocatalysts is very limited.

Oxford researchers have now developed a method for preparing titanium oxynitrides, which gives high surface area photocatalysts that strongly absorb visible light. This improves the energy efficiency of the photocatalysis 6-fold by comparison with UV-only catalysts.  Furthermore, the method allows excellent control of the catalyst composition and structure and gives catalysts with very high surface area and excellent activity.

Transmission Electron Microscopy (TEM) image of the Oxford photocatalyst, showing detail of catalyst particles on sub-nanometer scale.

For example, the dye methyl blue was decoloured in just 30 minutes using the Oxford photocatalyst, whereas a leading, commercially available photocatalyst took over 5 hours to achieve the same result.

Patent Status                                                                                                           

This work is the subject of a patent application, and Isis would like to talk to companies interested in developing the commercial opportunity that this represents. Please contact the Isis Project Manager to discuss this further.

Request Further Information: Project Number 2241 Visible Light Photocatalyst