Uses for Photocatalysis Tests
The current ISO standards for photocatalysis span five different test categories, reflecting the different applications, which are listed in the table below:
|Test Category||Test pollutant||ISO standard reference number||Suitable sample types and applications|
|Air Purification||NO||ISO 22197-1:2016||Exterior: NOx removing paint, concrete and tiles; Interior: odour-removing paint.|
|Water purification General||Methylene blue* Rz Ink Test||ISO 10678:2010 ISO 21066:2018||
Water purification units
General purpose test for non-porous smooth flat photocatalytic materials such as glass, paint, concrete, awning materials and tiles
|Self-cleaning||Contact angle/Oleic acid||ISO 27448:2009 ISO 19810: 2017||self-cleaning glass, concrete, tent/awning materials and tiles|
|Methylene blue*||ISO 10678:2010|
|Photosterilisation||Bacteria||ISO 27447:2009||Photo-induced sterile surfaces|
|Light Sources||n/a||ISO 10677:2011|
Semiconductor photocatalysis has many uses, such as: the photomineralisation of volatile and non-volatile organics and (to a lesser extent) inorganics, photoinduced superhydrophilicity and photosterilisation. In addition to its wide range of application, the process also benefits from having a few significant semiconductors, such as titanium oxide, that are extremely robust, both chemically and photochemically, and inexpensive. Therefore, a number of notable different commercial products have arisen from the wide-scale research conducted in this area.
These include: (i) self-cleaning glass, concrete, tent/awning materials and tiles, (ii) odour-removing paint for indoor applications, (iii) NOx removing paint, concrete and tiles for exterior applications, (iv) photo-induced sterile surfaces (ceramics and metals), (v) water and air purification units and (vi) defogging mirrors.
Accordingly, due to strong demand for test methods which enable correct evaluation of their performance, there are currently eight ISO standards, covering air and water purification, self-cleaning and antibacterial action, and light standards. These published standards address the need for the quantification of the activities of such semiconductor photocatalytic materials.