Our Visible Light Photocatalysts can purify water in two ways:

Mixed in powder form with the contaminated water, and stirred in a transparent vessel while iluminated with the ultraviolet in sunlight or artificial ultraviolet sources. When the water is purified, the photocatalyst is filtered out for re-use.  While there is an energy cost to the step of separating the clean water and the photocatalyst, the simplicity of the method and apparatus, as well as the high surface area contact between the photocatalyst and the contaminants, are advantageous.

Fixed to a filter material or surface in a tranparent window of a container, and illuminated.  Here the advantage is that there is no need to reclaim the photocatalyst from the clean water, but there is a loss of surface area because a good portion of the photocatalytic particles are in contact with a binder. Also, there can be some energy required to flow the contaminated water through the illuminated filter.

Nanoptek’s visible light photocatalyst powder can be used in either system.  Our particle size is larger than the industry-leading titania photocatalyst, which makes it easier to filter out, and much of it can even be settled out of the water in a relatively short amount of time.  And in spite of the reduced surface area of our larger particles, we are 24X more effective than the industry-leading titania photocatalyst in dye degradation tests. 

The same system hardware developed for our solar hydrogen generation photocatalyst, namely the flat panel SHG300 and the concentrating solar hydrogen generators (CSHGs), can also be used with our visible light photocatalysts with minor modification.   Our visible light photocatalysts can also be used with existing systems made by other companies.