The foundational key to the puzzle is this: light affects matter. You already knew that. We are all aware that the light of the sun affects us and everything around us. Light energy, in the form of photons, activates chemical reactions in a range of scenarios.
We can be talking about visible light from the sun and light from other sources, such as LED or neon light, or we can be talking about light that we cannot perceive with our eyes. Light across the spectrum affects matter in different ways.
Infrared light, for example, causes molecules to vibrate and bend, which results in an increase in temperature or changed channels on your television.
Ultraviolet light both helps and harms living cells. When the sun's ultraviolet B (UVB) rays hit cholesterol in our skin cells, it provides the energy for our cells to synthesize Vitamin D. When ultraviolet A (UVA) rays penetrate deep into the skin, cell damage can occur. Good and bad, but the point is that there are chemical processes at play in response to the interaction with light energy.
The most familiar example may be the process of photosynthesis that we all studied in school – in response to visible light the plant grows by absorbing carbon dioxide and releasing oxygen.
Light affecting matter. Light affecting life!
To Titaron, and titanium dioxide.
Yes, light is a form of energy. This energy can be harnessed in different ways. Yet another example is found in solar cells that have the ability to convert light energy into electrical energy.
Titanium dioxide can convert light energy into electrical energy just like solar cells, and what makes titanium dioxide different from solar cells is that titanium dioxide can further convert electrical energy into chemical energy. In a sense, titanium dioxide particles are micron-sized solar cells that trigger chemical reactions.
In very simple terms, if enough light energy hits the photocatalytic surface, electrons in the surface generate little ninjas that react with and break down organic pollutants.
In a more scientific explanation, when these light energies are absorbed by the titanium dioxide crystal, they eventually form chemically reactive OH radicals (hydroxyl radicals) on the titanium dioxide surface. This is because water, the raw material for OH radicals, is abundant in the surrounding area.
Volatile organic compounds (VOCs), bacteria, fungal spores, viruses and other airborne contaminants present in the surrounding environment are degraded as they come into contact with the treated surface, improving air quality as it circulates in a space.
Once titanium dioxide has done its work it returns to its original state, ready to absorb more photons and continue the photocatalytic cycle.
That’s basically it. Light that hits a surface coating containing particles of titanium dioxide directly alters the chemical structure of complex molecules that come into contact with the coated surface.
These complex chemicals can be harmful to human health, and neutralising them makes your indoor environment a safer place to be.