When we think of growing cities, we tend to relate them to having high rise buildings and advanced architecture. However, the construction of these new buildings can also increase pollution as they use up so much energy to function, thus leading to global warming. Is there a possibility that buildings can actually help tackle air pollution? Well, there has already been a development in the use of titanium dioxide to help rectify this issue, and here’s how.

Why use titanium dioxide?

Research has been conducted around the substance which suggests that using titanium dioxide in buildings can help to reduce the nitrogen oxide and dioxide levels within a busy London street. It removes the oxides from the air through the process of ‘photo-catalysis’ – a process which speeds up the natural chemical reaction of photolysis. It essentially converts the nitrogen oxides into nitrate salts that are harmless. The process of photo-catalysis can remove the polluting matter from the air and prevent nitrogen oxides being visible in the air.

How can it be used?

How titanium dioxide has been used is by painting buildings and relevant materials around the surrounding area with the substance. Using it on buildings means that this reaction of converting the nitrogen dioxide into smaller, harmless nitrate salts are created on a larger scale. What’s extra special about the substance is that it can be used cost-effectively because it can’t be consumed or degraded. This makes the coatings long-lasting and it is continuously removing pollutants from the air.

A group of students based at the University of California Riverside made the most of this concept and applied titanium dioxide to the roof tiles of one of their buildings. Each single roof tile was covered in titanium dioxide and each time sunlight hits the roof, it was being absorbed throughout the day and pollution was removed from the air.

Photo-catalysis potential 

There are many deaths that happen globally due to air pollution. Considering the number of buildings and estate projects that are constantly present in busy cities, applying titanium dioxide to buildings on a wider scale will help tackle and reduce the high levels of pollution that are currently present.

The use of titanium dioxide being used as a photo-catalytic material has been questioned, however. Most notably, by the UK’s Air Quality Expert Group. Further research was made into the substance and it was actually found that using titanium dioxide was highly effective in reducing the number of pollutants present in the air. Particularly when used against large surface areas and when it was exposed to reasonable natural light levels.

Utilising methods to reduce air pollution through buildings is a great opportunity. For extremely busy cities, this will be highly relevant considering the high levels of pollution and the number of buildings that are present. Although there could be limitations to using the substance, there are great advantages of using titanium dioxide when combined with other measures. One of the main benefits to business and building owners is that there is little invasive internal work which needs carrying out, such as the installation of stainless steel ducting and ventilation. This reduces disruption to the workplace and lost profits. Essentially, it should be looked upon as a cost-effective and efficient way of how major cities can reduce the presence of air pollution in the city.

Elliot Preece