Indian Institute of Technology Madras is Testing a Titanium Coating That Can Break Down Air Pollutants

     According to India Today, the Indian Institute of Technology (IIT) Madras is testing a titanium coating in the laboratory that breaks down air pollutants. In testing so far, it has broken down 30-70% of gaseous pollutants, with glass surfaces performing best. The coating does not break down particulate matter, which is the main pollutant of concern, only gaseous pollutants, but it has the ability to significantly improve overall air quality and lower the air quality index (AQI) number.

     Delhi’s air pollution is the worst in the fall and winter. Burning crop residues in late fall is a huge air quality problem.

“…the capital's Air Quality Index (AQI) stays above 300 on most days, climbing up to 800 and even higher on some days.”

     Temperature inversions often make the problem worse, concentrating pollutants lower to the ground where humans breathe.

“Somnath Chanda Roy of the IIT Madras' department of physics, who is working on the smog project, said the coating is a photocatalyst: when titanium dioxide absorbs light, it drives reactions on its surface that break down pollutant molecules coming into contact with it.”

“Applied to roads, building walls and glass facades, it would turn surfaces a city already has into ones that treat the air around them.”

     The gaseous pollutants that the titanium coating addresses include carbon monoxide, carbon dioxide, organic compounds such as aldehydes and alcohols, and nitric and nitrous oxides.

     Three surfaces that have been chosen to be coated are road tar, building paint, and glass. Many of the city’s office buildings are glazed with glass surfaces. As noted, it works best on these glass surfaces. The experiments include varying the catalyst thickness and pollutant concentrations.

     In the winter, the gaseous pollutants mix with particulates and make up a significant share of pollutants. The titanium coating technology does have limitations. One previous study showed that it works better in the lab than in real-world settings, cutting only a small amount of NOx pollutants.

"The technology can only be a complement to existing pollution controls and ideally lab tests should be followed by field tests," said an epidemiologist at the All India Institute of Medical Sciences (AIIMS), New Delhi who studies pollution's health related impact.

“Meanwhile, Roy said a preliminary report had gone to the Delhi government in August, and testing continues. Officials will review the data first, after which a comprehensive report will lay out what works and what does not, Roy said.

  

 

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Delhi air crisis: Can IIT Madras' new surface coating offer a breath of relief?  India Today Health Desk. October 23, 2026. Delhi air crisis: Can IIT Madras' new surface coating offer a breath of relief?