The titanium dioxide-based technology reduced gaseous pollutants by 30–70% in laboratory trials, but its real-world effectiveness remains to be established.

 

New Delhi: In a promising development in the fight against Delhi’s air pollution, researchers at the Indian Institute of Technology, Madras (IIT Madras) have developed a titanium dioxide-based coating that could help break down certain airborne pollutants when exposed to sunlight.

The technology, which is being explored in collaboration with the Delhi government, could turn roads, building walls and glass facades into surfaces capable of helping reduce specific gaseous pollutants. Laboratory experiments have reportedly recorded reductions of 30–70% under the tested conditions, offering a potential new approach to tackling the capital’s persistent air-quality crisis.

The research comes as Delhi continues to battle hazardous air pollution, particularly during winter, when low wind speeds and unfavourable weather conditions often allow pollutants to accumulate near the ground.

How the ‘Smog-Eating’ Coating Works

The technology uses titanium dioxide (TiO₂), a material known for its photocatalytic properties. When exposed to suitable light, it triggers chemical reactions on the treated surface that can break down certain pollutants.

The IIT Madras team is studying its effectiveness against gaseous pollutants, including nitrogen oxides and volatile organic compounds (VOCs), which contribute to urban air pollution.

The concept is to transform ordinary infrastructure into pollution-fighting surfaces. If proven effective outdoors, the coating could potentially be applied to selected roads, buildings and glass structures to help degrade pollutants that come into contact with them.

However, the results depend on several factors, including the type of surface, exposure to sunlight and the concentration of pollutants.

Laboratory Results Offer Hope

Laboratory trials have indicated a 30–70% reduction in gaseous pollutants after 10 hours of sunlight exposure, with performance varying according to experimental conditions. Glass surfaces reportedly delivered particularly promising results.

Researchers are also testing the coating on other materials, including road tar and painted surfaces, to understand how its performance changes across different applications.

The findings are encouraging, but laboratory results do not necessarily translate into similar reductions in outdoor pollution. Wind, dust accumulation, sunlight intensity and the continuous movement of emissions could all influence the coating’s effectiveness in Delhi’s complex urban environment.

Further field testing will be essential to determine whether the technology can deliver measurable improvements in real-world conditions.

Delhi Government Joins Hands with IIT Madras

The Delhi government signed a memorandum of understanding with IIT Madras on March 13, 2026, to examine the potential of photocatalytic surfaces as an additional tool for controlling air pollution.

The project involves evaluating the technology’s performance, practical applications and suitability for use under Delhi’s environmental conditions. The research has progressed from laboratory experiments towards further testing, with additional time reportedly allocated to complete the assessment.

The findings could help policymakers determine whether the coating is suitable for pilot projects and, eventually, wider use on urban infrastructure.

A Promising Solution, but Not a Silver Bullet

Despite its potential, the technology has an important limitation: it is designed to target certain gaseous pollutants, not particulate matter such as PM2.5 and PM10, which poses a major health risk in Delhi.

This means the coating cannot independently solve the capital’s air-pollution problem. Vehicle exhaust, construction dust, industrial emissions, road dust and seasonal crop-residue burning continue to require targeted and sustained intervention.

Its long-term value will also depend on durability, maintenance costs, performance under varying weather conditions and the extent to which it can reduce pollution beyond controlled experiments.

Researchers will need to establish these factors before the technology can be considered for large-scale deployment.

What Lies Ahead?

If further trials demonstrate consistent results, titanium dioxide-based coatings could offer an additional way to tackle selected air pollutants through existing urban infrastructure. High-exposure areas and suitable building surfaces could be considered for pilot applications, subject to scientific evaluation.

For Delhi, the research signals an effort to explore technological solutions alongside conventional pollution-control measures. Whether the coating can make a meaningful difference will ultimately depend on its performance outside the laboratory.

The innovation offers a potentially useful addition to the fight against toxic air, but its success will be measured by actual pollution reductions—not laboratory results alone.