Detecting nitrogen dioxide: Revolutionary new weapon in air pollution fight

October 28, 2015, RMIT University

People could soon be using their smartphones to combat a deadly form of air pollution, thanks to a potentially life-saving breakthrough by RMIT University researchers.

Experts have developed the first low-cost and reliable method of detecting nitrogen dioxide (NO2), a significant air pollutant than contributes to more than seven million deaths worldwide each year, according to the World Health Organization (WHO).

The gas increases the risk of respiratory disorders in children and can severely affect the elderly in particular.

Project leader Professor Kourosh Kalantar-zadeh, from RMIT's Centre for Advanced Electronics and Sensors (CADES), said the negative impact of nitrogen dioxide could be prevented by access to personalised, highly selective, sensitive and reliable monitoring systems that could detect harmful levels of the gas early.

"The revolutionary method we've developed is a great start to creating a handheld, low-cost and personalised NO2 sensor that can even be incorporated into smartphones," Kalantar-zadeh said.

"Not only would it improve the quality of millions of people's lives, but it would also help avoid illness caused by nitrogen dioxide poisoning and potentially even death."

The main contributors of nitrogen dioxide are the burning of fossil fuels, particularly in coal-fired power stations and diesel engines (as highlighted by the recent Volkswagen emissions scandal), which can impact on the health of people in urban areas.

"A lack of public access to effective monitoring tools is a major roadblock to mitigating the harmful effects of this gas but current sensing systems are either very expensive or have serious difficulty distinguishing it from other gases," Kalantar-zadeh said.

An electron microscope image of the NO2 sensitive layer made of atomically thin flakes of tin disulphide, magnified 500,000 times.
"The method we have developed is not only more cost-effective, it also works better than the sensors currently used to detect this dangerous gas."

Kalantar-zadeh developed the new method for sensing nitrogen dioxide together with fellow RMIT researchers and colleagues from the Chinese Academy of Sciences.

The sensors, which operate by physically absorbing nitrogen dioxide gas molecules onto flakes of tin disulphide, not only increase the level of sensitivity to accepted EPA standards, but outperform any other nitrogen dioxide sensing solutions on the market.

Tin disulphide is a yellowish-brown pigment generally used in varnish for gilding. To create sensors, researchers transformed this material into flakes just a few atoms thick.

The large surface area of these flakes has a high affinity to molecules that allows its highly selective absorption.

A research paper by the team, which includes first author Dr Jian Zhen Ou, has been published in the prestigious journal ACS Nano.

Explore further: New insight into improving air quality measurements

More information: Li Su et al. High-Performance Organolead Halide Perovskite-Based Self-Powered Triboelectric Photodetector, ACS Nano (2015). DOI: 10.1021/acsnano.5b04995

Related Stories

New insight into improving air quality measurements

March 12, 2015

Researchers from the National Physical Laboratory (NPL) and King's College London have identified a mechanism which is responsible for under-reporting of peak nitrogen dioxide concentrations at some air quality monitoring ...

Gas sensors sound the smoldering fire alarm

September 2, 2015

Smoke detectors are everywhere, but still thousands of people die in fires annually. Fire gas detectors, which detect carbon monoxide and nitrogen oxide, identify fires at an early stage. Thanks to a new measurement principle ...

An up-close look at what air pollution is doing to your body

October 17, 2014

We are all aware that air pollution can be bad for our health – the World Health Organisation estimated that ambient air pollution caused 3.7 million premature deaths worldwide in 2012 – yet what exactly happens to your ...

Recommended for you

Engineering cellular function without living cells

March 25, 2019

Genes in living cells are activated – or not – by proteins called transcription factors. The mechanisms by which these proteins activate certain genes and deactivate others play a fundamental role in many biological processes. ...

What ionized the universe?

March 25, 2019

The sparsely distributed hot gas that exists in the space between galaxies, the intergalactic medium, is ionized. The question is, how? Astronomers know that once the early universe expanded and cooled enough, hydrogen (its ...

Catalyst advance removes pollutants at low temperatures

March 25, 2019

Researchers at Washington State University, University of New Mexico, Eindhoven University of Technology, and Pacific Northwest National Laboratory have developed a catalyst that can both withstand high temperatures and convert ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

christian_bellacanzone
1 / 5 (2) Oct 30, 2015
The article in more information is not the right one!

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.