A  team  of  physicists  from  Immanuel  Kant  Baltic  Federal  University  together with their 

colleagues from National Research Nuclear University MEPhI (NRNU MEPhI) has developed

a tungsten oxide-based detector of hydrogen in gas mixes. They manufactured thin tungsten 

oxide films with various additives and compared their characteristics. One of the film detectors 

demonstrated a 100-fold increase in sensitivity when compared to a control sample. The 

article was published in Thin Solid Films.

Hydrogen is one of the most widely used gases in the world, used in the chemical industry 

and in controlled nuclear fusion experiments. Its molecules have the smallest possible mass 

and size, and it is therefore extremely difficult to store in any vessel, as it leaks from almost 

any opening. Hydrogen leakages are very dangerous for industry, as hydrogen mixed with 

oxygen forms explosive detonating gas. With the development of the hydrogen energy sector, 

the prevention of leakages becomes an important safety issue.

To prevent hydrogen leaks, its concentration in an industrial facility should be constantly 

monitored.  Usually  this  is  done  with  gas  detectors,  the  most  popular  of  which are 

amperometric analyzers. They are based on the ability of gases to change the electrical 

conductivity of metals upon contact with them. In the course of measurements, fixed voltage

 is applied to the ends of a metal plate, and a device measures the strength of current going 

through it. As the strength of current directly depends on the conductivity of a material, when 

the concentration of hydrogen increases, conductivity changes as well. The sensitivity of 

measurements is determined by the properties of the sensor, i.e. the plate under voltage.

BFU scientists and colleagues from NRNU MEPhI studied new materials based on tungsten 

oxide (WOx). One of them was obtained by means of depositing WOx on a silicone carbide 

(SiC) substrate. Another material was developed in the same manner, but the tungsten oxide 

layer was covered with additional platinum coating. Then the scientists determined the 

sensitivity of the two films by applying voltage to them and putting them into an oxygen 

environment. After that, 2 percent of hydrogen was added to it. The material without the 

platinum coating demonstrated a 15-fold increase in the current strength compared to 

pure tungsten oxide. When the same property was measured in the second material, it 

showed a 100-fold increase.

"We have studied nanomaterials that may be used as a basis for hydrogen leakage sensors. 

In  the  course  of  our  work , we identified the requirements for the structural properties of 

these  materials  that  should  secure  high  gas  detecting  efficiency, " says Dr. Alexander 

Goikhman, a co-author of the work and the head of the Research and Educational Center for 

Functional Nanomaterials.