Highly sensitive hydrogen sensor

Why is it in news?
  • The researchers at the Indian Institute of Technology (IIT) Jodhpur in collaboration with IIT Hyderabad developed a sensor that can detect hydrogen gas even when present at extremely low concentration of 1 part per million (ppm).
More in news
  • Sensitivity range: The sensor has 30% sensitivity to detect hydrogen at 1 ppm concentration and as high as 74% sensitivity when the concentration of the gas is 100 ppm. It takes about 25 seconds to detect hydrogen.
  • Hydrogen:
    (1) Hydrogen gas is a pollution-free, renewable source of energy and is seen as a fuel of choice in the future.
    (२) Hydrogen is highly explosive and flammable in nature. It is a small molecule and can readily mix with air but detecting hydrogen gas leakage become quite difficult particularly as it is colourless and tasteless.
  • Significance:  So a sensor that can detect Hydrogen even when present at very low concentration becomes essential and this is where the current work becomes important.
  • Working:
    (१) The change in resistance is a function of the concentration of nanofibres loaded on the zinc oxide semiconductor, temperature and the concentration of hydrogen gas.
    (२) In the presence of hydrogen the resistance reduces drastically leading to more current flow, thus suggesting hydrogen gas leakage.
  • Comparing with other hydrogen sensors:
    (1) Sensor can detect hydrogen only when the temperature is moderate- 150 degree C. Since, high temperature is needed to activate the chemical reaction between hydrogen and oxygen.
    (2) Other hydrogen sensors require about 250 degree C to activate the chemical reaction.
    (3) This hydrogen sensor is able to achieve the same at 150 degree C.
    (4) The researchers are able to activate the chemical reaction at a relatively lower temperature as carbon nanofibres are used.
    (5) The nanomaterial increases the surface area and acts as a catalyst to reduce the activation energy.
  • Future work: The next goal is to develop a prototype by integrating the sensor with a microheater.
Source
The Hindu




Posted by Jawwad Kazi on 26th Aug 2019
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