A hydrogen sulfide sensor or H₂S sensor is a gas sensor for the measurement of hydrogen sulfide.

Principle

The H₂S sensor is a

metal oxide semiconductor The metal–oxide–semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET) is a type of field-effect transistor (FET), most commonly fabricated by the thermal oxidation, controlled oxidation of silicon. It has an insulated gate, the ...

(MOS) sensor which operates by a reversible change in resistance caused by

adsorption Adsorption is the adhesion of atoms, ions or molecules from a gas, liquid or dissolved solid to a surface. This process creates a film of the ''adsorbate'' on the surface of the ''adsorbent''. This process differs from absorption, in which ...

and

desorption Desorption is the physical process where a previously adsorbed substance is released from a surface. This happens when a molecule gains enough energy to overcome the activation barrier of the bounding energy that keeps it in the surface. There ...

of hydrogen sulfide in a film with hydrogen sulfide sensitive material like

tin oxide Tin is a chemical element with the symbol Sn (from la, stannum) and atomic number 50. Tin is a silvery-coloured metal. Tin is soft enough to be cut with little force and a bar of tin can be bent by hand with little effort. When bent, t ...

thick film Thick-film technology is used to produce electronic devices/modules such as surface mount devices modules, hybrid integrated circuits, heating elements, integrated passive devices and sensors. Main manufacturing technique is screen printing ( stenc ...

s and

gold Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile me ...

thin film A thin film is a layer of material ranging from fractions of a nanometer ( monolayer) to several micrometers in thickness. The controlled synthesis of materials as thin films (a process referred to as deposition) is a fundamental step in many ...

s. Current response time is 25 ppb to 10 ppm < one minute.

Applications

This type of sensor has been under constant development because of the toxic and corrosive nature of hydrogen sulfide: *The H₂S sensor is used to detect hydrogen sulfide in the

hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...

feed stream of fuel cells to prevent

catalyst poisoning Catalyst poisoning refers to the partial or total deactivation of a catalyst by a chemical compound. Poisoning refers specifically to chemical deactivation, rather than other mechanisms of catalyst degradation such as thermal decomposition or physic ...

and to measure the quality of guard beds used to remove sulfur from hydrocarbon fuels./-

Research

* 2004 - a nanocrystalline SnO₂– Ag on ceramic wafer sensor is reported.Micromachined nanocrystalline silver doped SnO₂ H₂S sensor
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References

{{DEFAULTSORT:Hydrogen Sulfide Sensor Sensors Gas sensors

Principle

Applications

Research

See also

References