| Significant developments have been made in the area of metal oxide semiconducting ceramic gas sensors since
its invention. Currently, these sensors are extensively used for domestic, industrial and environmental applications.
These are the simple type of gas sensors possessing superiority due to compact size, simple fabrication technique,
durability, low cost, minimal power consumption and simple electronic circuits. Tin dioxide (SnO2) has been widely
investigated as the most challenging semiconducting material for its strong gas sensing properties for more than
five decades. In this review, we have focussed mainly on the response of SnO2 and SnO2 based modified materials
towards hydrogen gas in the parts per million (ppm) to percentage (%) level. It is a highly challenging task to
fabricate SnO2 based sensor devices exhibiting high sensitivity, stability and above all selectivity towards hydrogen.
Though we have been partially successful in fabricating SnO2 based sensor units exhibiting high sensitivity and
selectivity towards hydrogen, commercialization of such devices are still a distant reality.
[Keywords: Semiconducting metal oxides, Hydrogen gas sensor, Tin dioxide, Catalyst, Debye length] |
