organic compounds in the concentration range of 200–1000 ppm (Li et al. 2009).
The polyaniline–silver nanocomposite was employed for the successful sensing of
acetone vapor, and the sensor exhibited the fastest response, good reproducibility,
and long-term stability in comparison with pure polyaniline sensor (Choudhury et al.
2009). Nanocrystalline barium hexaferrite particles have been revealed as promising
sensor for the fast and reproducible detection of acetone and ethanol vapors at
concentration as low as 20 ppm (Karmakar et al. 2014).
10.5.5 Ozone
Ozone consisting of three oxygen atoms bound together is unstable and highly
reactive. Ozone found in the stratosphere has been called “good” ozone as it protects
the earth’s surface from dangerous ultraviolet light. Ozone in troposphere, the lowest
layer of the atmosphere, is man-made air pollutant released from internal combustion
of engines and power plants, and that ozone is often termed “bad” ozone. Ozone can
be used as a bleach and a sterilization agent for air and drinking water. However,
exposure to ozone has been linked to have significant adverse effects like premature
mortality, range of morbidity health, asthma symptom, decrease of vegetation
productivity of some crops, injury of flowers and shrubs, etc. Ozone acts as a
reactive deodorizing agent and damages synthetic materials, rubber, dyes, paints
and coatings, cotton, acetate, nylon, polyester, and other textiles.
Nanosized indium oxide single crystals deposited onto alumina substrates were
reported as ozone gas sensor with short response and recovery times even for
concentrations as low as 60 ppb (Epifani et al. 2008). A series of nanocrystalline
100
80
60
40
20
0
50
100
200
300
400
500
Concentration (ppm)
Sensitivity (I
air /I
gas )
Formaldehyde
Toluene
Methanol
Fig. 10.24 Selectivity of porous hierarchical indium oxide micro-/nanostructures for methanol gas
sensing. (Reprinted with permission of American Chemical Society from Liu et al. 2010)
10 Nanomaterials Based Sensors for Air Pollution Control
383
The polyaniline–silver nanocomposite was employed for the successful sensing of
acetone vapor, and the sensor exhibited the fastest response, good reproducibility,
and long-term stability in comparison with pure polyaniline sensor (Choudhury et al.
2009). Nanocrystalline barium hexaferrite particles have been revealed as promising
sensor for the fast and reproducible detection of acetone and ethanol vapors at
concentration as low as 20 ppm (Karmakar et al. 2014).
10.5.5 Ozone
Ozone consisting of three oxygen atoms bound together is unstable and highly
reactive. Ozone found in the stratosphere has been called “good” ozone as it protects
the earth’s surface from dangerous ultraviolet light. Ozone in troposphere, the lowest
layer of the atmosphere, is man-made air pollutant released from internal combustion
of engines and power plants, and that ozone is often termed “bad” ozone. Ozone can
be used as a bleach and a sterilization agent for air and drinking water. However,
exposure to ozone has been linked to have significant adverse effects like premature
mortality, range of morbidity health, asthma symptom, decrease of vegetation
productivity of some crops, injury of flowers and shrubs, etc. Ozone acts as a
reactive deodorizing agent and damages synthetic materials, rubber, dyes, paints
and coatings, cotton, acetate, nylon, polyester, and other textiles.
Nanosized indium oxide single crystals deposited onto alumina substrates were
reported as ozone gas sensor with short response and recovery times even for
concentrations as low as 60 ppb (Epifani et al. 2008). A series of nanocrystalline
100
80
60
40
20
0
50
100
200
300
400
500
Concentration (ppm)
Sensitivity (I
air /I
gas )
Formaldehyde
Toluene
Methanol
Fig. 10.24 Selectivity of porous hierarchical indium oxide micro-/nanostructures for methanol gas
sensing. (Reprinted with permission of American Chemical Society from Liu et al. 2010)
10 Nanomaterials Based Sensors for Air Pollution Control
383