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Abstract
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Reliable, sensitive and selective ammonia gas
sensing at room temperature is very important for monitoring
the environment for hazardous pollutants. In this study,
ammonia (NH3) gas sensor is proposed based on
polyaniline/three-dimensional reduced graphene oxide
(PANI/3D-RGO) hybrid samples, which are loaded on glass
substrates by electrochemical polymerization method. The
PANI/3D-RGO hybrid samples with different weight
percentages of 3D-RGO (weight %=0.05, 0.2, 0.5 and 1) are
characterized by field emission-scanning electron microscopy,
Fourier transform infrared and X-ray diffraction. The specific
surface area is analyzed by the Brunauer-Emmett-Teller (BET)
equation. The gas-sensing performances of the fabricated
sensors indicate that PANI/3D-RGO (0.2wt. %) exhibits the
best response for 50 ppm NH3 gas at room temperature, this
sensor response to lower concentrations of NH3 (5ppm, 10 ppm
and 25 ppm) too. The PANI/3D-RGO (0.2wt. %) hybrid sensor
shows represent response values of about 3.72 and acceptable
response and recovery times (98 s and 288 s) to 50 ppm NH3
which is about 4.27 fold higher than that of pure PANI in 50
ppm NH3 gas. The excellent sensing performance of the
developed gas sensor can be attributed to the synergetic effects
of PANI and 3D-RGO, π-π interaction between the two
components, efficient increase in hole-like carriers and
substantial increase in active sites.
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