The
present work demonstrates the application of a composite of
the zeolite imidazole framework (ZIF-67) and reduced graphene oxide
(rGO), synthesized via a simple hydrothermal route for the sensitive
sensing of ammonia. The successful synthesis of ZIF-67 and rGO composite
was confirmed with structural and spectroscopic characterizations.
A porous structure and a high surface area (1080 m
2
g
–1
) of the composite indicate its suitability as a gas
sensing material. The composite material was coated as a thin film
onto interdigitated gold electrodes. The sensor displays a change
in its chemoresistive property (i.e., resistance) in the presence
of ammonia (NH
3
) gas. A sensor response of 1.22 ±
0.02 [standard deviation (sd)] is measured for 20 ppm of NH
3
, while it shows a value of 4.77 ± 0.15 (sd) for 50 ppm of NH
3
. The fabricated sensor is reproducible and offers a stable
response, while also providing tolerance against humidity and some
other volatile compounds. The average response and recovery times
of the sensor, for 50 ppm NH
3
concentration, are found
to be 46.5 ± 2.12 (sd) and 66.5 ± 2.12 (sd) s, respectively.
The limit of detection of the sensor was found to be 74 ppb.