Investigation of pristine graphite oxide as room-temperature chemiresistive ammonia gas sensing material

Investigation of pristine graphite oxide as room-temperature chemiresistive ammonia gas sensing material

WoS Article

Graphite oxide has been investigated as a possible room-temperature chemiresistive sensor of ammonia in a gas phase. Graphite oxide was synthesized from high purity graphite using the modified Hummers method. The graphite oxide sample was investigated using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, thermogravimetry and differential scanning calorimetry. Sensing properties were tested in a wide range of ammonia concentrations in air (10–1000 ppm) and under different relative humidity levels (3%–65%). It was concluded that the graphite oxide–based sensor possessed a good response to NH3 in dry synthetic air (ΔR/R0 ranged from 2.5% to 7.4% for concentrations of 100–500 ppm and 3% relative humidity) with negligible cross-sensitivity towards H2 and CH4. It was determined that the sensor recovery rate was improved with ammonia concentration growth. Increasing the ambient relative humidity led to an increase of the sensor response. The highest response of 22.2% for 100 ppm of ammonia was achieved at a 65% relative humidity level.

Graphite oxide has been investigated as a possible room-temperature chemiresistive sensor of ammonia in a gas phase. Graphite oxide was synthesized from high purity graphite using the modified Hummers method. The graphite oxide sample was investigated using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, thermogravimetry and differential scanning calorimetry. Sensing properties were tested in a wide range of ammonia concentrations in air (10–1000 ppm) and under different relative humidity levels (3%–65%). It was concluded that the graphite oxide–based sensor possessed a good response to NH3 in dry synthetic air (ΔR/R0 ranged from 2.5% to 7.4% for concentrations of 100–500 ppm and 3% relative humidity) with negligible cross-sensitivity towards H2 and CH4. It was determined that the sensor recovery rate was improved with ammonia concentration growth. Increasing the ambient relative humidity led to an increase of the sensor response. The highest response of 22.2% for 100 ppm of ammonia was achieved at a 65% relative humidity level.

graphite oxide; chemiresistive gas sensor; sensitivity; ammonia

graphite oxide; chemiresistive gas sensor; sensitivity; ammonia

BANNOV, A.; PRÁŠEK, J.; JAŠEK, O.; ZAJÍČKOVÁ, L.

2018

09.02.2017

MDPI AG

Switzerland

1424-8220

SENSORS

17

2

Swiss Confederation

320

329

10

http://www.mdpi.com/1424-8220/17/2/320

http://hdl.handle.net/11012/63896

2017-bannov-sensors