Investigation of Ammonia Gas Sensing Properties of Graphite Oxide

In this paper a graphite oxide is investigated as a possible sensing layer of room temperature ammonia chemiresistive gas sensor. The sensing properties were tested in a wide range of ammonia concentrations in air (10-1000ppm) and under different humidity levels (3-65%). It was concluded that the graphite oxide based sensor possessed high response to NH3 in synthetic air (ΔR/R0 ranged from 2.5 to 7.4% for concentrations of 100-500ppm 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 of ambient relative humidity led to increase of sensor response. The highest response of 22.2% for 100ppm of ammonia was achieved at 65% relative humidity level.