Analyzing the Effect of Various Reducing Agents and Their Concentrations on Gas Sensing Performance of Graphene Aerogel-Based Ammonia Sensor

The reducing agents and their concentrations used during the synthesis of graphene aerogel (rGO, i.e., reduced graphene oxide) highly effect the chemical characteristics and gas sensing properties of the resulted material. Therefore, in this paper, in order to investigate their effect on gas sensing properties of graphene aerogel, we have synthesized graphene aerogel using three different reducing agents, i.e., thio urea, ammonia, and ethylene glycol. Further, to study the effect of reducing agent’s weight ratio/concentration on the properties, we have used three different weight amounts of thio urea. In total five rGO samples were synthesized and characterized. In order to investigate their gas sensing properties, the gas sensing response characteristics of all five rGO samples were recorded toward 100 ppm ammonia concentration at room temperature. It is found that the two rGO samples, i.e., ammonia-treated rGO aerogel and thio urea-treated rGO aerogel (300 mg), show good gas sensing response toward 100 ppm concentration of ammonia gas (1.4% and 1.21%, respectively) at room temperature, while remaining three samples’ gas sensing responses were very poor (0.102%, 0.205%, and 0.640%).