Reduced graphene oxide as ammonia gas sensor

Reduced graphene oxide (rGO) film sensors were fabricated by thermally reduced graphene oxide (GO) at various temperatures. According to the morphological analysis, it was found that rGO synthesized at 200 °C exhibited a crumpled plate-like structure with a much larger surface area within the range of 195.82 m2 g−1, above that of GO. The structural analysis demonstrated the presence of a significant concentration of oxygen functional groups on a typical GO surface, which decreased after the reduction process. Additionally, the peak corresponding to the (001) plane shifted from 13.7° to 25.65° upon increasing the temperature to 200 °C. The rGO films were utilized as a sensor for NH3 gas at varying operational temperatures. The sensitivity, response, and recovery times of the rGO and GO sensors were investigated. The rGO sensor synthesis at 200 °C was found to have a high response of 11% when operated at a working temperature of 200 °C.