High sensitive reduced graphene oxide-based room temperature ionic liquid electrochemical gas sensor with carbon-gold nanocomposites amplification

Abstract

Gas sensors have received extensive attractions due to their critical roles in environmental monitoring, industry manufacture and human safety. This paper for the first time introduces carbon-gold nanocomposites on a reduced graphene oxide based electrochemical gas sensor for high sensitive gas detection. Carbon-gold nanocomposites (CGNs) were synthesized by glucose carbonization and gold nanoparticles deposition using the hydrothermal method. Reduced graphene oxide (RGO) was electrochemically deposited on a screen-printed gold electrode with subsequent modification of CGNs. To achieve long lifetime and good stability, thin-film room temperature ionic liquid (RTIL) was utilized as the electrolyte featuring negligible evaporation and large potential window, thus implementing the high sensitive RTIL-based electrochemical gas sensor. The amplification effect of RGO and CGNs modification was investigated using cyclic voltammetry, chronoamperometry and transient double potential amperometry (DPA), which reveals the significant enhancement of sensor performance by synergic application of RGO and CGNs. The sensor was calibrated for oxygen detection from 0.42% to 21% with good sensitivity and linearity. The reproducibility of the sensor using chronoamperometry and transient DPA was also studied with excellent reproducibility. The study paves a new way to implementing high sensitive electrochemical gas sensors for rapid monitoring of gas exposure.