Ag decorated CuGaO2 nanosheets for enhanced ethylene glycol detection

Metal oxide semiconductors stand at an essential frontier of chemiresistive substance for gas sensor assembly to detect the volatile organic compounds, especially in case of the trace amount related to human health. In this work, we present a new gas sensor based on hydrothermally synthesized CuGaO2 nanosheets with Ag decoration, which performs an enhanced selectivity, sensitivity, and response/recovery speed towards ethylene glycol. Based on the structural characterization and systematic gas detection results, the gas sensing mechanism is elucidated by the first principles calculations and energy band theoretic analysis, in which the extraordinary gaseous adsorption and charge transfer onto the solid surface is responsible for the high susceptibility of Ag decorated CuGaO2 to ethylene glycol. Meanwhile, Ag hybridization is further confirmed to provide the additional approach to boost the efficiency of electron transfer. It is an innovative perspective to study the chemiresistive gas sensing by comparing the preference of charge transfer from the adsorbed organic gas molecule towards the hybridized solid surface, which presents a new route to design the material system of advanced sensing devices for the specific applications.