Highly Sensitive and Selective H2S Gas Sensor Fabricated with β-Ga2O3/rGO. (16th June 2020) - Balasubramani, V.
Abstract : Hydrogen Sulfide (H2 S) is a common toxic gas released into the environment mainly during the energy production process from coal and crude oil. H2 S causes several neurological damages to the human body which could also be fatal and thus needs to be monitored. Here, we report the incorporation of reduced graphene oxide (rGO) on β -Ga2 O3 ( β -Ga2 O3 /rGO) sensing layers followed by its deposition on alumina substrate by drop casting method for H2 S gas sensing application. The structure and phase purity of the synthesized β -Ga2 O3, GO and β -Ga2 O3 /rGO samples were characterized using X-ray diffraction (XRD). The gas sensing properties of the coated sensing layers of β -Ga2 O3 and β -Ga2 O3 /rGO were analyzed by Electrochemical Impedance Spectroscopy (EIS) at 100 °C. The gas sensing results revealed superior sensitivity and selectivity of β -Ga2 O3 /rGO towards H2 S detection when compared with different interfering gases (NH3, SO2, CO2 and CO). Nyquist plots and equivalent circuit fitting values clearly indicate that the grain boundary resistance was highly affected in H2 S gas environment (3 ppm) compared to other interfering gases. Based on the findings the gas sensing mechanism is proposed.