Nanostructured Ce/CeO2-rGO: Highly Sensitive and Selective Electrochemical Hydrogen Sulphide Sensor

Herein, cerium/ceriumoxide nanoparticles have been decorated on reduced graphene oxide (Ce/CeO 2 -rGO) for room temperature electrochemical determination of H 2 S in 0.5 M KOH electrolyte. There is a superior linear correlation between the peak current density and H 2 S content in the tested range of 1–5 ppm. Moreover, compare to other abundant gases shows no response such as CO 2 at the potentials of H 2 S sensing, confirms no interfere with H 2 S detection. And it reveals that the Ce/CeO 2 -rGO nanocomposites is highly selective and sensitive system for the detection of H 2 S gas sensing. Ce/CeO 2 -rGO synthesized by simple chemical approach and further characterized by X-ray diffraction (XRD), Furrier transform infra-red (FTIR), Field emission-scanning electron microscopy (FE-SEM) coupled energy dispersive analysis of X-ray (EDAX) and BET-surface area measurements confirms the porosity of synthesized nanomaterial and homogeneous decoration of Ce/CeO 2 nanoparticles on rGO sheets. The electrochemical studies i.e. linear sweep voltammetry (LSV) of Ce/CeO 2 -rGO demonstrates the electrochemical H 2 S gas sensing at room temperature with lower gas concentration i.e 1 ppm detection at low concentration. Furthermore, the applcablity of sensor the analytical parametrtrs like LOD and LOQ has been calculated and were found to be 0.92 and 9.22 µM respectively. The sensing mechanism is believed tobe based on the modulation of the current and applied potential path across the electron exchange between the cerium oxide and rGO sites when exposed to H 2 S.