Deployment of low-cost green synthesized SnO2 and CuO nanoparticles bi-layer based transistor for H2S detection

The detection of Hydrogen sulfide (H2S) gas at room temperature measurement has gained interest owing to its low-power consumption, high stability and reducing the risk of explosion within the sight of flammable gases. In this study, we present a novel low-cost and environmental-friendly approach in developing SnO2 and CuO nanoparticles (green approach) and their deployment in transistor (bi-layer approach) for the detection of hydrogen sulfide (H2S) vapors. The crystallite size of as-synthesized SnO2 and CuO NPs were revealed with aid of diffraction peaks which were found to be 14 nm and 19 nm respectively and the elemental composition with structural morphology (spherical) were determined by EDAX and Fe-SEM analysis respectively. The CuO nanoparticles interaction with the surface of SnO2 affirms a p-n junction formation with large electron-hole movements, while the interaction of H2S gas molecules on to the surface of CuO leads to the formation of CuS which awfully reduces electrical resistance enhancing the electrical conductivity and the sensor response. The high sensitivity of 1.86 μA/ppm and selectivity response of 89.46 % was achieved for the exposure of H2S analyte among other analytes exposed such as NO2, CO, C2H5OH and C3H8. The results demonstrate that sensor designed is potent for the use in industrial, environmental, and safety applications, contributing to the mitigation of H2S-related risks.