Enhanced H2S sensing characteristics of CuO-NiO core-shell microspheres sensors

CuO-NiO core-shell microspheres were prepared through a simple two-step hydrothermal method. The crystal structure, valence state and morphology of the CuO-NiO core-shell were studied by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The surface characteristic of the microspheres was investigated by the nitrogen adsorption method. To demonstrate the use of CuO-NiO core-shell materials, a chemical gas sensor has been fabricated and investigated. The results revealed that core-shell microspheres sensor exhibited enhanced H2S sensing properties compared with bare CuO microspheres. The enhanced gas responses were discussed in relation to catalytic effect of NiO flower-like shell as well as formation of heterojunction.