Monoclinic α-Ag2S hollow nanospheres: Promising candidates for ethanol gas sensors at room-temperature

Silver sulfide (Ag2S) hollow sphere-like nanostructures were synthesized by a simple hydrothermal route. X-ray powder diffraction (XRD), X-ray energy dispersive analysis spectrum (EDS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the as-obtained products, which were monoclinic alpha-Ag2S hollow nanospheres (HNSs) with the inner and outer diameters of about 200 nm and 700 nm, respectively. Particularly, the room-temperature ethanol sensitivity of Ag2S HNSs was investigated by the surface photovoltage (SPV) technique. When the concentration of ethanol reached 80 ppm the sensitivity of Ag2S HNSs was 2.4 times higher than that of Ag2S CPs, demonstrating that Ag2S HNSs had much larger photovoltage sensing than the counterpart CPs, which indicated broad potential applications in ethanol sensors. (c) 2014 Elsevier B.V. All rights reserved.