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C2H6 and C2H4 gases are two typical decompositions produced by partial discharge of transformer oil. To fully evaluate the feasibility of MoS2-based materials for the detection of C2H6 and C2H4 gases, the adsorption of C2H6 and C2H4 molecules on intrinsic and Au-doped MoS2 monolayer have been studied in this paper by the First-principle of Density Functional Theory (DFT). The adsorption mechanism of MoS2-based monolayer were investigated carefully in terms of adsorption energy, adsorption distance, bandgap structure, charge transfer and density of states (DOS). The calculated results show that the adsorption structures of the C2H6 and C2H4 molecules on Au-doped MoS2 monolayer with larger adsorption energies were stable, and have shorter adsorption distance, higher charge transfer, and stronger orbital hybridization compared with the corresponding MoS2 monolayer adsorption structures. It is concluded that the doped-Au atom affects the electronic structure of MoS2 monolayer to enhance the adsorption capacity. From this aspect, the present research offers a theoretical guidance to the application of Au-doped MoS2 materials as the sensing material for C2H6 and C2H4 gases.

In this work, Cr2O3 nanoparticles, and SnO2 nanofibers were fabricated by a sol–gel process and an electrospinning method, respectively. Gas sensitive materials with high sensitivity to C2H2 gas were obtained by coating Cr2O3 nanoparticles on SnO2 nanofibers. The prepared Cr2O3 nanoparticle-coated SnO2 nanofibers (Cr2O3 NPs. coated SnO2 NFs.) were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and the gas sensing behaviors to C2H2 were studied. The Cr2O3 NPs. coated SnO2 NFs. exhibited low optimal operating temperature, high sensing response, excellent response-recovery time, and long-term stability to C2H2. The optimal operating temperature of the measured material to 20 ppm C2H2 was about 220°C and the C2H2 concentration had a good linear relationship with the response value when the concentration was 60 ppm. In addition, a reasonable gas sensing mechanism was proposed which may enhance the gas sensing performances for the Cr2O3 NPs. coated SnO2 NFs. to C2H2.

Hollow structured nanofibers have attracted much attention in diverse domains owing to their unique physicochemical properties and characteristics. Gas sensing is one of the most promising applications. In electrical engineering, the detection of SF6 decomposing gas products is significant to monitor the insulation status online of gas insulated switchgear (GIS). This mini-review presents the developments of hollow structured nanofibers in synthesis strategies and gas sensing application, especially in the detection of SF6 decomposing gas products, including hydrogen disulfide (H2S), sulfur dioxide (SO2), thionyl fluoride (SOF2), and sulfuryl fluoride (SO2F2). In addition, the gas sensing mechanism of metal oxide hollow nanofibers based gas sensor are discussed.