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Abstract: The ZnO nanowires have been prepared and studied as the sensing element for the detection of ammonia. The ZnO nanowires were first synthesized by evaporating high purity zinc pellets at 900°C and then distributed onto the electrode surfaces of quartz crystals at room temperatures. Gas sensitive properties of ZnO nanowires layer were studied in terms of the quartz crystal microbalance (QCM) at room temperature. It is found that the obtained response of the sensors varied with the thickness of the ZnO nanowires layer. ZnO nanowires showed high sensitivity to ammonia in the range of 40–1000ppm. The response time of the sensor was as fast as ∼5s at any concentration (40–1000ppm) of ammonia gas. The ZnO nanowires-coated sensors have a good frequency stability and reproducibility. All results demonstrated that the ZnO nanowire was a potential gas sensing material for practical use. [Copyright &y& Elsevier]

Semiconductor heterostructures based on transition metal dichalcogenides provide a broad platform to research two-dimensional nanomaterials and design atomically thin devices for fundamental and applied interests. The MoS 2 /WS 2 heterostructure was prepared on SiO 2 /Si substrate by chemical vapor deposition (CVD) in our research. And the optical properties of the heterostructure was characterized by Raman and photoluminescence (PL) spectroscopy. The similar 2 orders of magnitude decrease of PL intensity in MoS 2 /WS 2 heterostructures was tested, which is attribute to the electrical and optical modulation effects are connected with the interfacial charge transfer between MoS 2 and WS 2 films. Using MoS 2 /WS 2 heterostructure as channel material of the phototransistor, we demonstrated over 50 folds enhanced photoresponsivity of multilayer MoS 2 field-effect transistor. The results indicate that the MoS 2 /WS 2 films can be a promising heterostructure material to enhance the photoresponse characteristics of MoS 2 -based phototransistors. [ABSTRACT FROM AUTHOR]

[Display omitted] • It was demonstrated that the MOF (ZIF-8) could facilitate the gas-sensitive performances of WO 3 nanofibers on the repeatability and recovery capability. • Toward SF 6 decomposition products, the temperature-dependent and time-dependent in-situ DRIFT spectra of the nanofibers were firstly employed to reveal the sensitive mechanism. • The results of in-situ DRIFT experiments were consistent with those of gas-sensitive tests, and it has verified the catalytic effect of ZIF-8. • The method used in this work can be extended to other target gases, providing the guidance for the synthesis of the novel gas-sensitive materials. SF 6 decomposition products are of significance to the diagnosis of gas insulated switchgear (GIS) equipment. Amounts of previous literature have employed a series of advanced materials to detect these characteristic products (H 2 S, SO 2 , SO 2 F 2 and SOF 2). However, the development of the gas-sensitive mechanism is seriously lagging behind the gas-sensitive materials. This work has synthesized the MOF-modification WO 3 nanofibers (NFs) via electrospinning, and further investigated its sensitivity toward four gas analytes. With the assistance of in-situ diffuse reflectance infrared Fourier transform (DRIFT) spectra, the sulfites and sulfates sourced from the SO 2 adsorption was regarded as the essence of the material poisoning. At the particular bands, the in-situ experiments have indicated the composites performed larger absorbance intensity and better recovery capability than the pristine WO 3 , which were consistent with the results of gas-sensing experiments. This work provides the guidance for improving the performance of nanomaterials toward SF 6 decomposition products by MOF doping. [ABSTRACT FROM AUTHOR]

The tube-brush-like ZnO nanostructures were synthesized by hydrothermal method using electrospinning polyvinylpyrrolidone (PVP) nanofibers as templates. The photocatalytic activity of as-grown samples was investigated by photo-degradation of Rhodamine B (RhB). The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV/visible absorption spectroscopy (UV–vis) and photoluminescence (PL) spectroscopy. It was found that the morphologies of the prepared ZnO were tube-brush-like nanostructures. With the grown time increasing, the crystal and the optical properties were improved. In the photocatalytic experiment, the tube-brush-like ZnO nanostructures photocatalytic activity was enhanced the degradation of RhB was up to 98% after 2 h of irradiation. The tube-brush-like ZnO nanostructures showed higher photocatalytic activity because of the special surface morphology. [ABSTRACT FROM AUTHOR]

Abstract: To overcome the limitations of the conventional inhibition method for mechanism study, here we developed a combined CLSM technique as an alternative approach to evaluate and explain the antibacterial process of nanostructure at single cell level. Three different nanostructures (dumbbell-shaped ZnO, rod-shaped ZnO and ZnO/Ag composites) were examined here as a model system. Their antibacterial processes against Escherichia coli (E. coli) were quantitatively studied in detail. According to the obtained time-dependent mean fluorescence intensity (MFI) decay dynamics, an interesting two-step cellular disruption process was observed and discussed for the first time. The combined CLSM technique described here is superior to standard growth method for they can provide a more detailed and reliable description of cell–nanostructure interactions. [Copyright &y& Elsevier]