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Abstract: Large-scale uniform nutlike ZnO microcrystals are successfully synthesized via a facile hydrothermal process at low temperature (95 °C). The structure and morphology of the ZnO products are characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The results reveal that the as-prepared ZnO products have average length of 2.2 µm and diameter of 1.8 µm, possessing a single crystal wurtzite structure. The possible formation mechanism of nutlike microcrystals is proposed. The samples exhibit excellent ethanol sensing properties at the operating temperature of 250 °C detecting ethanol as low as 1 ppm. [Copyright &y& Elsevier]

Lithium chloride (LiCl)-loaded 3D cubic mesoporous silica KIT-6 (LiCl-KIT-6) composites were prepared as resistance-type humidity-sensitive materials. The structures of the resultant composites were characterized by X-ray diffraction, N 2 adsorption–desorption, and transmission electron microscopy. The humidity sensors based on LiCl-KIT-6 composites were fabricated and the sensing properties were investigated. Results indicate the uniform pore distribution of KIT-6 contributes to the rapid hydrone transport in mesoporous channels. The impedance of optimized 3 wt% LiCl-KIT-6 sensor changed by more than three orders of magnitude over the relative humidity range of 11–95%. The response and recovery times of the sensor were 15 s and 28 s, respectively. Finally, the complex impedance method was used to analyze the humidity sensing mechanism of the sensor based on LiCl-KIT-6. [ABSTRACT FROM AUTHOR]

Abstract: Uniaxially aligned Ba0.8Sr0.2TiO3 (BST) nanofiber arrays were fabricated via electrospinning combined with annealing. A specially designed collector composed of two paralleled aluminum electrodes and an insulative substrate were used in the electrospinning process. The morphology and structure of the resultant arrays were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The SEM shows well uniaxial arrangement and the diameters before (300–500nm) and after (100nm) calcination. XRD shows well-defined perovskite crystal structure of the as-synthesized arrays. The humidity sensor based on the as-synthesized arrays exhibited a rapid response-recovery property at room temperature. The possible sensing mechanism was proposed. [Copyright &y& Elsevier]