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The NiO nanoflowers were prepared by a facile surfactant assisted hydrothermal method using Ni(NO 3 ) 2 –6H 2 O or NiCl 2 –6H 2 O as precursor compound. The microstructure of the samples was characterized by SEM and XRD. The gas sensing properties of the NiO nanoflowers toward ethanol was also investigated. The results show that surfactant plays a key role in the synthesis of flower-like NiO. The NiO nanoflowers show excellent sensing performances to ethanol gas. This morphology holds substantial promise for applying NiO as a potential gas sensing material for future sensor application. [ABSTRACT FROM AUTHOR]

In this paper, WO 3 ·H 2 O with different nanostructures from 0D to 3D were successfully synthesized via a simple yet cost-effective hydrothermal method with the assistance of surfactants. The structures and morphologies of products were investigated by XRD and SEM. Besides, we systematically explained the evolution process and formation mechanisms of different WO 3 ·H 2 O morphologies. It is noted that both the kinds and amounts of surfactants strongly affect the formation of WO 3 ·H 2 O crystals, as reflected in the tailoring of WO 3 ·H 2 O morphologies. Furthermore, the gas sensing performance of the as-prepared samples towards methanol was also investigated. 3D flower-like hierarchical architecture displayed outstanding response to target gas among the four samples. We hoped our results could be of great benefit to further investigations of synthesizing different dimensional WO 3 ·H 2 O nanostructures and their gas sensing applications. [ABSTRACT FROM AUTHOR]

Hollow spheres are usually fabricated by hard template methods or soft template methods with soft surfactants, which is quiet tedious and time-consuming. In this paper, NiO hollow spheres with fluffy surface were successfully synthesized by a facile hydrothermal method and subsequent calcination, where bubbles acted as the template. NiO hollow spheres exhibited excellent gas sensing performances, which results from its hollow structure and high specific surface area. In addition, a possible evolution mechanism of NiO hollow spheres was proposed based on experimental results. [ABSTRACT FROM AUTHOR]

Abstract: WO3 H2O with different morphologies were synthesized through hydrothermal method by adding different surfactants. The effect of surfactants on tailing morphology was investigated through XRD and SEM analyses in detail and the possible formation mechanism was discussed. Furthermore, the gas-sensing performances of obtained samples to ethanol were investigated. The results revealed that the WO3 H2O with the hierarchical architectures assembled by nanosheets shows the highest response to ethanol among four kinds of the nanostructures WO3. These results on the preparation, mechanism and gas sensing properties of WO3 H2O nanostructures hold great potential for the syntheses of oxide materials with novel nanostructures and their applications. [Copyright &y& Elsevier]

Monoclinic scheelite BiVO 4 nanoplates have been prepared via a facile hydrothermal method with monoethanolamine as a surfactant. The obtained BiVO 4 nanoplates were characterized by XRD, SEM, Raman microscope and N 2 adsorption-desorption analysis. The BiVO 4 prepared with MEA is monoclinic scheelite plates which is composed of nanocrystallite with the average size of 100 nm. The sensors based on BiVO 4 nanoplates show good sensitivity to alcohols gases, especially to n-butanol. The sensitivity to 100 ppm n-butanol gas is 61.6 at 260 °C, and the sensors exhibit low sensitivity to xylene, formaldehyde and toluene. The BiVO 4 nanoplates could be a promising candidate for high selectivity and high sensitivity n-butanol gas-sening materials. [ABSTRACT FROM AUTHOR]