Orientation Controllable Growth of MoO₃ Nanoflakes: Micro-Raman, Field Emission, and Birefringence Properties

Abstract

A simple but effective way to control the orientational arrangement of MoO3 nanoflakes is presented, which offers an opportunity to investigate the anisotropic properties of different crystallographic faces. Their electrical and optical properties are investigated. According to the polarized micro-Raman spectra, oxygen vacancies preferred to be located at the sharp side edges of the lamella, which might play an important role in the catalytic properties of samples. Ascribing to the unique structural geometry and the oxygen-defects-induced reduction of the work function, the electron field emission properties of the samples show that the erect MoO3 nanoflakes are potential candidates for the cold-cathode-based electronics. Furthermore, strong optical birefringence properties of samples are also first observed.

Synthesis, structural and vibrational properties of microcrystalline RbNd(MoO4)2

“…The narrowest (FWHM is 6.4 cm À 1 ) and intensive line is detected at 936 cm À 1 . This line can be considered as an analog of Mo¼O stretch line of a-MoO 3 crystals (995 cm À 1 ) [24][25][26]. Two lines at 802 and 864 cm À 1 with FWHM of 17 and 20 cm À 1 , respectively, are evidently wider.…”

Binder effect on the catalytic activity of MoO3 bulk catalyst reduced by H2 for n-heptane hydroisomerization

“…The highest catalytic activity for hydroisomerization was obtained 41 with the alumina-based bulk catalyst, although the silica-based bulk catalyst showed lower amounts of 42 cracking products and a higher selectivity to dimethylpentanes. The bulk catalysts resulted more active 43 than MoO 3 powder. The results indicate that the acid-base properties of the binder have a desirable effect 44 on the acidity of the molybdenum trioxide powder as hydroisomerization catalyst.…”

Sublimation growth and vibrational microspectrometry of α-MoO3 single crystals

“…Presently four polymorph modifications are known for molybdenum trioxide, orthorhombic a-MoO 3 [6,7], monoclinic b-MoO 3 [8], high-pressure monoclinic MoO 3 -II [9] and hexagonal h-MoO 3 [10,11]. Phase composition, micromorphology and defect structure of molybdenum oxides in thin film, micro-and nanocrystalline forms are strongly dependent on the technological conditions used for synthesis [3][4][5]7,[12][13][14][15][16][17][18]. Orthorhombic a-MoO 3 , space group Pbmn, with unique layered structure is a stable polymorph modification at normal conditions [6,7].…”

“…Orthorhombic a-MoO 3 , space group Pbmn, with unique layered structure is a stable polymorph modification at normal conditions [6,7]. Crystal structure of a-MoO 3 is formed by a stock of bilayers of distorted MoO 6 octahedra that defines strong anisotropy of physical properties and platelet equilibrium shape of a-MoO 3 crystals [7,12,16,[18][19][20][21][22].…”