Synthesis, characterization and growth mechanism of flower-like vanadium carbide hierarchical nanocrystals

Abstract

Novel flower-like vanadium carbide (V 8 C 7 ) hierarchical nanocrystals have been successfully synthesized in a large-scale hydrothermal process using a mixture of diethanolamine (HN(C 2 H 4 OH) 2 , DEA) and V 2 O 5 powder. The products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), selected-area electron diffraction (SAED) and energy-dispersive spectra (EDS). The results showed that flower-like products consist of very thin sheets with an average thickness of 10 nm and the nanosheets were a uniform single-crystalline V 8 C 7 phase. It was found that reaction temperature and type of capping molecules have a crucial influence on the morphology of the products. A possible growth mechanism of the flower-like V 8 C 7 hierarchical nanocrystals is proposed and discussed.

Influence of Vanadium-Chromium Carbide on the Microstructure of Reinforced FeCrV15 Hardfacing during Laser Cladding Deposit

“…4c, and d. This is in agreement with Günther and Bergmann (Günther and Bergmann, 2020), Primarily, the vanadium carbide is indicated by the dark star-ower-like structure (Ma et al, 2010) and shbone or rod-like solidi cation( Fig. 3c and d) in the micrograph, position 2 and 3.…”

Synthesis of H2V3O8/Reduced Graphene Oxide Composite as a Promising Cathode Material for Lithium‐Ion Batteries

“…The V 2p 3/2 (Figure 6 b) core level peak can be divided into three constituents, corresponding to V 5 + (517.8 eV), V 4 + (516.2 eV), [11] and the VÀC bond (516.9 eV). [28] Quantification of the peak areas shows that the surface ratio of V 5 + /V 4 + is approximately two, which is very close to the chemical stoichiometry of V 5 + /V 4 + in H 2 V 3 O 8 . The C 1s XPS peak of graphene oxide (Figure 6 c) contains four typical components corresponding to the carbon atoms in functional groups: the nonoxygenated C ring (284.7 eV), and the hydroxyl or epoxide (286.4 eV), carbonyl (287.1 eV), and carboxyl (288.6 eV) groups.…”

“…After the hydrothermal treatment (Figure 6 d), the relative intensities of the three oxygen-containing functional groups decrease markedly, suggesting that the graphene oxide is reduced successfully. The C 1s peak at 282.3 eV is attributed to the VÀC bond, [28] which indicates that the H 2 V 3 O 8 nanowires are anchored on the RGO sheets through a VÀC linkage. For the pristine H 2 V 3 O 8 , there are three reduction peaks in the first scan, which correspond to a series of structural transitions during the Li + intercalation process, as described in previous reports.…”

VS4 Nanoparticles Anchored on Graphene Sheets as a High‐Rate and Stable Electrode Material for Sodium Ion Batteries

“…The V 2p X‐ray photoelectron spectroscopy (XPS) of the material showed two peaks at 517.3 and 524.3 eV, which were ascribed to the 2p 3/2 and 2p 1/2 components of V 4+ , respectively (Figure d) . Two other peaks at 513.9 and 521.5 eV corresponded to the V−C bond, which indicated that the VS 4 nanoparticles were anchored on the graphene surface through a V−C bond, which was in agreement with the Raman scattering results.…”