Arginine-Assisted Hydrothermal Synthesis of Urchin-like Nb₂O₅ Nanostructures Composed of Nanowires and Their Application in Cyclohexanone Ammoximation

Abstract

Urchin-like Nb2O5 nanostructures have been successfully synthesized by a novel and simple l-arginine-assisted hydrothermal method. They are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), nitrogen adsorption–desorption isotherms, thermogravimetric and differential thermal analysis (TG-DTA), and Fourier transform infrared spectroscopy (FT-IR). The results show that the urchin-like nanostructures are composed of nanowires with diameter less than 15 nm and possess a high specific surface area of 249.9 m2·g–1. Urchin-like Nb2O5 nanostructures have been used for the first time as a novel catalyst instead of conventional titanosilicate in the liquid-phase ammoximation of cyclohexanone. The as-prepared urchin-like Nb2O5 nanostructures exhibit high catalytic activity in cyclohexanone ammoximation. Under the optimal reaction conditions, the conversion of cyclohexanone and selectivity of oxime are as high as 98.0% and 88.9%, respectively. Finally, a possible formation mechanism of urchin-like Nb2O5 nanostructures is proposed.

Efficient synthesis of niobium pentoxide nanowires and application in ethanolysis of furfuryl alcohol

“…18-0911). 28 In Fig. 1(a), the (001), (002) peak intensities are in accordance with the standard PDF card, and the other peaks are weak, which shows that the compound has a special morphology.…”

Facile route for C–N/Nb2O5 nanonet synthesis based on 2-methylimidazole for visible-light driven photocatalytic degradation of Rhodamine B

“…Another strong peak appearing at 1633 cm −1 was attributed to the bending vibrations of hydroxyl groups in H 2 O molecules. 24 These findings indicated that imidazole molecules were present on the surface of the Nb 2 O 5 –Hmim (black, Fig. 3 ).…”

“…The Nb 2 O 5 nanonets were synthesized by using a hydrothermal method as described previously with some modifications. 24 In a typical synthesis, a 2 mmol niobium oxalate was dissolved in 25 mL of a co-solvent containing 15 mL deionized water and 10 mL absolute ethanol at 60 °C under stirring for 10 min to form solution A. To prepare solution B, a 1 mmol Hmim was dissolved in 5 mL deionized water with continuously stirring for 5 min.…”

Preparation of Hollow Niobium Oxide Nanospheres with Enhanced Catalytic Activity for Oxidative Desulfurization

“…The hollow niobium oxide nanosphere catalyst has a larger specific surface area, which usually provides more active sites for catalytic reactions. Additionally, the hierarchical porous structure can facilitate the diffusion of reactant molecules, making them more accessible to the active site [ 21 ]. Table 2 shows the oxidative desulfurization of DBT over various metal oxide catalysts using H 2 O 2 as the oxidant.…”