Facile Microwave-Refluxing Synthesis and Catalytic Properties of Vanadium Pentoxide Nanomaterials

Vanadium pentoxide nanomaterials were prepared by a facile microwave-assisted refluxing reaction of VOSO 4 and (NH 4 ) 2 S 2 O 8 solutions under atmospheric pressure at 100 °C for 1 h. The synthesized products were characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and Brunauer–Emmett–Teller surface area measurements. The catalytic oxidation and photocatalytic activities of the synthesized V 2 O 5 were evaluated by oxidative cyanation of N, N -dimethylaniline in methanol and photodegradation of N -nitrosodimethylamine (NDMA) in aqueous solution, respectively. V 2 O 5 · x H 2 O nanofibers were formed when VOSO 4 and (NH 4 ) 2 S 2 O 8 solutions were irradiated with microwaves under reflux conditions at 100 °C within 1 h. Nanostructured V 2 O 5 was synthesized by calcining V 2 O 5 · x H 2 O at 280 °C for 12 h. The conversion of N, N -dimethylaniline to N -methyl- N -phenylcyanamide increased with an increase in the amount of V 2 O 5 catalyst. As the amount of synthesized V 2 O 5 increased from 10 to 15 mg, the conversion of N, N -dimethylaniline to N -methyl- N -phenylcyanamide reached 100%, but the selectivity decreased from 100% to 96%. N -methyl- N -phenylformamide was formed as a byproduct because of use of excess V 2 O 5 . The as-synthesized V 2 O 5 nanomaterials showed comparable photocatalytic performance with commercial TiO 2 (P-25) for the degradation of N -nitrosodimethylamine to NO 3 – in water. This work provides a facile synthesis method of nanosized V 2 O 5 · x H 2 O and V 2 O 5 with excellent catalytic activities.