Abstract

Pyrolysis of molecular precursors containing vanadium organometallic and cyclic phosphazene affords mixtures of nanostructured vanadium oxides and pyrophosphates. The products from the molecular precursor [N 3P 3(OC 6H 5) 5OC 5H 4N·Cp 2VCl][PF 6], and of the mixtures Cp 2VCl 2/N 3P 3(OC 6H 4CHO) 6 and Cp 2VCl 2/[NP(O 2C 12H 8)] 3 in several relationships 1:1, 1:3, 1:5 and 1:10, pyrolyzed under air and at 400 °C and 600 °C, give mixtures mainly V 2O 5 and VO(PO 3) 2. Varied morphologies depending on the molecular or mixture precursors and of the temperature used were observed. Nanowires with diameters of approximate 40 nm were observed for the 1:5 Cp 2VCl 2/[NP(O 2C 12H 8)] 3 mixture pyrolyzed at 400 °C, while the same mixture pyrolyzed at 600 °C, affords xerogels of V 2O 5. The products were characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), infra-red (IR) spectroscopy and X-ray diffraction (XRD). The preparation method constitutes a novel one-pot solid-state way to nanostructured materials with potential applications both in oxidative dehydrogenation of light hydrocarbons with V 2O 5, as well as alkenes oxidations with VO(PO 3) 2. © 2011 Springer Science+Business Media, LLC.