Crystallizing Vanadium Pentoxide Nanostructures in the Solid‐State Using Modified Block Copolymer and Chitosan Complexes

Abstract

A systematic study of the synthesis of V2O5nanostructured materials using macromolecular PS-co-4-PVP·(VCl3)yand chitosan·(VCl3)ycomplexes is presented. It is demonstrated that various coordination degrees of the metal into the polymeric chain specifically influence the product formation after pyrolysis. PS-co-4-PVP·(VCl3)yand chitosan·(VCl3)ycomplexes were prepared by simple coordination reaction of VCl3with the respective polymer in molar ratios 1 : 1, 1 : 5, and 1 : 10 metal/polymer and characterized by elemental analysis, IR spectroscopy, and TGA/DSC analysis. Solid-state thermolysis of these precursors at several temperatures under air results in nanostructured V2O5using all precursors. The size and shape of the nanostructured V2O5depend on the nature of the polymer. For the chitosan·(VCl3)yprecursors sub-10 nm nanocrystals are formed. The calcination process, involved in the preparation method, produces V2O5with photoluminescence in the visible light region, suggesting the possible application in oxygen sensing devices.

Solid-state synthesis of LnOCl/Ln2O3 (Ln = Eu, Nd) by using chitosan and PS-co-P4VP as polymeric supports

“…Similarly to LnOCl materials, the synthesis of Ln 2 O 3 is usually achieved by using solution methods [17,18] , being the solid-state routes limited to a solution-solid state route based on a coordination polymer created by the combination of a lanthanide metal and amino acids [8] . Our group has been recently studying different solid-sate routes to nanostructured metal oxides such as V 2 O 5 [19] , Fe 2 O 3 [20] , ZnO [21] , SnO 2 [21] as well some metal as Pt [22] and mixtures as Pd/PdO [23] . These solid-state routes are based on heating an appropriate macromolecular complex, which has been previously created by mixing a polymeric support and metallic salt.…”

“…without any solvent evaporation steps, which preclude the particle agglomeration or tedious solvent evaporation procedures [7][8][9][10][11][12][13][14][15][16][17][18] . The macromolecular complexes Chitosan•(LnCl 3 ) and PS-co-P4VP•(LnCl 3 ), Ln = Eu and Nd; PS-co-P4VP = poly(4-vinylpyridine)-co-polystyrene) were prepared according to a previous synthetic methodology described by us for other macromolecular precursors [19][20][21][22][23] .…”

Enhanced photocatalytic hydrogen evolution by novel Nb-doped SnO2/V2O5 heteronanostructures under visible light with simultaneous basic red 46 dye degradation

“…As shown in Figure 6(b), the estimated E g (3.48 eV) for SV heteronanostructure is less than that of the SnO 2 nanotubes (3.79 eV) reported in previous study [6]. Also, V 2 O 5 is an n-type semiconductor with a narrow band gap in the range of 2-2.6 eV [35]. When the SnO 2 nanotube is coupled with the V 2 O 5 nanoparticles, the photogenerated electrons can easily migrate from SnO 2 to V 2 O 5 .…”

Role of Polyvinylpyrrolidone (PVP) on Controlling the Structural, Optical, and Electrical Properties of Vanadium Pentoxide (V2O5) Nanoparticles

“…Peak around 400 nm is near band emission peak attributed to radiative recombination of free excitons from the bottom of the V 3d conduction band to the top of the O 2p valance band. [42][43][44] Also, the recombination of excitons from V 3d splits off conduction band to the top of O 2p valance band, which causes the PL spectrum to peak at around 450 nm. [45] Peak around 560 nm belongs to a defectrelated peak, oxygen vacancies, which is derived from the lowest defect donor band to O 2p valance band in V 2 O 5 nanoparticles.…”