XPS study of V_1.67Ti_0.33O_5±δ·nH₂O xerogels intercalated with hydroquinone

Abstract

Layered nanocomposites of V1.67Ti0.33O 5±δ ·nH2O gels are synthesized by using sol-gel technology. Then an aqueous solution of hydroquinone (HQ) was mixed with the formed gel in molar ratio 0.33 : 1 and 0.17 : 1 respectively. In this way the V1.67Ti0.33O 5±δ ·nH2O / 2HQ and V1.67Ti0.33O 5±δ ·nH2O / HQ gels were synthesized. The valences of vanadium and titanium ions in the investigated compounds are studied by means of X-ray photoelectron spectroscopy (XPS) before and after etching the samples with Ar + ions for 15 min (3 keV, current density 10 µA cm −2 ). XPS analysis results show that independent of the hydroquinone intercalation degree (one or two hydroquinone) and Ar + ion etching the ions of titanium are in stable 4+ states. Vanadium ions in all cases (one or two hydroquinone, before and after etching) are in V 3+ , V 4+ , and V 5+ states. The increase in quantity of hydroquinone in the samples leads to higher concentration of V 3+ and V 4+ ions. The concentrations of lower valence vanadium ions increase after Ar + ion etching of the samples.

One-Dimensional Vanadium Nitride Nanofibers Fabricated by Electrospinning for Supercapacitors

“…7b). The reported binding energies for V 3+ , V 4+ and V 5+ species are three Gaussian distributions centered at 515.6, 516.5, and 517.3 eV, respectively, with the statistical deviation W BE = 0.25 eV [48]. The binder energy of 513.6 eV can be ascribed to VN.…”

Mesoporous Coaxial Titanium Nitride-Vanadium Nitride Fibers of Core–shell Structures for High-Performance Supercapacitors

“…The reported binding energies for V 3+ , V 4+ and V 5+ species were three Gaussian distributions centered at 515.6, 516.5, and 517.3 eV, respectively, with the statistical deviation W BE = 0.25 eV. 42 The XPS spectrum of the surface of TiN-VN fibers was exhibited in Figure 8. After cycling, the peaks of oxygen, titanium and vanadium were obviously increased.…”

XPS Study of Sol-Gel Synthesized Vanadium-Titanium-Hydroquinone Oxide Bronze Films

“…The O 1s peak of the same xerogel consists of three components with a BE of ~ 530 eV, ~ 531 eV and ~ 533 eV, which correspond to O 2-ions connected with vanadium and titanium ions, hydroxyl groups (OH) -and oxygen in water molecules, respectively [22,[28][29][30]. Similar XPS spectra were 202 Volume 54 observed in various hydrated compounds based on vanadium pentoxide [4,20,31,32]. After thermal treatment at 580 K, as described in the experimental section of this study, the XPS spectrum of the vanadium-oxygen region changes radically.…”

“…With the simple sol-gel method, it is possible to produce many nanocomposites by embedding various ions and radicals between the layers [3][4][5][6][7]. Certain physical properties of the layered nanocomposites of V 1.67 Me 0.33 O 5±δ •nH 2 O (Me = Mo or Ti) xerogels intercalated with hydroquinone (chemical formula: C 6 H 4 (OH) 2 , hereinafter referred to as HQ) and poly(vinyl alcohol) (PVA) were first described in Ref.…”