Synthesis of Porous Carbon Nanofibers on Catalysts Fabricated by the Mechanochemical Method

A mechanochemical method for fabrication of catalysts for vapor-phase deposition of porous carbon nanofibers from acetylene is suggested.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 6, 2005, pp. 945–951.Original Russian Text Copyright © 2005 by Melezhik, Sementsov, Yanchenko.     

On Entire Solutions of a Class of Second-Order Algebraic Differential Equations

Mathematical Notes - For second-order algebraic differential equations which have an explicit linear part, we describe all their possible solutions that are entire functions of finite order.     

Kolmogorov Widths of the Nikol’skii–Besov Classes of Periodic Functions of Many Variables in the Space of Quasicontinuous Functions

Ukrainian Mathematical Journal - We obtain order estimates for the M-dimensional Kolmogorov widths of the Nikol’skii–Besov classes of periodic functions of many variables with...     

Synthesis,structure, and photocatalytic properties of Zn<Subscript>1–<Emphasis Type="Italic">x</Emphasis></Subscript>Cu<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>O: CuO composites with various morphologies of aggregates

Using mixed copper zinc carboxylates as precursors, Zn_1–x Cu _x O: CuO composite materials with various morphologies and microstructures of aggregates were synthesized. Their structural, optical, and photocatalytic characteristics were determined.     

Synthesis and native defectivity of Zn1−x V x O (0 ≤ x ≤ 0.03) photocatalysts

Nanodisperse solid solutions Zn_1?x V _x O (0 ≤ x ≤ 0.03) with high numbers of defects in an oxygen sublattice are synthesized via the precursor technique. ESR analysis reveals that V _O ⁺ oxygen vacancies are the main defects of the oxygen sublattice in the Zn_1?x V _x O structure. The Zn_1?x V _x O (0 < x ≤ 0.15) solid solutions exhibit high photocatalytic activity during hydroquinone oxidation in water upon irradiation with UV and visible light.     

Synthesis and photocatalytic activity of Ti[1 ? x]VxO[2 ? y]Cy whiskers in hydroquinone oxidation in aqueous solutions

Ti_1−x V _x O_2−y C _y (0 ≤ x ≤ 0.10 and x = 0.50) whiskers having the anatase structure were synthesized via thermolysis of vanadium-doped titanium glycolate of composition Ti_1−x V _x (OCH₂CH₂O)₂ (0 ≤ x ≤ 0.10 and x = 0.50). The starting reagents used to prepare Ti_1−x V _x (OCH₂CH₂O)₂ were mixtures of coprecipitated titanium and vanadyl hydroxides, which were heated in ethylene glycol at T ≤ 200°C: (1 − x)TiO(OH)₂ + xVO(OH)₂ + 2HOCH₂CH₂OH = Ti_1−x V _x (OCH₂CH₂O)₂ + 3H₂O↑. Thermolysis of vanadium-doped titanium glycolate in various gas media over a wide range of temperatures is useful to prepare titania samples doped with both vanadium and carbon to form a phase of the general composition Ti_{1 − x} V _x O_{2 − y} C _y whiskers prepared by thermolyzing Ti_{1 − x} V _x (OCH₂CH₂O)₂ in air at 450°C were found to have a high photocatalytic activity in hydroquinone oxidation in aqueous solutions irradiated in the UV spectral range; the photocatalyst’s activity increases with increasing vanadium concentration. When hydroquinone was irradiated in the blue, the maximal catalytic activity was discovered in a sample of composition Ti_0.50V_0.50O_2−y C _y . Quantum-chemical calculations support experimental data that the double doping of titania (Ti_1−x V _x O_2−y C _y ) enhances its photocatalytic activity compared to undoped anatase or anatase doped in one sublattice: Ti_1−x V _x O₂ and TiO_2−y C _y .     

Fractal structure of fullerite

We have obtained macroscopic fractal aggregates of fullerite ranging in size from 100 to 400 μm. The fractal structure of fullerite is formed by microscopic (30–100 nm) fullerite crystals in the presence of a temperature gradient under conditions of diffusion-limited aggregation. Pis’ma Zh. éksp. Teor. Fiz. 67, No. 9, 684–685 (10 May 1998)