Pulsed Laser-Deposited TiO2-based Films: Synthesis, Electronic Structure and Photocatalytic Activity

Active under visible light, photocatalysts based on doped titania were obtained via pulsed laser deposition (PLD) method. To find out the crystalline structure, optical properties, and electronic structure, the following techniques such as X-ray diffraction, electronic spectroscopy, electrical conductivity measurements, and X-ray photoelectron spectroscopy (XPS) are used. Photocatalytic activity is monitored by applying the photoreduction of dichromate ions under UV and visible light. The influence of zirconium ions and its content and synthesis conditions on the efficiency of nitrogen incorporation into titania structure that, in turn, determines the electronic structure and photocatalytic ability of the semiconductive materials are discussed. A substitutional nitrogen (Ti–N) rather than an interstitial one (Ti–O–N) is mainly responsible for the observed photoactivity. It is pointed that substitutional nitrogen is responsible for bandgap narrowing or formation of intragap localized states within semiconductor bandgap. The bandgap energy values are sharply decreased, while the relative intensity of substitutional nitrogen XPS peaks is increased. Pulsed laser synthesis of TiO2 films in N2/CH4 atmosphere not only leads to nitrogen incorporation but also to the formation of defects including oxygen vacancies and Ti3+ states which are all contributing to light absorption. An appropriate ratio of gas mixture, optimum zirconia content, suitable pressure, and temperature during synthesis was found for the synthesis of highly active semiconductive films. The highest photocatalytic conversion yields are obtained for nitrogen-doped 10% ZrO2/TiO2 synthesized in N2:CH4 = 5:1 at 100 Pa and at 450°C under both UV and visible light

Modification of All-Union Unified Method for Determination the Content of Tanning Substances in Extracts of Bark of Conifers

Кожевенно-технологические свойства растительных дубителей определяются по показателю доброкачественности. В качестве стандартного метода для определения доброкачественности дубильных материалов принят всесоюзный единый метод, в основу которого положено свойство таннидов адсорбироваться гольевым порошком. Поскольку производство гольевого порошка прекращено, вопрос о его замене остается открытым. В данной статье сравниваются результаты ряда методов, с помощью которых возможно определять доброкачественность дубителей. Показана возможность замены гольевого порошка на коллаген при определении таннидов всесоюзным единым методом в нашей модификацииTechnological properties of plant tanning extracts are defined in terms of their quality. Standard method for determining the quality of tanning materials adopted by the all-Union unified method is based on the property of leather powder to adsorb tannins. Since the production of leather a powder was terminated it is necessary to find the alternative method. Different methods of determination of tanning matter quality were compared. The possibility to use the collagen instead of leather powder for evaluation of quality of tannins was shown experimentall

Modification of All-Union Unified Method for Determination the Content of Tanning Substances in Extracts of Bark of Conifers

Кожевенно-технологические свойства растительных дубителей определяются по показателю доброкачественности. В качестве стандартного метода для определения доброкачественности дубильных материалов принят всесоюзный единый метод, в основу которого положено свойство таннидов адсорбироваться гольевым порошком. Поскольку производство гольевого порошка прекращено, вопрос о его замене остается открытым. В данной статье сравниваются результаты ряда методов, с помощью которых возможно определять доброкачественность дубителей. Показана возможность замены гольевого порошка на коллаген при определении таннидов всесоюзным единым методом в нашей модификацииTechnological properties of plant tanning extracts are defined in terms of their quality. Standard method for determining the quality of tanning materials adopted by the all-Union unified method is based on the property of leather powder to adsorb tannins. Since the production of leather a powder was terminated it is necessary to find the alternative method. Different methods of determination of tanning matter quality were compared. The possibility to use the collagen instead of leather powder for evaluation of quality of tannins was shown experimentall

Modelling of the Process of Extraction of the Pine Bark of Water-Alkaline Solution

Optimization of process extraction pine bark of water-alkaline solution, by the regression equation. Shows the adequacy of this process, providing a mathematical model and parametric identification of the model. Defined and presented the technological parameters of extraction and characterization of the pine bark extract, received in the normal modeОптимизирован процесс экстракции коры сосны водно-щелочным раствором, установлено уравнение регрессии. Показана адекватность данного процесса, представлена математическая модель и параметрическая идентификация данной модели. Определены технологические параметры экстракции и дана характеристика экстракта коры сосны, полученного в оптимальном режим

Modelling of the Process of Extraction of the Pine Bark of Water-Alkaline Solution

Optimization of process extraction pine bark of water-alkaline solution, by the regression equation. Shows the adequacy of this process, providing a mathematical model and parametric identification of the model. Defined and presented the technological parameters of extraction and characterization of the pine bark extract, received in the normal modeОптимизирован процесс экстракции коры сосны водно-щелочным раствором, установлено уравнение регрессии. Показана адекватность данного процесса, представлена математическая модель и параметрическая идентификация данной модели. Определены технологические параметры экстракции и дана характеристика экстракта коры сосны, полученного в оптимальном режим

TiO 2 /ZrO 2 THIN FILMS SYNTHESIZED BY PLD IN LOW PRESSURE N-, C-AND/OR O-CONTAINING GASES: STRUCTURAL, OPTICAL AND PHOTOCATALYTIC PROPERTIES

Doped TiO 2 /ZrO 2 films were obtained by Pulsed Laser Deposition method under different synthesis conditions. The onset of absorption spectra was red shifted for the films obtained in N 2 containing gas mixtures, while a broad absorption in visible was observed in the case of films deposited in CH 4 atmosphere. The presence of O-Ti-N bonds revealed by XPS corresponded to the highest photocatalytic performance. XPS spectra of the samples obtained in N 2 /CH 4 gas mixtures evidenced a more effective incorporation of nitrogen in the structure due to oxygen deficiency. Nevertheless, no atomic carbon presence in the TiO 2 /ZrO 2 structures has been detected

Tio2/zro2 thin films synthesized by pld in low pressure n-, c- and/or o-containing gases: structural, optical and photocatalytic properties

Doped TiO2/ZrO2 films were obtained by Pulsed Laser Deposition method under different synthesis conditions. The onset of absorption spectra was red shifted for the films obtained in N-2 containing gas mixtures, while a broad absorption in visible was observed in the case of films deposited in CH4 atmosphere. The presence of O-Ti-N bonds revealed by XPS corresponded to the highest photocatalytic performance. XPS spectra of the samples obtained in N-2/CH4 gas mixtures evidenced a more effective incorporation of nitrogen in the structure due to oxygen deficiency. Nevertheless, no atomic carbon presence in the TiO2/ZrO2 structures has been detected