博文

目前显示的是 十月, 2016的博文

Preparing Ammonium Paratungstate from Worn-Out Tungsten Oxide

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Warn-out tungsten oxide including tungsten trioxide and blue tungsten oxide ect. which have been scrapped, and substandard thus must be reworked. This warn-out tungsten oxide which can not directly be used in tungsten smelting or other industries can be recycling. In this paper we will present a method for recovering ammonium paratungstate from warn-out tungsten oxide. 1. Handling the raw material Screen the warn-out tungsten oxide by a 60~80 mesh sieve to remove caking tungsten oxide and mechanical inclusions; then the grinding caking tungsten oxide and also screen it; 2. Autoclaving with ammonia for preparing ammonium tungstate solution 1) Dilute the concentrated ammonia in deionized water or use water to absorb liquid ammonia, get ammonia with concentrate of 8~20%; and then formulating the slurry with stirring at the ratio that weight of tungsten oxide: volume of ammonia is 150~350g/L; 2) Add hydrogen peroxide when the material contains blue tungsten oxide, compress the k

Ammonium Paratungstate Preparing Ultrafine Cesium-tungsten Oxide Powder

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Cesium is a golden yellow metal, low melting point active metal, easily oxidized in air and can react violently with water to produce hydrogen and even explode. There is no elemental form of cesium in nature, cesium minimal distribution in the ocean in the form of cesium salt. Cesium tungsten bronze is widely used because of its low resistance, excellent visible light transmittance, near-infrared shielding properties. Also it is widely used in preparing conductive thin film, since being the glass transparent insulation coating as insulating agent, it has excellent properties like low resistance, excellent visible light transmittance and near-infrared shielding performance. The article provides a method that using ammonium paratungstate and cesium nitrate as raw materials to produce Cesium-tungsten oxide ultrafine powder, the specific steps are as follows: 1. Weighing the cesium nitrate, ammonium paratungstate by the molar ratio of Cs/W being 1: (1.5 to 2.8), and adding chelating agent

Tungsten Oxide Thin Film Electrode Cyclic Voltammetry

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Nano semiconductor material used as photocatalyst to photolysis water has gained well efficiency. TiO 2  has high catalytic activity and stability is widely used as a kind of photocatalytic material. But its band gap is big (~3.2 eV), it can only be motivated by ultraviolet with short wave length, its light transaction efficiency is low (~4%). Tungsten oxide is an indirect band series transition semiconductor material. Compared to TiO 2 , it has narrow band gap (2.5~3.0 eV), the relevant absorbing wave length is 410~500nm and well photoelectric responsive property in visible light area. Tungsten oxide thin film electrode preparation method: Raw material: FTO glass; tungstic acid; hydrogen peroxide; acetone. (1) Be ready with clean FTO glass as the substrate of depositing WO 3 . Cut FTO glass into 1.2cm*2.5cm pieces and clean it by ultrasound and ultraviolet. The clean and flatness of FTO substrate has big effect on adhesive force and uniformity of thin film electrode. So

Tungsten Oxide in Inverted Polymer Solar Cell

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Interest in solar cells to capture sunlight and generate electricity is increasing due to oil energy crisis and rising concerns over global climate change. Inorganic solar cells can yield high power conversion efficiency but the expensive fabrication process makes them infeasible in common use. Instead, polymer solar cells PSCs are a good candidate because semiconducting polymers can be dissolved in common solvents and printed like inks so that economical roll-in-roll fabrication process can be realized. The photoactive layer composed of electron donating and accepting materials absorbs light and generates excitons. Then electrons and holes can be efficiently separated from each other due to the nanometer-scale interpenetrating network of electron donor and acceptor within the whole photoactive layer.3 However, a simple structure that sandwiched the photoactive layer between two electrodes anode and cathode is not perfect enough. The low efficiency of charge collection at the interfac

Tungsten Oxide as Alternative Energy Source

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While the global climate heats up, so does the conversation on sustainability and the need for alternative energy and fuel resources. Dr. Robert Mayanovic, assistant department head of physics, astronomy, and materials science at Missouri State University, brings new hope to the topic as he has helped to discover a porous metal-oxide that could potentially be used as an alternative to traditional energy and fuel resources. “Basically, we are looking for ways to develop materials that can be used in the future to harness conventional or alternate energy sources in a more sustainable fashion than what materials offer today,” said Mayanovic. “The first phase of the project is to test the stability of the materials in extreme environments.” Using a large x-ray machine called a synchrotron, which allows the materials to be probed down to the atomic level, Mayanovic and colleagues Dr. Sonal Dey of Colleges of Nanoscale Science and Engineering, and Dr. Ridwan Sakidja, associate p

Defect State Nano Structure Tungsten Oxide Catalyst Is Invented

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USTC(University of Science and Technology of China) recently announced that professor Xiong Yujie research group designed a kind of tungsten oxide nano structure in defect state based on inorganic solid accurate preparation of chemical and use crystalline defect project. Under broad spectrum illumination, it shows fine oxidation coupling catalytic property which is expected to realize low cost and low-energy organic chemical technology. Tungsten oxide has good photocatalytic property due to its special structure, it has already been used as varies of catalyst and also other industrial fields.  Most of catalytic reaction is based on the application of precious metal oxide and motivated by burning of petroleum and coal. It has disadvantages of high cost and high energy consuming. Compared to precious metal catalyst, metal oxide has benefits of low cost. However, it shows shortcomings in oxygen molecular system which can not capture solar energy and pass it into oxygen molecular.