Tungsten Oxide

The study found that adding the transition metal oxide into the precious metals will help improve the electrocatalytic activity. Tungsten oxide can form the synergistic catalytic effect with the noble metal platinum, and perform quite stable in an acidic environment, the composite catalyst uses tungsten trioxide as the carrier has been extensively studied. Pyrochlore tungsten trioxide has a layered structure of multi-dimensional channel, also has a three-dimensional channel, and this structure is conducive to rapid migration and ion exchange to improve the ionic conductivity; at the same time, it enhances its adsorption property, certain amount of ions embedded in the layered structure to form intercalation compound catalytic material. Synthesis of pyrochlore tungsten trioxide by hydrothermal synthesis method, take pyrochlore tungsten trioxide and carbon as the carrier to prepare Pt / WO3-C composite catalyst which is the proton exchange film of fuel cell catalytic material. ...

Tungsten trioxide is one transition metal oxide among a lot of metal oxide, belonging to the n-type semiconductor with its very widespread application. As a semiconductor gas sensor, tungsten trioxide has been considered one of the most promising new oxide sensitive materials to detect NO  x , SO x , NH 3 , H 2 S, etc.. Since carbon nanotubes have been discovered in 1991, the more innovative electrical, magnetic, optical, thermal and other physical and chemical properties of one-dimensional nano-materials rendered have caused more and more attention, and showing its value and broad application prospects. While, compared to the traditional tungsten oxide material, tungsten trioxide nanowire because of its greater surface area has broad application prospects on the fields of gas sensors, electroluminescence, photoluminescence, conductivity electrode and photocatalysis. In addition, the tungsten oxide nanowires also have a higher surface activity and stronger adsorption capacity, th...

Heterojunction two-dimensional material is the cornerstones of constructing nanoelectronics and optoelectronics "buildings", and to be tie basic elements of modern semiconductor industry, which plays an important role in the high-speed electronic devices and optoelectronic devices. Two-dimensional layered materials, including graphene, transition metal disulfide (tungsten, molybdenum, etc.), because of their unique electrical and optical properties, they can act as a constituent unit of the heterostructure. Lateral heterojunction two materials are connected by a covalent bond is formed, because of its simple method for constructing, it has a greater potential in terms of applying in band-gap engineering. With the advent of nano-science and nano technology, the development of plasmon nanostructure is really rapid, and scientists have prepared hydrogen doped of MoO 3  and WO 3  which are namely hydrogen bronze (hydrogen molybdenum bronze and hydrogen tungsten bronze) by simple...

CO, the product of incomplete combustion of carbon fuels and cracking reactions occur at high temperatures, oxidation reaction ect. has become one of the major sources of air pollution, which greatly threats human life and health and environmental protection. The body of CO maximum allowable limit is 10 -4 , while in Europe the provisions of the environment CO must not exceed 10 -5 . So, the detection and controlling of CO is becoming urgent, tungsten trioxide based gas sensor is considered to be the most promising sensor for detecting NO x , O 2  and NH 3  and other poison gases, due to its simple structure, low cost, high sensitivity and gas sensing.  This paper presents preparation method of   tungsten trioxide nanowire CO gas sensor which shows as follow: 1. Dissolve the weighed analytically pure sodium tungstate dihydrate (Na 2 WO 4 .2H 2 O) in an appropriate amount of deionized water, and taken out ice water bath, magnet...

Tungsten trioxide is a unique n-type semiconductor material, that makes it one of the few oxide semiconductors which are easy-to-realize quantum size effect, and performances the excellent properties in photocatalysis, electrochromic, photochromic, gasochromic and other aspects, thus widely used in fields of chemical sensor, fuel cell, light catalyst and so on. Tungsten trioxide has orthogonal, monoclinic, cubic, hexagonal and other crystal structure. Among them, hexagonal tungsten oxide causes many concern because of its special hexagonal passage; many metal ions can be embedded in this hexagonal channel, thereby forming a hexagonal tungsten bronze which exhibits potential application in anode material and rechargeable lithium-ion battery. The crystal structure of the tungsten trioxide is ReO 3  type, the result of A-site cation Absence of ABO 3  perovskite structure, six oxygen atoms constituting the octahedron, W located therein and the neighbor WO6 octahedron l...

Hydrothermal process is carried in a special closed reaction vessel (reactor), the aqueous solution as medium, by heating the reaction vessel to create a high-temperature, high-pressure reaction environment to make the generally insoluble or poorly soluble material to dissolve and recrystallization, and then by filtering, washing, drying and other separation means to get the ultra-fine, high-purity particles. Hydrothermal method for preparing hexagonal tungsten trioxide, its crystalline form is affected by many factors, such as pH value, hydrothermal temperature and additives and others, the following will specifically analyze the impact of various factors. In the hydrothermal environment to prepare tungsten trioxide , the existence of hydrogen ions (H + ) is one of the important factors which affect crystal form of product, especially when the reaction condition is acidic environment. The influence mechanism of pH on tungsten trioxide crystal form is really complex, it is...