Tungsten Oxide

Four hydrogen sulfide is a chemical intermediate of nitro spray paint, rubber and other solvents, so is often used in the protection of hydroxyl groups. The catalysts, Lewis acid and ion exchange resin used in the preparation of the four - hydrogen catalyst, all of which have good catalytic effect. However, there are some shortcomings in these methods, such as longer reaction time, reflux, solvent, complex catalyst preparation procedure and unsatisfactory yield. Phosphotungstates have copper phosphotungstic acid , zinc phosphotungstate and aluminum phosphotungstate. As a kind of heteropoly acid salts, phosphotungstates are widely used as catalysts. It has been proved by experiments that the catalytic activity of phosphotungstic acid for the catalytic hydrogenation of four hydrogen peroxide is better than that of the four hydrogenation of alcohol, thus, a green environmental reaction route is provided for the four hydrogen alkylation reaction better than other methods. The results show ...

Chlorothalonil is an efficient fungicide absorbed in organic pesticide, organic compounds but it is also easy to cause pollution of soil. In the process of agricultural operations, the land often contains chlorothalonil which is difficult to degrade, not only the soil ecological structure is affected, but it is often washed by rainwater to enter the river or infiltrate the ground water, causing serious pollution. In recent years, with the tungsten based photocatalyst for environmental, economic, effective and has become a new method for the treatment of organic wastewater, some scholars have found that most of the organic pesticides is easily degraded and mineralized into H 2 O and CO 2  and other small molecules, so the photocatalytic degradation of chlorothalonil is feasible. . Tungsten photocatalysts mainly consist of tungstate and tungsten heteropoly acids, the commonly used method is to use a combination of loading and photocatalyst to form a new composite preparation for ph...

Bismuth tungstate (Bi 2 WO 6 ) is the most common Aurivillius type oxide and is a hot spot in the field of photocatalysis. Most of the traditional photocatalytic reactions are carried out in the suspensions of bismuth tungstate catalyst powders. Although they have high photocatalytic activity, bismuth tungstate powders are easy to agglomerate and difficult to separate and recover. In practice, it was recognized that some measures had enabled bismuth tungstate to work, and some scholars had thought of loading bismuth tungstate onto the cloth. Of course, loading bismuth tungstate on cloth is not a simple mix, and it also requires a series of chemical procedures that combine bismuth tungstate with cloth to function. Acrylic, polyester fiber and so on, have the same effect at last, and their main difference is synthetic method. Some scholars used polyester as the carrier of bismuth tungstate and prepared them by hydrothermal method, the polyester fabric was treated with acetone and eth...

Bismuth tungstate is a popular new visible light catalyst, especially petal shaped bismuth tungstate. It has good light absorption and high stability, and has broad application prospects in the field of photocatalysis. The scholars in our country believe that the proper doping of bismuth tungstate, the preparation of semiconductor compound and assistant modification are effective ways to improve the photocatalytic property of bismuth tungstate. In recent years, graphene has brought tremendous changes to the material industry because of its unique two-dimensional structure, large specific surface area and high electron transmission rate. It has been recognized as the "king of new materials", Chinese scholars believe that graphene as an efficient electronic additive, and Bi 2 WO 6  composite catalyst, will greatly improve its light capture electronic capabilities, thereby enhancing catalytic capacity. However, scholars believe that only graphene is not enough, and the number o...

Ammonium metatungstate (AMT) is one of the most important raw materials and precursors for the preparation of WC. The structure and properties of WC are affected by the physical and chemical properties of precursor. The particle size and structure of precursor will greatly influence the process of reduction and carbonization in the late stage, and then affect the catalytic activity of WC catalyst. In order to obtain precursor with good particle size and good structure, spray drying is usually used. Spray drying has many advantages, such as simple process, no pollution, homogeneous composition, and suitable for mass production. The basic principle of spray drying method is ammonium metatungstate solution by spray drying, in a few seconds, water quickly evaporated into powder, physical and chemical properties of homogeneous granular, hollow spherical or spherical solid products. Many scholars have found that in the spray drying process, the concentration of ammonium tungstate solution h...

  Rubidium, as a rare and weak alkali metal element, has been widely used in organic catalysts, photomultiplier tubes, special glass and anticancer drugs. Rubidium does not have independent minerals, often and other alkali metals coexist in lithium mica, cesium garnet, lithium cesium garnet, natural carnallite, salt lake brine and underground brine. Because of the coexistence of rubidium and sodium and cesium, which are closely related to the physical and chemical properties, the extraction technology of rubidium is very difficult, which results in a large amount of brine rubidium resources not being rationally utilized. The common methods for separation of rubidium and cesium are fractional crystallization, precipitation, solvent extraction and ion exchange. In industrial production, precipitation method is used to separate rubidium and cesium, which is mainly used to separate rubidium and cesium from high content solution. Solvent extraction is easy to realize continuous operatio...

Ammonium paratungstate (APT) is the main raw material for the production of tungsten powder, tungsten carbide powder, tungsten wire and tungsten products. As everyone knows, the tungsten particle size, crystal morphology of its APT has a great "inherited" relationship, so, if want to produce nanometer tungsten powder and tungsten carbide powder, we first need to prepare ultrafine ammonium paratungstate (APT). It is an innovative method to prepare superfine ammonium paratungstate (APT) by microwave ultrasonic combined crystallization. Many scholars have shown that compared with traditional heating crystallization, microwave ultrasonic combined crystallization has obvious advantages in speeding up the crystallization rate, refining the particle size and improving the purity of products. So what's the difference between microwave - ultrasonic combined crystallization and traditional evaporation crystallization? Some scholars have used microwave-ultrasonic combined crystalli...