Tungsten Oxide

The modification of zinc tungstate by doping rare earth elements is an effective way to improve its luminescent properties. The single crystal of zinc tungstate is rose red, the color makes the luminous efficiency decrease and the decoloration effect is obvious. After annealing for a long time, the ZnWo 4  crystal will disappear gradually, but the annealing of the bulk crystal still has difficulties which can not be overcome. The main problem is that the defect is incomplete and the defects are introduced into the annealing process.  In single doped rare earth crystals, only cerium doped Ce 3+  can recede the color of the crystal, both doped cerium Ce 3+  and lithium li 3+  have obvious decoloration effect on zinc tungstate crystal, especially, the former can obtain colorless crystal by proper doping. The removal mechanism of zinc tungstate may be due to the decomposition of CO 2  in Li 2 CO 3  crystals, CO 2  molecules will be partially retained...

Rare earth ions are rich in energy levels, their luminescence wavelengths can change from ultraviolet to infrared. They are often used as luminescent centers in luminescent materials. Metal tungstate is a kind of important inorganic functional materials, including tungsten ore stone structure of zinc tungstate (ZnWO 4 ) is a self luminous material type. WO 4 2-  itself has self excitation fluorescence, emits blue green light under ultraviolet irradiation, and can effectively transfer energy to rare earth ions. Therefore, it is widely concerned that in the chemical industry, the self luminescent tungstate doped rare earth element is the most effective LED light source acquisition scheme to change its fluorescence color. At present, the synthesis methods of rare earth doped ZnWO 4  are sol gel method, combustion method, hydrothermal method and microemulsion method. Hydrothermal synthesis is a commonly used method for the synthesis of green phosphors ZnWO 4 :Tb 3+ . In the proces...

In recent years, tungstate catalysts have attracted more attention for their narrower band gap and larger visible light range. Zinc tungstate (ZnWO 4 ) is a very representative tungstate material. As an efficient photocatalyst, ZnWO 4  has excellent catalytic activity, good stability, low energy consumption and no secondary pollution, it has a wide range of applications in environmental protection, water treatment and many other fields. But inevitably, zinc tungstate, like bismuth tungstate, titanium dioxide and other photocatalysts, is easy to agglomerate and difficult to recover in practical applications, therefore, searching for an effective carrier is an effective way to improve photocatalytic performance and reduce the amount of zinc tungstate. Bamboo charcoal is a three-year-old alpine bamboo as raw material, by nearly 1000 degrees high temperature firing from a charcoal. Bamboo charcoal has porous and porous structure, its molecule is fine and porous, the raw material is ea...

Four chlorophenol is a major component of biological pesticides, wood preservatives, dyes and rust removing agents. Four chlorophenol is also used in Asia, Africa and South America to prevent and control schistosomiasis; In addition, biological treatment of municipal wastewater and industrial waste water also contains chlorophenols. Four chlorophenol wastewater is a kind of three toxic agent, which is carcinogenic, teratogenic and mutagenic. It is easy to cause serious pollution to the environment and is difficult to decompose, therefore, the United States Environmental Protection Agency (EPA) has included it in the list of 129 priority environmental control pollutants. In recent years, the application of semiconductor photocatalysis technology in environmental management has received extensive attention, among them, the tungstate semiconductor photocatalyst, with its non-toxic and high photocatalytic activity, has gradually replaced the early physical and chemical treatment m...