Europium is silver and white metallic element, it is used as color TV phosphors, and europium has important applications in laser materials and atomic energy industry. Europium content in the crust is 0.000106%, it is the rarest of rare earth elements. There are two isotopes of europium in the monazite in nature: Europium Eu 151 and 153. Europium oxide is also used in recent years of new X-ray medical diagnostic system stimulated emission phosphor. Europium oxide can also be used in the manufacture of colored lenses and optical filters for magnetic bubble storage devices. It is used in atomic reactor for neutron absorbing materials because its atoms can absorb more neutrons than any other element. In addition, it can be used as color TV phosphors, which emits bright red phosphor to make television screen.

The preparation method of europium surface-modified tungsten oxide photoelectrode including following steps:
1) The preparation of amorphous tungsten oxide thin film: adding H₂O₂ in Na₂WO₄ solution to obtain clarification W₂0n₂_ containing electrolyte; and Electrodeposition was carried out to obtain an amorphous tungsten trioxide thin film;
2) The dropwise europium surface modification method: the surface of the thin film orphous tungsten oxide europium nitrate was added solution of Step I), drying to obtain surface-modified tungsten oxide europium thin film;
3) Calcining: the Step 2) surface modification europium obtained tungsten oxide thin film in high-temperature about 450 ° C, cooling and taking out at room temperature to obtain surface-modified tungsten trioxide europium photoelectrode. Its photoelectric performance significantly improved, and the test equipment is simple, it has easy operation, mild conditions, and environmentally friendliness.

Tungsten copper powder injection molding (PIM) is based on conventional powder metallurgy (PM) and combines with plastic molding process to develop a new near net shape molding process. Its appearance makes the conventional metal powder molding process limits on the shape of the product has been a breakthrough, applicable to the preparation of relatively complex geometry, uniform organizational structure, small size, high-performance parts. MIM has many advantages, such as one-step forming, with little or without subsequent processing, minimal dimensional tolerances, high consistency of the batch, injecting material can be used repeatedly, high material utilization, lower cost of production, products surface finish without subsequent processing conditions can still be achieved Ra3.2, nearly fully dense, uniform micro-structure, high flexibility and so on.

Theoretically, injection molding of tungsten copper is used in a proportion of polymer (binder) and tungsten and copper powders under certain conditions, to form a uniform blend having good flowability, molded parts after formation of the desired complex shape by injection then give a final product degreasing, sintering process, and which contains the molding powder, selection and control parameters of the binder are sintered tungsten affect copper powder injection molding process key technologies.

1. Injection Molding Powder: Due to MIM process usually used for preparing parts with small size and complex shape or structure, it has higher requirements compared with conventional powder metallurgy, the finer granularity of powder, which is also the major factor to block it out in developing. Currently the metal powder injection molding process for the production includes water atomization method, aerosol method and carbonyl.

Water atomization can refine the powder, has higher efficiency, be suitable for mass production, which can be widely used in many fields. However, a powder of irregular shape and size, so that it is easy to form an oxide film on the powder surface, thus affecting the performance of the MIM parts; the powder by aerosol method is spherical, the degree of oxidation of the surface of the powder compared to the formation of low-water atomizing method, but also a lower collection efficiency; From the point of view of the characteristics of the powder, the powder purity carbonyl prepared higher, fine-grained, but the process method subject to certain constraints, and now has only used in pure nickel and pure iron.

2. Adhesive: Except sintering process, the adhesive involved in all steps, and any injection molding process defect can not be obtained from the process to remedy or eliminate, so it played a key role in the tungsten-copper powder injection molding. Overall, the main function of the binder is to increase liquidity and to maintain the shape of the powder product, a powder can be well filled with a complicated shape under the effect of the injection pressure of the cavity. From the base of the sub-species, the adhesive can be divided into oil-based, polymer-based, paraffin-based, thermosetting adhesive gel adhesive, etc. PIM ideal binder should have a viscosity and moderate fluctuations, has a certain rigidity and strength, small weight After cooling, the metal powder has good adhesion and capillary force, the contact angle is small, high chemical stability, non-toxic safety, low thermal expansion coefficient, can be used repeatedly, and so on.

3. Degreasing and sintering process: Degreasing process is in fact warming or incubation stage of gradual removal of the adhesive, so the selection of the binder also determines the process for degreasing. The degreasing time should be shortened as far as possible and ensure that the chemical composites of blank within the permitted range. Degreasing methods can be broadly divided into hot degreasing and solvent degreasing, degreasing hot atmosphere can be divided into hot fat, vacuum thermal degreasing, degreasing and oxidation siphon degreasing, solvent degreasing can be divided into the condensed vapor degreasing and supercritical degreasing. The last process is sintering, which rely on heat treatment and promotes the grains flow and improve the bonding strength of the product sintering temperature, atmosphere, heating and cooling speed and other parameters have a certain influence on the accuracy and performance of the final product.

Methylene blue is phenothiazine salt, and it is unstable positive charge. It can be dissolved in water or ethanol, insolubling in ether. Methylene blue is more stable in the air; the solution is alkaline and toxic. Methylene blue is widely used in terms of chemical indicators, dyes, coloring agents and biological drugs. It can be used in the manufacture of ink and color lakes and organisms, bacteria and other aspects of the organization of chromatin. It is used to treat methaemoglobinaemia because of the reduction of methylene blue and its injection. Nitrobenzene is also used for rescue, nitrite and cyanide poisoning. Because of its role of disinfection, methylene blue can be treated with its cystitis and urethritis. In addition, methylene blue will be discharged into the body 30 minutes (injection) several hours (oral) within the urine, which resulting in urine temporarily blue, and it is also used for determination of renal function. In the breeding of ornamental fish, the methylene blue solution is 0.1-0.2ppm that can be used as a disinfection treatment of white spot disease or other diseases.

Tungsten trioxide is a semiconductor photocatalyst that can be used to degrade contaminants in water. In the reaction of photocatalytic treatment of methylene blue with tungsten trioxide, the optimum processing conditions for the tungsten trioxide are dosage 50mg, reaction time 40min, H₂O₂ dosage 4mL. We can determine the degradation reaction in different tungsten trioxide photocatalytic reaction system in the series by a kinetic study. The use of tungsten trioxide photocatalytic degradation of contaminants in water is one of the more popular research topics; the photocatalyst can generate holes and have a strong oxidizing power of hydroxyl radicals in the reaction, which helps it to get so much attention.