Tungsten atomic number of 74, a density of 19.35g / cm3, has good radiation shielding properties, and does not produce secondary electron radiation, is used to make nuclear radiation shielding material ideal. But it is worth noting that tungsten is a refractory metal with high melting point and poor toughness and toughness. It is difficult to form and process and has high cost, so it is difficult to prepare applied parts with more complex shape. Therefore, it is subject to many limitations when applied.

The preparation methods of spherical tungsten powder are various. The domestic production method is mainly focused on the improvement of traditional production technology, so as to get the tungsten carbide powder with regular shape and fine structure. Recently, a kind of improved method of spherical tungsten powder has been put forward by some scholars.

Spherical tungsten carbide powder is an important thermal spraying material. It is playing a more and more important role in electronic information, metallurgy, machinery and other industries. Compared with the ordinary multi angle tungsten carbide powder, the spherical tungsten carbide powder has many differences.

The defect tungsten oxide has a certain reduction ability, and the two reactants are directly synthesized by in-situ method at room temperature to synthesize Pd / WO₃ composite material. This kind of mild, simple and easy synthesis method, obtained Pd nanoparticles smaller particle size, and evenly distributed in the tungsten oxide nanowires surface.

The composite catalyst styrene can catalyze the defective tungsten oxide, in which the mass proportion of Pd element is 3%. Internal standard method can be used to test the percentage of the product, 1,3,5-trimethylbenzene as an internal standard, the correction factor of 0.8451.

Polypyrrole-coated defect tungsten oxide composites were prepared by chemical polymerization, and then the defect tungsten oxide composite, nitrogen-carbon doped tungsten oxide, was obtained by calcination at high temperature. The synthesis of these two parts is as follows:

To study the electrochemical performance of the tungsten oxide electrode material, the charge-discharge curve of the tungsten oxide electrode material at a constant current density of 100 mA was tested at room temperature. The test voltage range was 0.005-3.0 V. In the first cycle of charge and discharge process, the tungsten oxide electrode discharge capacity of 1811mA, charge capacity of 1168 mA, Coulomb efficiency of 64.5%.

The discharge rate performance of the two electrode materials of tungsten oxide composite electrode and tungsten oxide electrode can be obtained by subjecting the material to multiple charge-discharge cycles with different current densities. Tungsten oxide composite electrodes have reversible capacities of 1004, 795, 578, 400 and 243 mA at current densities of 100, 200, 500, 1000 and 2000 mA, respectively.

In the synthesis of tungsten oxide, ammonium tungstate may be added as the tungsten source. The addition of citric acid can effectively control the morphology of tungsten oxide. Hydrothermal synthesis of tungsten oxide by adding tartaric acid and citric acid and other organic acids can affect the tungsten oxide nanomaterials relative growth rate of different crystal planes to effectively control the tungsten oxide crystal growth and morphology.

The elemental valence state and composition of the prepared palladium / tungsten oxide composite can be measured by XPS spectroscopy. The XPS score of the palladium / tungsten oxide composite clearly shows that the resulting composite contains tungsten, oxygen and palladium, demonstrating the successful synthesis of the palladium / tungsten oxide composite.