Tungsten alloy shotgun bullet is small. Generally, there are some spherical projectiles. At that time, from the perspective of density and hardness, lead was considered a suitable material for shotgun bullet. However, shotguns are used for hunting animals. If toxic lead bullets are used, it seems that the hunted prey is not so “safe” for eating. While tungsten alloy is non-toxic, environmentally friendly and pollution-free, so it is developed to replace traditional heavy metal lead as the projectile material.

Tungsten alloy armor piercing shell, which consists of a tungsten alloy core encased in a jacket of copper alloy, is a type of ammunition designed to penetrate armor. Such an armor piercing shell is also known as a kinetic energy armor-piercing projectile. It has been reported that the core of the former West Germany’s 105mm armor piercing discarding sabot was made of tungsten alloy containing 95%W-3.4%Ni-1.6%Fe. Its density can reach about 18 g/cm3.

Tungsten alloy bullet is a kinetic projectile that made of environmentally friendly tungsten alloy so that it is well-known as a green bullet. Tungsten alloy bullets are developed by researchers to avoid environmental pollution caused by lead bullets. What is more important is that tungsten alloy bullets have higher accuracy, lethality and penetrability than lead bullets. So, there is no doubt that tungsten alloy will be widely used to replace lead as the bullet material.

Yellow tungsten oxide, namely tungsten trioxide or WO3, is a common semiconductor photocatalytic material. Certainly, there are other common semiconductor photocatalytic materials such as TiO2, ZnO, Fe2O3 and Bi2WO6. Wherein, so far, the most studied material is TiO2. However, due to the shortcomings of TiO2 - wide band gap and low conversion efficiency of visible light, people have begun to improve the light utilization efficiency of photocatalysts from two directions:

As a new energy-saving building material, WO3 electrochromic glass has attracted more and more attention. For example, some experts use a WO3 thin film having nanocrystalline mosaic structure as an electrochromic material, and combine it with NiO to assemble an electrochromic device – an electrochromic glass, with high spectral modulation amplitude.

A yellow tungsten oxide composite film uses amorphous tungsten oxide as a matrix, and the SiO2 nanocrystals are uniformly distributed in the amorphous tungsten oxide. Some experts prepared such a composite film with a spectral modulation amplitude at 633 nm of 46%, a coloring time of 8 s, and a fade time of 4.3 s through the following steps:

As a photocatalyst, yellow tungsten oxide (WO3) has significant volume effects, surface effects, quantum size effects, and macro quantum tunnel effects, so that it has a wide range of applications in environmental pollution purification and energy regeneration, and therefore it has attracted much attention. Compared with commonly used photocatalysts such as TiO2 and ZnO, yellow tungsten oxide has a smaller forbidden band width and a larger light absorption range, thus it can use visible light (accounting for nearly half of the solar radiation energy) more effectively.

Do you know how to prepare rare-earth-doped yellow tungsten oxide photocatalyst? The preparation process of such a photocatalyst: prepare pure yellow tungsten oxide (WO3) powder at first, and then dope WO3 powder with rare earth metal.

By doping modification, yellow tungsten oxide’s photocatalytic degradation can be enhanced. Wherein, metal ion doping is a more common method used. Metal ion doping can improve the surface state of yellow tungsten oxide (WO3) catalysts, inhibit the recombination of photo-generated electrons and holes, and increase surface active groups. Therefore, a detailed study of the effects of metal ion doping on the structure, surface properties and photocatalytic activity of WO3 will help to understand the photocatalytic reaction mechanism and guide the preparation of highly active WO3 photocatalysts.

Yellow tungsten oxide or WO3 can be used as a photocatalyst. Rare-earth-doped yellow tungsten oxide is WO3 doped with rare earth element that has better photocatalytic performance than pure WO3 powder. Rare earth elements are prone to generate multiple electronic configurations. Their oxides have the characteristics of polymorphism, strong adsorption selectivity and good thermal stability. Also, after doping, the light absorption band of the photocatalyst moves to the visible light region.