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 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.

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.

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: