Photocatalytic oxidation technology has good selectivity, can react at room temperature and pressure under mild conditions, and can degrade organic pollutants into non-toxic and harmless inorganic substances. It is a green technology with important application prospects in the field of energy and environment. In recent years, more and more reports have been reported on photocatalytic oxidation of organic wastewater. Semiconductor materials used are also various, such as titanium dioxide, zinc oxide, Fe₂O₃, CdS, WO₃, etc. The photocatalytic stability of WO₃ is good, but its activity is relatively small.

At present, the highest working temperature of the most mature and widely used niobium tungsten hafnium superalloy in the high temperature field is 1050 ~1150 ℃, which has reached 80%~85% of the melting point of the Ni-based superalloys. In order to meet the service conditions of high temperature strength and room temperature plasticity of spacecraft in the temperature range of 1200 1400 ℃, new super high temperature alloy materials with refractory metal matrix are still being developed in China.

Tungsten alloys are alloys based on tungsten with other metals. They have small size, high density, high melting point, high hardness, high wear resistance, high ultimate tensile strength, good ductility, low vapor pressure, high temperature resistance, good thermal stability, corrosion resistance, good seismic resistance, extremely high radiation absorption capacity and excellent impact resistance. It is widely used in industry, military, scientific research, medical treatment, sports and other fields because of its excellent properties such as strength, crack resistance and non-toxicity.

The addition of lanthanum to pure molybdenum not only improves the strength and toughness of molybdenum, but also increases the recrystallization temperature of molybdenum and improves its high temperature resistance. Therefore, lanthanum-doped molybdenum alloys are used to replace pure molybdenum in the preparation of electric heating materials, wire cutting electrode materials, electric light sources and other industries.