Tungsten oxide (WO3) is believed to be a remarkable and feasible photoactive material due to its stable physico-chemical characteristics under different reaction conditions. Furthermore, WO3 has a band gap energy around 2.6 eV. Nether less, bulk WO3 semiconductor, surface accumulation of photo generated charge carriers led to increase their recombination rate and eventually limiting the photocatalytic efficiency.

Pure tungsten bar is made of 99.95% tungsten power and its forging and annealing process is shown by test. The bar has physical properties e.g. density 19.3g/cm3, melting point (liquid) 3422℃, electricity conductivity 30% IACS min and hardness 69hra min. It owns special characters including low thermal expansion, good thermal conductivity, sufficient resistance and high elastic modulus. The bar is widely applied in various fields, e.g. support line, lead-in line, printer needle, various electrodes, quartz furnace, filament, high-speed tools, automatic products, sputtering target and heating devices with special properties etc. Powder metallurgy is a popular method in production process. 

Employing semiconductor powders as photocatalysis for the degradation of organic pollutants in water has received a lot attention in the last decade. Titanium dioxide (TiO2) inhibits amazing photocatalyst properties including high activity, chemical stability, and low cost. Nevertheless, the photocatalytic activity of TiO2 (with band gap of 3.2 eV and excited by photons with wavelengths under 387 nm) is still limited to irradiation by UV wavelengths, so that photocatalytic process does not occur effectively during the irradiation with solar light as only about 4% of the total radiation of the solar spectrum is in ultraviolet region. 

Currently there are two types of minerals in China: wolframite and scheelite. Tungsten is a kind of rare metal and significant strategic material. It is called "heavy stone" from ancient China. In 1783 tungsten was named by the Spaniard DE Puria. The tungsten content in the crust is 0.001%. Generally the tungsten ores are formed for the activity of granitic magma. Tungsten is a silver-white shiny metal with high melting point and high hardness after smelting. There are more than 20 types of tungsten minerals and minerals containing tungsten which are discovered.