In addition to in-situ synthesis technology, ex-situ synthesis technology is also a preparation method for tungsten trioxide/graphene composite materials. At present, there are many reports, which mainly include the two steps of pre-preparation of the dispersion of tungsten trioxide nanoparticles and the dispersion of graphene/graphene oxide and the mixing and reduction.

When I receive tungsten iridium stream mouth as my product, I think it as an alloy of tungsten and iridium. But after discussion with our manufacturing department, I found what I was thinking is really a mistake. 

Tungsten trioxide is an n-type wide-band gap semiconductor oxide with low price, easy preparation, stable performance, non-toxic and harmless, and has been widely used in the field of photoelectrochemistry.

The Chinese standard used now is YS/T 854-2012 Tungsten Iridium Stream Mouth, which is under the nonferrous metal industry standard and issued by the Ministry of Industry and Information Technology of the People’s Republic of China.