Photocatalysts are chemical substances which do not change itself under the irradiation of light and can be used as a catalyst. 

Photocatalytic principle: After the photocatalyst is irradiated by light, the valence band electron on the semiconductor surface absorbs the light and is excited to the conduction band. 

With the rapid development of graphene, people get interested in two-dimensional materials. Among these two-dimensional materials, transition metal dihalide has attracted extensive attraction because the thin layer structure of its atom owns the properties of electricity, optics, plasma, electrochemistry and electrocatalysis. 

Tungsten diselenide nanosheet is a kind of two-dimensional graphene-like material. Its main structure is composed of two layers of selenium atoms connected with a layer of tungsten atoms in the middle. This material is a hot research topic in the scientific community. 

Analysis of latest tungsten market from ChinaTungsten Online

Affected by new round of environmental protection checks, sellers became more confidence and tended to stabilize offer levels. However, usual quiet trading activity and lowered tungsten forecast prices from large enterprises and associations still made trading deadlocked.