Among MoS2, WS2, MoSe2, and WSe2, the intrinsic state of WS2 is a bipolar semiconductor with both n-type and p-type electron transport characteristics. Therefore, graphene-like WS2 films have become the current research in the field of two-dimensional atomic layer materials. The following mainly introduces the research status of photoelectric and electrocatalytic performance of WS2 film.

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.

Through the introduction of the preparation methods (Ⅰ) and (Ⅱ) of tungsten trioxide graphene composite materials, we can know clearly that they all have the disadvantages of complex production process, long reaction time, difficult solid-liquid separation, and low yield. 

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.