The application of semiconductor photocatalyst in the degradation of toxic and harmful organic pollutants is of great significance for solving environmental pollution. However, broadband gap and low quantum efficiency are still the "bottlenecks" of photocatalysts.

At present, the main production mode of tungsten carbide powder is to mix tungsten powder with carbon powder for a long time in a high temperature environment with a protective atmosphere to obtain tungsten carbide powder with grain size of 2-5 micron. However, it is difficult to form a complete single grain of tungsten carbide with grain size of more than 10 micron, which has become a bottleneck restricting the production of coarse single crystal tungsten carbide mining cemented carbide tools.

Graphene is the thinnest and strongest material known in nature. Graphene has high light transmittance, only about 2.3% light absorption, extremely high electron mobility (15,000 cm2/v * s) and very low resistivity. It is a new generation of transparent conductive materials.

Suspension bed hydrotreating technology is an advanced technology for preparing liquid fuel oil from heavy unconventional oil (residue, heavy oil/superheavy oil, shale oil, coal tar, sandstone oil, oil sand asphalt, etc.). Suspension bed hydrogenation process requires catalyst with high activity, high dispersibility, high stability and good economy. It is a challenging task to prepare catalyst for suspension bed hydrogenation process.