Tungsten Sulfide as Hydrogen Evolution Material

The core of hydrogen evolution materials is catalysts. The traditional platinum catalysts have strong catalytic performance. They have always been the dominant materials in this field. The shortcoming is that platinum metals are too expensive and can produce toxic by-products. Therefore, it is of great significance to find hydrogen evolution materials with low overpotential, low cost, high earth content and large-scale synthesis.

Recently, one-step hydrothermal method has been used to synthesize tungsten sulfide nanosheets directly on tungsten mesh. This material is a safe, non-toxic, low-cost raw material and good hydrogen evolution performance of products. It is a good material to replace precious metals for hydrogen evolution. The main processes are as follows:

(1)The metal tungsten mesh was washed in acetone and absolute ethanol for 20 minutes to remove the chemical oil stains, then rinsed with deionized water, and then dried naturally.

(2)Dissolve 1-30 mmol thiourea in 15-25 mL deionized water and stir evenly to get solution A.

(3)The threading inserts metal tungsten mesh was placed in the hydrothermal reactor, and solution A was poured into the reactor. The filling degree was controlled at 50-90%, 120-200 ℃ for 6-72 h, and the reaction was cooled naturally after the reaction.

(4)Take out the tungsten mesh, wash it with distilled water and absolute ethanol for several times, and dry it for 1-3 hours at 60-100 ℃, then nano-flake tungsten sulfide can be obtained.

The prepared nano-flake tungsten sulfide was used to produce hydrogen from electrolytic water. The results show that the nano-flake tungsten sulfide has good hydrogen evolution performance and low overpotential. When the hydrogen evolution overpotential is 200 mV, the current density is 2.53 mA/cm²; when the overpotential is 300 mV, the current density can reach 32 mA/cm². Its performance is close to platinum, but the cost is much cheaper, which is conducive to the promotion and application in industrial production.