Alloys are metals made by combining two or more metallic elements, primarily to provide greater strength or corrosion resistance. The tungsten alloy family has many industrial applications due to its strength. Tungsten offers a unique contribution because it imparts exceptional strength, corrosion resistance and other useful properties to base metals. In addition to being an excellent alloying element, tungsten can also serve as the basis for its own alloys, and this article will focus on the basic categories of these tungsten alloys. Below are some details on the 3 most common tungsten alloys widely used in industry. Their properties and applications will also be introduced.

The current applications on WS₂ nanomaterials still face challenges and should be investigated in depth in the following aspects. Firstly, the study mechanism of HER needs to be deepened and clarified in terms of the fundamental properties of WS₂. Advanced characterization methods, such as in situ techniques, can be combined to analyze the structural changes of the material during the catalytic process and reveal the catalytic process of WS₂-based nanomaterials, especially electrocatalysis.

Recently, researchers demonstrated a specific capacitance of 398.5 F.g^-1 for sheet tungsten disulfide anode materials. However, the performance of these materials remains unsatisfactory. Encouragingly, Nagaraju et al. synthesized WS₂ nanoparticles used as supercapacitor electrode materials, which provided a high capacitance value of 1439.5 F.g^-1 at a current density of 5 mA.cm^-2 and maintained excellent cycling stability of 77.4% after 3000 cycles. This result suggests that WS₂ can be considered a promising candidate for supercapacitor electrode materials.

Tungsten disulfide possesses a much larger interlayer spacing of 0.62 nm than that of graphite (0.34 nm). This would be very favorable for the reversible process of Na⁺ intercalation/de-intercalation, making WS₂ a promising anode material for sodium-ion batteries (SIBs). For example, Liu et al. reported WS₂ nanowires (NWs) with an expanded interlayer spacing of 0.83 nm.

As potential high-capacity anode materials for Lithium-ion batteries (LIBs), TMDCs have gained considerable attention, especially WS2 nanomaterials, which exhibit a higher theoretical specific capacity (433 mAh.g-1) than commercial graphite due to the 2D layer structure and the large platelet space. When used as an anode for lithium-ion batteries, WS2 exhibits an increasing lithium storage capacity. For example, Liu et al. prepared an ordered mesoporous WS2 as an anode for LIBs, which showed a high lithium storage capacity of 805 mAh.g-1 at a current of 0.1A.g-1.

Tungsten disulfide (WS2) is a semiconductor with a band gap, which gives WS2 a wide range of light absorption, and therefore, WS2 can be considered a promising photocatalyst for photocatalysis degradation of organic pollutants and hydrogen production from water decomposition. WS2 extends the light absorption region to the long-wave direction, and through morphological tuning, WS2 can achieve near-infrared photocatalytic activity.

WS₂ has attracted much attention due to its unique structural properties and suitable hydrogen binding energy (comparable to platinum group metals). WS₂ nanomaterials have been extensively investigated for energy conversion and storage systems.

To improve the electrical and catalytic properties of WS₂, the synthesis of WS₂ composites from other materials with good electrical conductivity is a promising approach. Composites are materials in which one material is the matrix and another material is used as the reinforcement. The various materials complement each other in terms of properties and create a synergistic effect, resulting in an overall performance superior to the original material.

In WS₂ hybrid structures, atomic doping is one of the effective ways to change the physical and chemical properties of the material, such as band gap and optical properties. For example, Sasaki et al. demonstrated that the exciton absorption peaks at 1.94 and 2.34 eV, respectively, were broadened by Nb doping. This suggests that excitons in WS₂ monolayers are sensitive to Nb doping because of the enhancement of the inhomogeneous broadening rate.