Molybdenum Disulfide (MoS2) – A Versatile 2D Material

Why in news?

Researchers have demonstrated that a monolayer of molybdenum disulfide (MoS₂) can withstand the harsh radiation of space. A radio‑frequency communication system built on a 4‑inch MoS₂ wafer and launched aboard China’s Fudan No. 1 satellite remained stable for nine months in orbit and is predicted to last more than two centuries. This breakthrough highlights MoS₂’s potential for future space electronics.

Background

MoS₂ is a naturally occurring mineral known as molybdenite. Structurally it consists of layers of molybdenum atoms sandwiched between layers of sulfur atoms in a hexagonal lattice. Because the layers are held together by weak van der Waals forces, they can slide over one another easily, making MoS₂ an excellent dry lubricant. Unlike graphite, MoS₂ does not rely on adsorbed water molecules for lubrication and can withstand high temperatures. In its bulk form MoS₂ is a semiconductor and becomes superconducting when doped or subjected to an electrostatic field.

Properties and uses

• High melting point: MoS₂ has a melting point around 1,185 °C and sublimates at about 450 °C, which allows purification by sublimation.
• Dry lubrication: Its layered structure provides low friction without the need for oil or water. MoS₂ coatings are used on machine parts, automobile engines and firearms to reduce wear.
• Electronics: In monolayer form, MoS₂ exhibits a direct bandgap, making it suitable for transistors, sensors and flexible electronics. Doped MoS₂ can display superconductivity.
• Space applications: The recent satellite experiment shows that MoS₂-based circuits can tolerate radiation and survive for decades, opening possibilities for lightweight, low‑power spacecraft electronics.

Significance

• Advanced materials research: MoS₂ belongs to the family of two‑dimensional materials like graphene. Its mechanical strength and electronic properties make it a promising candidate for next‑generation devices.
• Industrial lubrication: Because MoS₂ does not depend on humidity, it can be used where oil or grease is impractical, such as in high‑temperature or vacuum environments.
• Space technology: Radiation‑tolerant MoS₂ circuits could reduce the weight and power consumption of satellites, enabling longer missions and deeper space exploration.

Source: TH