Layered materials are substances composed of distinct, two-dimensional layers stacked upon each other. These layers are held together by weaker forces, like van der Waals forces, allowing for unique properties and applications. Here are some examples of layered materials:
Types of Layered Materials
| Material Type | Examples | Characteristics |
|---|---|---|
| Sulfides | Molybdenum sulfide (MoS2), Tungsten sulfide (WS2) | Exhibit high lubricity and are often used in solid lubricants and catalysts. |
| Metal Dichalcogenides | Tungsten diselenide (WSe2), Niobium diselenide (NbSe2) | Possess unique electronic and optical properties, making them useful in electronic devices. |
| Graphite and Graphene | Graphite, Single-layer graphene, few-layer graphene | Graphite is a naturally layered material, and graphene is a single layer of graphite, known for its exceptional strength and electrical conductivity. |
| Clay Minerals | Aluminosilicates, Kaolinite, Montmorillonite | Used in ceramics, construction, and agriculture; possess water retention properties and ion exchange capacity. |
| Layered Double Hydroxides (LDHs) | Various metal hydroxides | Used in catalysis, drug delivery, and environmental remediation due to their high surface area and intercalating properties. |
| Hybrid Inorganic-Organic Compounds | Organic molecules intercalated in layered host materials | Designed with combined inorganic and organic features which enables tunability for specific applications and functionalities. |
Detailed Explanation of Some Layered Materials
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Sulfides & Metal Dichalcogenides: These materials, often of the form MX2 where M is a transition metal and X is a chalcogen (S, Se, Te), are known for their unique electronic band structures. For instance, Molybdenum Disulfide (MoS2) is a widely studied example with applications ranging from lubricants to transistors.
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Graphite and Graphene: Graphite is a natural layered material composed of stacked layers of graphene. Graphene, a single atomic layer of graphite, possesses remarkable properties, including high electrical and thermal conductivity, as well as mechanical strength.
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Clay Minerals: These materials are composed of layered aluminosilicates with varying compositions and structures. These are used in various applications, including the manufacture of ceramic materials, construction materials, and as additives in agriculture to enhance soil properties.
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Layered Double Hydroxides (LDHs): These materials have a positively charged layered structure with intercalated anions in the inter-layer space. This makes them useful in various applications, such as catalysis, environmental remediation, and drug delivery.
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Hybrid Inorganic–Organic Compounds: By combining inorganic layered structures with organic molecules, these materials can be tailored with specific functionalities that aren't possible with inorganic or organic materials alone.
In summary, layered materials display a wide range of properties because of their unique structures. They can be found in various applications from daily life to high-tech applications, making them essential components of many technologies.
