Nanoflakes

Nanoflakes are ultrathin, plate-like nanostructures characterized by two-dimensional morphologies with lateral dimensions ranging from tens to hundreds of nanometers and thickness on the order of a few nanometers or less. As a subset of 2D nanomaterials, nanoflakes exhibit a high surface area to volume ratio and a geometry that emphasizes edge effects and quantum confinement in sufficiently thin samples.

They are composed of a variety of materials, including graphene and other carbon-based systems; metal oxides such as titanium dioxide and manganese oxide; transition metal dichalcogenides like MoS2; and boron nitride. The properties of nanoflakes depend on composition, thickness, lateral size, defect concentration, and surface functionalization, yielding tunable electronic, optical, and catalytic behaviors.

Nanoflakes can be produced by top-down approaches, such as mechanical exfoliation from bulk crystals or electrochemical and liquid-phase exfoliation, often assisted by ultrasonication. Bottom-up methods include hydrothermal or solvothermal synthesis and chemical vapor deposition designed to promote two-dimensional sheet-like growth and fragmentation into flakes. Surface chemistry can be used to stabilize dispersed flakes or to tailor interfaces.

Potential applications span energy storage and conversion, where nanoflakes serve as electrode materials for batteries and supercapacitors; catalysis and sensing, where exposed edges enhance activity; optoelectronics and photonics, where thickness-dependent band gaps enable tailored responses; and protective coatings or EMI shielding. The small size and high surface area enable these properties at low loading.

Challenges include achieving uniform thickness and lateral size distribution, scalable production, and long-term stability in various environments. Ongoing research focuses on controlled synthesis, functionalization, and integration into devices, with attention to environmental and safety considerations in nanomaterial handling.