Porosity refers to the presence of pores or voids within a material. In nanotechnology, the control of porosity is essential for applications that require specific surface characteristics. Porous nanomaterials can have a wide range of pore sizes, from micropores (50 nm). The size, distribution, and connectivity of these pores can significantly influence the material's properties and performance in various applications, such as filtration, adsorption, and drug delivery.