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Nanocrystals Properties of a nanocrystals are largely determined by size and shape Size specifies the surface area and the ratio of surface to bulk atoms while the shape controls the facets and determines the surface structure and the fractions of atoms at corners and edges Shape offers greater versatility to nanocrystals as compared to size or other parameters determining the catalytic properties of the nanocrystals Pd nanocrystals has been synthesized successfully in the past decade in a variety of shapes Nanocrystals are divided on the basis of types of facets that are exposed to the surface They are divided into 5 groups Pd nanocrystals are synthesized in a number of shapes rhombic dodecahedrons cubes octahedrons by reduction of H2PdCl4 with ascorbic acid in an aqueous solution which contains cetyl trimethyl ammonium bromide CTAB potassium iodide and Pd cubic seeds Icosahedrons nanocrystals are usually stable at smaller sizes while dodecahedrons shaped nanocrystals are more stable at medium sizes 3 2 Quantum dots Quantum dots are Fluorescent semiconductor based nanoparticles which represent a huge platform for design and development of nano drug delivery vehicles which
Consist of hundreds to a few thousand atoms Quantum Dots have an extremely small core size only 2 10 nm in diameter which ranks across the dimensions of large proteins In fact only gold and magnetic material based nanocrystals possess such dimensions whereas majority of nanocarriers for example polymeric viral and liposomal often show 10 100 nm in size QDots are compact in nature so they show threefold benefits
