Answer:-
Surface area:
- The total surface area (or) the number of the surface atoms increases with the reducing size of the particles.
- The physical and chemical properties property of nanomaterials is size-dependent because on the nanoscale more surface area will be exposed compared to bulk materials.
- If the bulk materials are subdivided into nanomaterials, the collective surface area is greatly increased as shown in the figure.
- Change in surface to area volume on breaking down the molecules affects the physical, chemical, mechanical and other properties invariably.
- At Nano-scale, the material properties change -melting point, fluorescence, electrical conductivity, and chemical reactivity Surface size is larger so a greater amount of the material comes into contact with surrounding materials and increases reactivity
Catalytic properties:
- Nanomaterial-based catalysts are usually heterogeneous catalysts broken up into metal nanoparticles in order to enhance the catalytic process.
- Metal nanoparticles have a high surface area, which can increase catalytic activity.
- The catalytic activity of the catalyst increases with an increase in the surface area hence the nanomaterial exhibits better catalytic activity.
- For example, Gold in the macro medium is an inert catalyst, whereas on the Nanoscale it acts as a good catalyst.