Question

Distinguish between the mechanisms responsible for the appearance of colors in the suspensions of semiconductor and metal nanoparticles.

Answer 1

Change in the band gap with size leading to the appearance of distinct size depended colors In the suspension of semiconductor there are different size nanoparticle and the band gap depend on the size of these particle which is responsible for colors.

Metal nanoparticle also show bright color but the source of this is different from semiconductor. The phenomenon of surface plasmon resonance (i.e. resonant oscillation of conduction electrons by incident light) is responsible for this.

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