Potassium bromide limits the growth of silver nanoparticles, resulting in smaller nanoparticle sizes and allowing for size control. Bromide is known to bind strongly to the silver surface, forming silver bromide which stops the surface growth of silver particles

. b) The use of peroxide as an etching agent ensures that the least reactive forms of nanoparticles will survive (or grow faster) and grow at the expense of the more reactive forms. The choice of platelets is largely due to the kinetic factors of their rapid growth along planar twinning defects, where platelets transform into more stable 3D shapes, such as cubes, bipyramids, and decahedra.

c) The smallest volume is the yellow solution (A) and the largest is the blue solution (D). When potassium bromide is not added, the largest nanoscale size is achieved, resulting in a transparent blue scattering with maximum absorption at 690-750 nm. When 40 l of potassium bromide is used, the color of Nanoprism is yellow.

d) The most common silver nanoparticles are selected amorphous spherical particles with a maximum plasmon resonance of about 400 nm and a characteristic yellow colour