Selective synthesis of gold cuboid and decahedral nanoparticles regulated and controlled by Cu2+ ions

It is found that Cu2+ is an effective agent for the controlled preparation of shaped gold nanoparticles. As the concentration of Cu2+ increases from 0 mM to 0.2 mM to 1.6 mM, the shape of the gold nanoparticles changes from rod to cuboid to decahedron. A possible mechanism based on selectively retarding the 'growth rate of the {111} plane is proposed.