Size distribution control of copper nanoparticles by optimization of precursor morphology

In the liquid phase synthesis of metallic nanoparticles by electroless deposition, the morphology of product is strongly dependent on numerous synthesis conditions; for example, the type or quantity of solvent, precursor, reductant and dispersant species. In this work, the influence of the surface area of precursor on the size distribution of synthesized nanoparticles was investigated using a kinetic evaluation by quartz crystal microbalance (QCM) measurement. We clarified the correlation between the morphology of product and the deposition behavior such as final deposition amount, termination time and deposition rate derived by QCM measurement. We also measured the immersion potential of the reaction solution, and found that the nucleation and growth of Cu nanoparticles were supposed to proceed with the reduction of Cu(II) ion to Cu as long as the Cu(II) sufficiently exist in the solution. Therefore, the saturation of deposition amount on QCM indicated the consumption of precursors. By this estimation, we demonstrated the size distribution was predictable from QCM measurement, and it was controllable by regulating the morphology of precursor.