Experimental evidences of crystal nucleation and growth of platinum nanoparticles with most characteristic roughness heteromorphologies and nanostructures from homogeneous solution

In our research, Pt nanoparticles by polyol method using AgNO₃ were studied by UV-vis-IR spectroscopy, X-ray diffraction analysis, transmission electron microscopy (TEM) and high-resolution (HR) TEM methods. Their specific surfaces were investigated in the controlled size and morphology in the range of 10 nm without AgNO₃, and in the range of 20 nm with AgNO ₃. Here, AgNO₃ is crucial to appearance of polyhedral Pt nanoparticles but their convex or concave roughness characterizations are confirmed in the range of 20 nm without AgNO₃. The high crystallization degree of the as-prepared Pt nanoparticles was discovered in the HRTEM evidences. In addition, the interesting complexity of surface roughness showed important evidences of bonding and chemical changes. Re-nucleations and re-crystallizations at their connections by surface attachment were discovered. The results show importance of controlling size and morphology, and big challenge for HRTEM method is predicted, which is how to measure many nanoparticles with high resolution with good quality of fine lattice-fringe systems around 10 nm.