Thermal stability and structural collapse of hollow Pt nanoparticles by molecular dynamics simulations

Hollow Pt nanoparticles exhibit unusual chemical and physical characteristics different from their solid counterparts due to the advantages of low density, high porosity and large specific surface area, possessing important technological applications such as catalysis, optoelectronics, and drug delivery. The thermal stability and deformation are significance for their syntheses and applications. In this article, molecular dynamics simulations using the embedded-atom method have been employed to study the thermodynamic evolution of hollow Pt nanoparticles. Our investigation reveals that when the temperature is 0.1 K, the nanoparticle structure (the shell thickness is 0.5 nm) will deform while others (the shell thickness is 1 nm, 1.5 nm, 2.0 nm, 2.5 nm and 3 nm) remain almost unchanged during the relaxation process. The corresponding temperature of the collapse of the hollow nanoparticles increases with the increase of the shell thickness during the heating process. The temperature range required for the collapse process is very narrow and hollow structure can be transformed into solid structure in a short time. After the particles collapse, the internal atoms are rearranged and still maintain an orderly fcc structure. (authors)