Unexpected trend for thermodynamic stability of Au@void@AgAu yolk-shell nanoparticles: A molecular dynamics study

Boron Nitride- and Graphene-Supported Trimetallic Yolk–Shell and Hollow Nanoparticles

“…The large nanoparticles with the largest shell−thickness have the smallest r ext / shell−thickness ratio and consequently have the highest void stability. 56 As shown in Figure 2, after the atom collapse, a core− shell structure is formed in hollow Ni@PdAu nanoparticles, while a quasi−Janus structure is formed in yolk−shell Ni@PdAu nanoclusters. In Figure 3, it can be seen that the more disordered nanoparticles are formed from yolk−shell and hollow PdAu@Ni nanoparticles after the atom collapse due to the less surface energy and the tendency of Au atoms to penetrate into the nanoparticle surface.…”

“…A similar result was observed in our previous studies. 55,56 By comparison of the total strain in Figure 11, it is observed that the hollow nanoparticles on the BN substrate have the lowest and most negative amount of strain in the core (=−20.63) and in the shell (=−17.80). As mentioned above, the good atomic match of Pd, Ni, and Au atoms on the middle position of the hexagonal structure of the BN substrate leads to a decrease in strain and higher stability of the nanoparticles.…”

“…The small YSNPs with a large ratio of R ext /shell−thickness are unstable at room temperature and therefore through collapse into the void space, create a more stable Au@AgAu core−shell configuration. 56 Our group also studied the thermodynamic stability of pure Ni and Pd, Ni@Pd, and Pd@Ni HNPs via MD simulation. We found an opposite trend in Ni@Pd and Pd@Ni HNPs in comparison to corresponding bulk materials in such a way that Ni@Pd HNPs exhibit higher thermal stability in comparison with Pd@Ni HNPs.…”

“…There are several studies on the structural stability and thermal behavior of YSNPs and HNPs by our group. − For example, in previous work, we studied the effects of core and shell sizes on the thermodynamic stability of Au@void@Ag YSNPs through MD simulations. Our results indicated that YSNPs are unstable at temperatures below 350 K and through collapse into the void space create a more stable core–shell configuration.…”

“…Results showed that the stability of YSNPs at room temperature is dependent on their size and ratio of external radius to the shell thickness ( R ext /shell–thickness). The small YSNPs with a large ratio of R ext /shell–thickness are unstable at room temperature and therefore through collapse into the void space, create a more stable Au@AgAu core–shell configuration . Our group also studied the thermodynamic stability of pure Ni and Pd, Ni@Pd, and Pd@Ni HNPs via MD simulation.…”