Recently, graphene oxide (GO) has been taken as a host
for ultra-fast
self-assembly of metal nanoparticles [Nat. Commun.
2016,
7, 12332] or synthesis of ultrathin
and mechanically robust lithium foils [Nat. Energy
2021,
6, 790–798]. However,
the main factors dominating preparations of these nanoconfined metals
are still not clear. In this study, the crystal growth mechanism of
copper (Cu) nanosheet-intercalated GO interlayers has been revealed
by combining theoretical models with molecular dynamics simulations.
Both the interlayer spacing and oxidation degree of GO play key roles
in crystal growth velocities, which increase with increasing interlayer
spacings but decrease with increasing oxidation degrees. The phenomenon
is found to be a consequence of crystal growth being energetically
favorable and a small ratio of interfacial van der Waals-affected
zones for larger crystal thicknesses and strong hydrophilic properties
of GO with higher oxidation degrees. In addition, more smooth surfaces
have been observed for nanoconfined metals. These insights provide
an effective method for generating nanocrystalline metals in a nanoconfined
environment.