Figure 2 A) Schemes of surface diffusion (middle) or inward
diffusion (right) of the metal phase after surface nucleation. B)
Scanning transmission electron microscopy (STEM) image of the CdSe-Au
heterostructure after 1 h of
reaction. C) TEM image of CdSe-Au heterostructure after 4 h of reaction.
The scale bar is 20 nm. A) Reproduced with
permission.[5e] Copyright 2010, Wiley-VCH. B-C)
Reproduced with permission.[7] Copyright 2013,
Tsinghua University Press and Springer-Verlag Berlin Heidelberg.
2.3. Solution-liquid-solid method
SLS method is a facile synthetic approach for hybrid nanorods using the
pre-synthesized metal nanoparticles. In this process, metal
nanoparticles with low melting points introduced in the organic solvent
are transformed into liquid metal clusters as a catalyst on which
nanocrystals are precipitated, and the growth of
crystals on metal droplets occurs
only at the interface between them.[1f,8] Being
different from the methods of surface nucleation and materials diffusion
which require careful control of synthesis conditions, the ease and
robustness of this method open new opportunities for the preparation of
high quality 1D hybrid nanostructures with relevance in photocatalytic
applications.[1f, 8d] Shen et al. prepared
Ag-ZnS nanorods by the SLS method (Figure 3B, 3C) by optimizing the
diameter of Ag nanocrystals, the concentration of Zn precursor, reaction
time, reaction temperature and other conditions to effectively control
the diameter and length of Ag-ZnS nanorods hybrid
nanostructures.[9]