Selective etching-assisted construction of novel low-dimensional nanostructures

Successful synthesis of noble metal nanostructures with specific sizes, shapes, and morphologies has made it possible to tailor and tune their properties for various applications. However, with respect to synthesis, it is difficult to produce single-crystal noble metal nanoparticles with well-defined shapes in high yields because they usually have a strong tendency to form twinned structures at small sizes. As a result, the process is typically dominated by twinned seeds (with all possible numbers of twin defects) at early stages and irregular particles with poorly defined shapes in the product. This situation did not change until the Xia group demonstrated a polyol reduction method for the synthesis of single-crystal Ag nanocubes in a hydrophilic solvent, ethylene glycol (EG), with the help of poly(vinyl pyrrolidone) (PVP), a capping agent that binds selectively to the (100) facets (see Fig. 3. 1) [11].