ABSTRACT
Nanostructures on the basis of cages, boxes, and cubes are closely related without a de£nite and clear distinction between them, formed by the same elements or compounds, and sometimes confused with one another in different articles. However, the number of reports on nanocubes is currently considerably higher (more than 1200) than those with the two £rst structures. The cages and boxes are generally hollow, and nanocubes can be hollow or £lled. Serious attention is paid to elemental metal (predominantly noble metals such as Au, Pt, and Pd) nanostructures including bimetallic species; in particular, metal hollow nanostructures were extensively reviewed.1 The main metals, obtained in nanocube form, are Au,2 Au/Cu,3 Pt,4 Pt3Co,5 Pd,6 and Rh (Figure 6.1)7 and can be formed competitively with other nanostructures depending on reaction conditions. Nanocube metallic structures can be in equilibrium with boxes and cages (as well as with other nanostructures); thus, Pd nanocubes were converted into nanoboxes and nanocages (NCs) in a one-pot synthesis without the involvement of exotic templates in a solution containing ethylene glycol, water, and poly(vinylpyrrolidone) with the addition of Na3PdCl4 as a precursor to Pd.8 Another example corresponds to silver nanocubes, which, being dispersed in water, were transformed into Pd-Ag or Pt-Ag nanoboxes (Figure 6.2) by adding either Na2PdCl4 or Na2PtCl4.9 Replacement of Ag with Pd resulted in the formation of a nanobox composed of a Pd-Ag alloy single crystal, but the nanobox formed after the replacement of Ag with Pt was instead composed of distinct Pt nanoparticles.
