Exposed Facets-Dependent Catalytic Properties of Nanocrystals: Noble Metals (Pd, Pt, and Au) and Oxides of First Row d-Block Elements.

This review focuses on the recent progress in shape-controlled synthesis and exposed facets-dependent catalytic properties of widely used nanostructured noble metals (Pd, Pt, and Au), bimetallic alloys involving one noble metal, and oxides of first row d-block elements such as titanium oxide (TiO₂), vanadium oxide (V₂O5 ), chromium oxide (Cr₂O₃), manganese oxide (MnO₂), iron oxide (Fe₂O₃), cobalt oxide (Co₃O₄), nickel oxide (NiO), copper oxide (Cu₂O), and zinc oxide (ZnO). The major emphasis is given on the role of shape-controlling agents and experimental parameters to control the exposed facets of the nanocrystals. The importance of different high-index and high-energy exposed facets of noble metals and metal oxides with larger number of unsaturated atoms, edges, vertices, in different catalytic applications is presented. Furthermore, the synergy of both low-energy and high-energy exposed facets for efficient electron-hole separation for enhanced photocatalytic activity is discussed.