Facet‐Controlled Synthetic Strategy of Cu₂O‐Based Crystals for Catalysis and Sensing

Abstract

Shape‐dependent catalysis and sensing behaviours are primarily focused on nanocrystals enclosed by low‐index facets, especially the three basic facets ({100}, {111}, and {110}). Several novel strategies have recently exploded by tailoring the original nanocrystals to greatly improve the catalysis and sensing performances. In this Review, we firstly introduce the synthesis of a variety of Cu2O nanocrystals, including the three basic Cu2O nanocrystals (cubes, octahedra and rhombic dodecahedra, enclosed by the {100}, {111}, and {110} facets, respectively), and Cu2O nanocrystals enclosed by high‐index planes. We then discuss in detail the three main facet‐controlled synthetic strategies (deposition, etching and templating) to fabricate Cu2O‐based nanocrystals with heterogeneous, etched, or hollow structures, including a number of important concepts involved in those facet‐controlled routes, such as the selective adsorption of capping agents for protecting special facets, and the impacts of surface energy and active sites on reaction activity trends. Finally, we highlight the facet‐dependent properties of the Cu2O and Cu2O‐based nanocrystals for applications in photocatalysis, gas catalysis, organocatalysis and sensing, as well as the relationship between their structures and properties. We also summarize and comment upon future facet‐related directions.

Hollow TiO2@Co9S8 Core–Branch Arrays as Bifunctional Electrocatalysts for Efficient Oxygen/Hydrogen Production

“…As shown in Figure 4a, the TiO 2 @Co 9 S 8 electrode presents a remarkably low overpotential of 139 mV at 10 mA cm −2 , superior to the Co 9 S 8 (222 mV), Co 2 (OH) 2 ; b) Tafel plots of Co 2 (OH) 2 CO 3 , TiO 2 @Co 2 (OH) 2 CO 3 , Co 9 S 8 , and TiO 2 @Co 9 S 8 electrodes; and c) electrochemical stability of the Co 9 S 8 and TiO 2 @Co 9 S 8 electrodes at different current densities and times.…”

“…[1][2][3] The cathodic hydrogen evolution reaction (HER) and anodic oxygen evolution reaction (OER) depend heavily on the development of cost-effective high-performance electrocatalysts. [4,5] Currently, platinum (Pt)/Pt-based alloy and iridium/ruthenium oxides (IrO 2 /RuO 2 ) are considered as the most promising electrocatalysts for HER and OER, respectively, but their scarcity, high cost, and compromised stability hinder their widespread applications.…”

Facet-dependent Cu2O nanocrystals in manipulating alignment of liquid crystals and photomechanical behaviors

“…For Cu 2 O rhombic dodecahedra, they expose the {110} face, which contains many more surface Cu atoms with dangling bonds compared with the {111} face of Cu 2 O octahedra (Fig. 3(c)) [31,32]. Similar to the Cu 2 O octahedra-doped LC system, vertical alignment is induced by doped Cu 2 O rhombic dodecahedra (Fig.…”

The Effects of Exposed Specific Facets and Sulfation on the Surface Acidity of Cu2O Solids

“…Cu 2 O is widely used in gas sensors, solar energy transformations, lithium‐ion batteries and catalysis because of its small band gap (2.17 eV), simple synthetic method, nontoxicity, scalability, and abundance . So, it is reasonable to realize that the synthesis of Cu 2 O with certain exposed facets has aroused extensive attention in the past years . Some morphologies of Cu 2 O reported include cubic exposed {100} facets, octahedra exposed {111} facets, cuboctahedra exposed both {100} and {111} facets, rhombic dodecahedron exposed {110} facets, etc .…”