Size- and facet-dependent photoelectrochemical properties of Cu₂O crystals

Abstract

For size- and facet-dependent photoelectrochemical (PEC) activity comparison, Cu2O cubes with average sizes of 58, 213, and 441 nm, octahedra, rhombic dodecahedra, and cuboctahedra were synthesized. The crystals exhibit clear...

Photocatalytic Oxidative Amine Coupling with 4-Nitrophenylacetylene-Modified Cu2O Polyhedra

“…Cu 2 O cubes, octahedra, and rhombic dodecahedra were synthesized following our reported procedure (see the Supporting Information). , Initially, K 2 CO 3 (14.7 mg, 0.105 mmol), 4-nitrophenylacetylene (15.4 mg, 0.105 mmol), and Cu 2 O crystals (10 mg) were loaded into a 4 mL vial with a stir bar. Absolute ethanol (1 mL) was then added, and the mixture was sonicated for 10 min until Cu 2 O crystals were completely dispersed and K 2 CO 3 was fully dissolved in the solution.…”

Photocatalytic oxidative amine coupling using polyhedral SrTiO3 crystals

“…Semiconductor crystals generally possess facet-dependent electrical conductivity, photocatalytic activity, and optical properties. 1–6 For instance, Cu 2 O rhombic dodecahedra are notably more photocatalytically active than octahedra, yet cubes are inactive. 3 More recently, BaTiO 3 polyhedra have also been shown to exhibit surface-related piezoelectric responses.…”

Low-Temperature Growth of Rock Salt MnS Nanocrystals with Facet-Dependent Behaviors

“…16 The emergence of these phenomena can be understood to come from a surface layer or region with slight lattice constant differences from the crystal bulk that give X-ray diffraction (XRD) peak shifts. 3,17,18 Different faces should also have subtle atomic position deviations to achieve large facet effects. 18 The atomic position deviations are naturally very small in an ionic solid so high-resolution analytical tools such as high-resolution transmission electron microscopy (HR-TEM) are needed to reveal the surface layer's presence.…”

“…Semiconductor crystals such as Cu 2 O, Ag 2 O, Ag 3 PO 4 , SrTiO 3 , and CdO have been shown to generally exhibit facet-dependent electrical conductivity, photocatalytic activity, and optical properties. – Commercial GaAs, GaN, SiC, and SrTiO 3 wafers also exhibit strong surface-specific conductivity responses. – More recently, the piezoelectric properties of BaTiO 3 crystals have also been found to display a facet effect . The emergence of these phenomena can be understood to come from a surface layer or region with slight lattice constant differences from the crystal bulk that give X-ray diffraction (XRD) peak shifts. ,, Different faces should also have subtle atomic position deviations to achieve large facet effects .…”

“…Semiconductor crystals such as Cu 2 O, Ag 2 O, Ag 3 PO 4 , SrTiO 3 , and CdO have been shown to generally exhibit facet-dependent electrical conductivity, photocatalytic activity, and optical properties. – Commercial GaAs, GaN, SiC, and SrTiO 3 wafers also exhibit strong surface-specific conductivity responses. – More recently, the piezoelectric properties of BaTiO 3 crystals have also been found to display a facet effect . The emergence of these phenomena can be understood to come from a surface layer or region with slight lattice constant differences from the crystal bulk that give X-ray diffraction (XRD) peak shifts. ,, Different faces should also have subtle atomic position deviations to achieve large facet effects . The atomic position deviations are naturally very small in an ionic solid so high-resolution analytical tools such as high-resolution transmission electron microscopy (HR-TEM) are needed to reveal the surface layer’s presence. , The surface layer differences should present dissimilar barriers to charge transport across a particular crystal face to generate electrical and photocatalytic facet effects.…”