Shape-controlled synthesis of polyhedral 50-facet Cu2O microcrystals with high-index facets

Abstract

Perfect polyhedral 50-facet Cu 2 O microcrystals enclosed by high ratio exposed high-index {211}, {522} or {311} facets were successfully synthesized by a facile wet-chemical route under mild temperature and normal pressure. The morphological evolution of 50-facet Cu 2 O polyhedra was studied carefully and in detail by adjusting reaction parameters such as reaction temperature, reaction time, the concentration and type of alkali metal hydroxides and copper salts, and the amount of the reduction agent glucose. On the basis of these results, a formation mechanism of these polyhedra was tentatively proposed. As compared with Cu 2 O cubes and octahedra with low-index {100} and {111} facets, respectively, the as-prepared 50-facet Cu 2 O polyhedra showed higher photocatalytic activities towards the decomposition of the organic dye methyl orange due to more catalytic active sites being held in the high-index facets.

Highly Facet‐Dependent Photocatalytic Properties of Cu2O Crystals Established through the Formation of Au‐Decorated Cu2O Heterostructures

“…Cu 2 O cubes were also found to be inactive toward photocatalytic water splitting . Although Cu 2 O octahedra have been consistently determined to be more active than cubes for photocatalyzed reactions, a number of reports still show that Cu 2 O cubes are moderately photocatalytically active . We believe a part of the reason why this inconsistency exists is the fact that the cubic nanocrystals are not perfectly cubic throughout the sample, or that byproducts exposing other facets may be present .…”

“…[15] Although Cu 2 Oo ctahedra have been consistently determined to be more active than cubes for photocatalyzed reactions, an umber of reports still show that Cu 2 Oc ubes are moderately photocatalytically active. [16][17][18] We believe ap art of the reason why this inconsistency exists is the fact that the cubic nanocrystals are not per-fectly cubic throughout the sample, or that byproducts exposing other facets may be present. [19,20] This is ap roblem requiring careful examinationt oe stablish the true facet-dependent photocatalytic properties of Cu 2 Oc rystals.…”

Facile synthesis, shape evolution and magnetic properties of polyhedral 50-facet Fe3O4nanocrystals partially enclosed by {311} high-index planes

“…4 Most work was focused on noble metal nanoparticles. Until now, only Cu 2 O microparticles with high-index {522}, {211}, or {322} facets, [9][10][11][12] anatase TiO 2 crystals surrounded by high-energy {011} facets, 20 and octahedral SnO 2 nanocrystals bound by {221} high-index facets 21 have been achieved by different groups using a solution process. Until now, only Cu 2 O microparticles with high-index {522}, {211}, or {322} facets, [9][10][11][12] anatase TiO 2 crystals surrounded by high-energy {011} facets, 20 and octahedral SnO 2 nanocrystals bound by {221} high-index facets 21 have been achieved by different groups using a solution process.…”

α-Ferrous oxalate dihydrate: a simple coordination polymer featuring photocatalytic and photo-initiated Fenton oxidations

“…One of its important applications is to purify water and air by thoroughly mineralizing organic compounds into less toxic/nontoxic small molecules [2][3][4][5]. Numbers of classic semiconductors such as TiO 2 [6][7][8], ZnO [9][10][11], WO 3 [12][13][14], Cu 2 O [15], Ta 2 O 5 [16] and g-C 3 N 4 [17,18] have been broadly studied and applied in the degradation of organic pollutants. However, these photocatalysts often suffer from drawbacks such as non/poor visible-light response, high-cost, low photo-stability, etc.…”