Truncated concave octahedral Cu2O nanocrystals with {hkk} high-index facets for enhanced activity and stability in heterogeneous catalytic azide–alkyne cycloaddition

Abstract

We report a facile synthesis of Cu₂O truncated concave octahedral nanocrystals mainly with {511} high-index facets in a system of oil in water emulsion. In azide–alkyne cycloaddition with water as a green solvent, Cu₂O truncated concave octahedra showed greatly enhanced activity with a turnover frequency (TOF) as high as 2413 h⁻¹, which was about two and four times, respectively, that of Cu₂O rhombic dodecahedra with {110} facets and cubes with {100} facets. After 10 rounds of recycling experiments, the Cu₂O truncated concave octahedra still exhibited good catalytic and structural stability.