Controlled synthesis of Cu2O cubic and octahedral nano‐ and microcrystals

Abstract Cubic and octahedral Cu 2 O nano‐ and microcrystals were selectively synthesized via a simple wet chemical reduction route at room temperature, with CuCl 2 and NaOH as starting reactants, and ascorbic acid or hydrazine hydrate as the reducer. Hydrazine hydrate could be preferentially adsorbed on different crystal faces of Cu 2 O, affecting the growth rate along the 〈100〉 to that along the 〈111〉 direction, which resulted in the formation of octahedral Cu 2 O crystals. When ascorbic acid was used as the reducer, the growth rate along the 〈100〉 to that along the 〈111〉 direction was different, which resulted in the formation of cubic Cu 2 O crystals. The size of cubic and octahedral Cu 2 O crystals could be varied by adjusting the molar ratio of OH – to Cu 2+ . (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)