Facet-controlled synthesis and morphological evolution of Cu2O microcrystals

Abstract

Cu₂O microcrystals were prepared through reduction of Cu²⁺ ions by glucose in an alkaline aqueous solution. Various shapes of Cu₂O microcrystals were obtained by adjusting the reaction temperature, NaOH concentration, and glucose amount. The morphology of the Cu₂O crystals changed from pure octahedra to beveled cubes via corner-truncated octahedra and truncated cuboctahedra as the reaction temperature was increased. These changes arose because of the growth of the {100} and {110} facets at the expense of the {111} facet with increasing reaction temperature. The morphological evolution of Cu₂O crystals from truncated cuboctahedra to corner-truncated octahedra via corner- and edge-truncated octahedra was observed with increasing NaOH concentration, which occurred because of the growth of {111} facets at the expense of {100} facets during simultaneous growth in the early stage and at the expense of {110} facets in the late stage. The morphological evolution of the Cu₂O crystals from truncated cuboctahedra to pure cubes via beveled cubes and corner-truncated cubes was observed with increasing amount of D-(+)-glucose. The {110} and {111} facets were gradually replaced by {100} facets with increasing amount of D-(+)-glucose.