Time-dependent hydrothermal synthesis and self-evolution mechanism of Cu ₂O microcrystals

The successive and circulatory evolution of Cu ₂O microcrystal morphology and the reduction from Cu ₂O to Cu have both been investigated by carefully adjusting the hydrothermal heating time. The evolutions of the Cu ₂O morphology, which were from octahedrons to octahedrons, from plump-hexapods to perfect hexabranches, have been attained for the first time. The results of our work clearly demonstrate the effect of hydrothermal heating time on Cu ₂O microcrystal morphology without surfactant or template, with the same initial solution composition, the same solution concentration and the same temperature. In particular, the mechanism of circulatory evolution of Cu ₂O microcrystal morphology and that of reduction from Cu ₂O to Cu have both been investigated in detail.