Facile synthesis and shape evolution of highly symmetric 26-facet polyhedral microcrystals of Cu2O

A novel type of high symmetric 26-facet polyhedral microcrystals of Cu2O with well-developed {100}, {110}, {111} crystallographic faces are successfully synthesized in a properly selected reaction medium. These polyhedra exhibit a core-shell structure. An aqueous solution containing CuCl2 center dot 2H(2)O, sodium citrate (C6H5Na3O7 center dot 2H(2)O) complexing agent, glucose reductant, sodium dodecyl sulfate (SDS) surfactant, NaOH, and ethylene glycol (EG) constitutes the functional medium. By altering the EG to the water volume ratio, polyhedral, quasi-cubic, octahedral microcrystals are obtained directly. SDS, EG and C6H5Na3O7 center dot 2H(2)O have been confirmed to be the necessary additives to the development of different crystallographic planes. A possible growth mechanism involving aggregation of seed particles, oriented attachment, ripening process and surface reconstruction is proposed on the grounds of time-dependent experiments. The photocatalytic properties of the polyhedral microcrystals are also investigated.