Bottom-up assembly of hierarchical Cu2O nanospheres: controllable synthesis, formation mechanism and enhanced photochemical activities

A facile additive-assisted complex-precursor solution method is demonstrated for one-pot assembly of well-defined hierarchical Cu2O nanospheres with tunable sizes and shapes. Structural and morphological evolutions were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and field-emission scanning electron microscopy (FESEM). The formation mechanism of these hierarchical nanostructures was rationally proposed, which can be attributed to the synergic effect of nanoparticle-aggregation and ripening with facet-selective adsorption. Significantly, it is believed that the additive-driven assembly of hierarchical architectures reported here would provide a facile way to design other exciting metal oxide nanostructures with controllable sizes. The photocatalytic superiority and stability for the methyl orange (MO) photodegradation by the hierarchical Cu2O nanospheres could be attributed to their exposed high active facets, which would be quite feasibly used for application in the fields of photocatalytic hazard pollutants.