One-pot sonochemical fabrication of hierarchical hollow CuO submicrospheres

Hierarchical hollow CuO submicrospheres have been fabricated on a large scale by a facile one-pot sonochemical process in the absence of surfactants and additives. The as-prepared products were investigated by XRD, FESEM, EDX, TEM, SAED, HRTEM and BET nitrogen adsorption–desorption isotherms. The results reveal that hollow pumpkin-shaped structures possess a monoclinic phase CuO with the diameters ranging from 400 to 500 nm, and their walls with around 45 nm in thickness are composed of numerous single crystalline CuO nanoribbons with a width of about 8 nm. The BET specific surface area of the as-synthesized CuO hollow structures was measured to be 59.60 m2/g, and the single point adsorption total pore volume was measured to be 0.1036 cm3/g. A possible growth mechanism for the formation of hierarchical hollow CuO structures was proposed, which is considered to be a sonohydrolysis – oriented aggregation – Ostwald ripening process. The novel hollow CuO spherical structures may utilize applications in biosensors, photonics, electronics, and catalysts.

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► Hierarchical hollow CuO submicrospheres have been fabricated on a large scale.
► A facile one-pot sonochemical method is presented to fabricate hollow CuO spheres.
► The walls of CuO spheres are self-assembled by nanoribbons with a width of 6–8 nm.
► CO2 bubbles generated during the sonochemical process act as soft-templates.