Facile sonochemical synthesis of hierarchical porous CuO nanotablets

Hierarchical semiconductor CuO nanotablets with pores have been fabricated on a large scale by a facile and one-pot sonochemical process using the copper acetate and ammonia aqueous solution as precursor in the absence of surfactants or additives. The as-synthesized products were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), high resolution transmission electron microscope (HRTEM), selected area electron diffraction (SAED), and N2 physisorption. The results reveal that porous tablet-shaped CuO nanostructures composed of nanoribbons possess a monoclinc phase CuO with the average diameters about 200 nm and around 50 nm in thickness. The Brunnauer-Emmett-Teller (BET) specific surface area and the single point adsorption total pore volume were measured to be 26.8 m2/g and 0.083 cm3/g, respectively. The band-gap energies were estimated to be 2.52 eV from a UV-vis absorption spectrum, which showed the quantum size effects of the nanosized semiconductors. A possible mechanism for porous CuO nanotablets was discussed.