Oxygen adsorption materials play an important role in catalysis. However, the conventional catalytic mechanism of CO oxidation over copper oxide-based catalysts is based on lattice-oxygen oxidation processes, which neglects the significance of the oxidizability of the copper component and the adsorbed oxygen. Herein, we propose that poorly-crystallized CuO nanorods are capable of adsorbing abundant oxygen along with increasing the Cu oxidation states to close to 3+, meaning that CO catalytic oxidation occurs directly on the adsorbed oxygen and that Cu oxidation states do not fall to 1+ during catalytic reactions. The rate-controlled step is the surface oxidizability of the CuO nanorods, which increases with increasing temperature and oxidizability of the environment involved. These catalytic processes are distinctly different from the conventional case. The unique oxygen adsorption and catalytic properties of the CuO nanorods originate from the increasing trend in Cu oxidation state in the p-type CuO, enhanced by the defect structures and coarse surfaces of the sample. Such structure and morphology characteristics are closely related to the liquid membrane growing environment, which induces poor crystallization of the nanorods. The characterization methods include scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and Fourier transformation infrared spectroscopy (FTIR).

ZnO nanowires with both good crystallinity and oxygen vacancies defects were synthesized by thermal oxidation of Zn substrate pretreated in concentrated sulfuric acid under the air atmosphere, Ar- and air-mixed gas stream. The photoluminescence spectra reveal that only near-band-edge (NBE) emission peak was observed for the sample grown in the air atmosphere; the broad blue–green and the red-shifted NBE emission peaks were observed for the sample grown in the mixed gas stream, indicating that the sample grown in the mixed gas stream has a defective structure and its optical properties can be modulated by controlling its structure. The high-resolution transmission electron microscope and the corresponding structural simulation confirm that the oxygen vacancies exist in the crystal of the nanowires grown in the mixed gas stream. The ZnO nanowires with oxygen vacancies defects exhibit better photocatalytic activity than the nanowires with good crystallinity. The photocatalytic process obeys the rules of first-order kinetic reaction, and the rate constants were calculated.

Single crystalline indium nanowires were prepared on Zn substrate which had been treated in concentrated sulphuric acid by galvanic displacement in the 0.002 mol L−1In2(SO4)3-0.002 mol L−1SeO2-0.02 mol L−1SDS-0.01 mol L−1citric acid aqueous solution. The typical diameter of indium nanowires is 30 nm and most of the nanowires are over 30 μm in length. XRD, HRTEM, SAED and structural simulation clearly demonstrate that indium nanowires are single-crystalline with the tetragonal structure, the growth direction of the nanowires is along [100] facet. The UV-Vis absorption spectra showed that indium nanowires display typical transverse resonance of SPR properties. The surfactant (SDS) and the pretreatment of Zn substrate play an important role in the growth process. The mechanism of indium nanowires growth is the synergic effect of treated Zn substrate (hard template) and SDS (soft template).

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The 3D nanostructured antimony is synthesized by simply immerging an anodically oxidized copper sheet into SbCl 3 -(n-Bu) 4 NBF 4 -DMSO solution at room temperature. The morphology, shape, and structure were characterized by FE-SEM, XRD, and HRTEM. The 3D nanostructured antimony has a regular fourteen-faced polyhedron shape and is constructed by Sb nanowires. The Sb nanowires are single crystals with a rhombohedral crystal structure, the average diameter of the Sb nanowires ranges from 5 to 8 nm. The HRTEM investigation and theoretical calculations indicate that Sb nanowires grow along the arrises of its rhombohedral lattice. The growth mechanism is proposed, the electron transport along Sb nanowires may be anisotropic and results in the preferred orientation of the Sb nanowires growth. The nanocages can be formed by quaric self-assembly of Sb nanowires because of the anisotropy of its rhombohedral crystal structure.