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Abstract: La0.5Ba0.5MnO3 nanocubes and nanoparticles were synthesized by hydrothermal and co-precipitation methods, respectively. The catalytic performances and thermal stabilities of the samples in the oxidation of CO and CH4 were evaluated. La0.5Ba0.5MnO3 nanocubes showed much higher catalytic activity and thermal stability in CO and CH4 oxidation compared with the nanoparticles. After running at 560°C for 50h under the reaction conditions in CH4 oxidation, the surface area of the nanoparticles decreased significantly, while the nanocubes well maintained their surface area. Jahn–Teller effect had a significant influence on the catalytic performances of La0.5Ba0.5MnO3 nanocubes and nanoparticles. The much higher catalytic activity and thermal stability of La0.5Ba0.5MnO3 nanocubes were mainly predominated by the perfect single crystal structure. [Copyright &y& Elsevier]

Abstract: The novel hollow Mn3O4-in-Co3O4 and hollow Co3O4 microspheres were prepared through a hydrothermal route, following by subsequent impregnation and annealing. The samples were characterized by SEM (EDS), TEM (ED), XRD, and N2 adsorption. The chemiluminescence (CL) and catalytic properties for CO oxidation over these hollow samples were evaluated. The hollow Mn3O4-in-Co3O4 catalyst showed a stronger CL response to CO and a higher catalytic activity for CO oxidation, compared with the hollow Co3O4 sample, which was attributed to the novel structure of crystals-in-ball. [Copyright &y& Elsevier]

Abstract: The flower-like CuO nanostructures were hydrothermally synthesized without using any template. The influences of hydrothermal temperature and time on the growth of nanostructures were investigated. The samples were characterized by means of scanning electron microscope (SEM), X-ray powder diffraction (XRD), transmission electron microscope (TEM), high-resolution transmission electron microscope (HRTEM), selected area electron diffraction (ED), and N2 adsorption isotherm. Interestingly, these architectures are made of three-order structures. The formation mechanism of the flower-like CuO was proposed and explained. Furthermore, the chemiluminescence (CL) and catalysis properties of the flower-like CuO were also investigated. The flower-like nanostructures showed the high-CL intensities and reactive activities for CO oxidation. The flower-like CuO can be used to fabricate a highly sensitive CL detector. This CL mode is a rapid and effective method for the selection of new catalysts from thousands of materials. [Copyright &y& Elsevier]

Abstract: The hollow Co3O4 microspheres (HCMs) were prepared by the carbonaceous templates, which did not need the surface pretreatment. The chemiluminescence (CL) and catalytic properties for CO oxidation over these hollow samples were evaluated. The samples were characterized by scanning electron microscopy (SEM), energy disperse spectra (EDS), transmission electron microscopy (TEM), selected area electron diffraction (ED), X-ray diffraction (XRD), temperature-programmed desorption (TPD) and N2 adsorption. The influences of filter’ band length, flow rate of gas, test temperature, and particle structure on CL intensities were mainly investigated. It was found that compared with the solid Co3O4 particles (SCPs), HCMs had a stronger CL intensity, which was ascribed to its hollow structure; and that CL properties of the catalysts were well correlated with their reaction activities. Moreover, HCMs were used to fabricate a highly sensitive gas detector, which is a rapid and effective method for the selection of catalysts or the detection of environmental deleterious gases. [Copyright &y& Elsevier]