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We synthesized Nb x Mo 1-x O 2 series compounds and determined the structure of each component through x-ray diffraction and selected area electron diffraction techniques. For x=0.05, 0.1, 0.2, they possess room temperature MoO 2 monoclinic structure (P 2 1 / c); for x=0.25, 0.3, they become to body-centered tetragonal structure (I 4 1 / a); for x=0.33, 0.6, 0.65, they further turn to TiO 2 rutile-type structure (P 4 2 / mnm). Nb 0.25 Mo 0.75 O 2 has transport and magnetic properties similar to those of NbMoO 4 as paramagnetic metal. Moreover, the UV–vis spectra indicate the metallic property of Nb 0.05 Mo 0.95 O 2 , Nb 0.25 Mo 0.75 O 2 , and Nb 0.6 Mo 0.4 O 2. X-ray absorption spectra at the Mo-L 3 and Nb-L 3 edges present Mo4+/Nb4+ and Mo4+/Nb5+ valence state for Nb 0.25 Mo 0.75 O 2 and Nb 0.05 Mo 0.95 O 2 , respectively. This means the latter can be descripted as Nb 0.05 Mo 0.95 O 2+δ with δ = 0.025. We synthesized a series of compounds Nb x Mo 1-x O 2 and identified the different structures corresponding to various components through XRD analyses and SAED experiments. Furthermore, we conducted physical property studies on the compounds with different compositions. [Display omitted] • Successfully synthesized Nb x Mo 1-x O 2 , including unreported components. • Nb x Mo 1-x O 2 has diverse structures with different chemical contents. • Determining the transport properties of Nb x Mo 1-x O 2. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO 2 ) has been widely investigated as a photocatalyst material because of its stability and hypotoxicity. However, the photocatalytic activity of TiO 2 is suppressed by the large band gap and the high recombination rate of the charge carrier, which leads to confined application. Moreover, how to improve photocatalytic H 2 production without any co-catalyst remains a big challenge. Here, we report a conceptual strategy in a core–shell nanostructure of simultaneously reducing the band gap and the charge carrier recombination rate by introducing a carbon-doped porous TiO 2 layer onto a metallic TiC nanostructure using a facile in situ thermal growth method. TiC@C-TiO 2 core–shell nanostructure materials have higher photocatalytic activity in methanol aqueous solution than those of pure P25 and carbon-doped TiO 2 , which results from enhanced visible light absorption, drastic charge transfer, and the large surface area. Notably, the novel core–shell nanostructures still exhibit excellent photocatalytic H 2 production without Pt co-catalyst. The results demonstrate that TiC is an ideal support for TiO 2 photocatalysts, and this novel core–shell nanostructure can significantly shift the position of the band edge of the obtained material. This study presents a design principle for photocatalytic materials as highly efficient visible light photocatalysts. [ABSTRACT FROM AUTHOR]

Abstract: The 6H and 6M Ba1− x SrxRuO3 at x⩽0.6 with the normal and distorted hexagonal BaTiO3 structures were synthesized by using high-pressure and high-temperature method. It is found that the unit cell volume deviates from Vegard''s law between 0.3 and 0.4 for the solid solutions due to the increasing distortion degree of crystal structure. With the increasing x, the electrical resistivity at the same temperature is increasing. With the substitution of Sr for Ba ion, the 6H BaRuO3 transforms to a Fermi-liquid metal at x=0.25 from the primal non-Fermi-liquid metal, and then becomes a semiconductor at low temperature when x is larger than 0.4. [Copyright &y& Elsevier]

An AA' 3 B 4 O 12 -type perovskite oxide CaMn 3 (Fe 3 Mn)O 12 was synthesized at 8 GPa and 1473 K. X-ray diffraction shows a cubic crystal structure with space group Im -3. The charge states are verified by soft x-ray absorption spectroscopy to be CaMn3+ 3 (Fe3+ 3 Mn4+)O 12 , where the Ca2+ and Mn3+ are 1:3 ordered respectively at A and A′ sites, while the Mn4+ and Fe3+ are disorderly distributed at B site. The spin interaction of A′-site Mn3+ ions causes a long-range antiferromagnetic phase transition at about 39 K. Subsequently, a spin glass transition is found to occur around 14 K due to the randomly distributed Fe3+ and Mn4+ at B site. Moreover, the spin glass behavior follows a dynamic scaling power law. The temperature dependent resistivity can be well fitted by a 3D Mott variable-range hopping model, indicating the insulating nature of CaMn 3 (Fe 3 Mn)O 12 due to the strong electron correlation effects. A new AA' 3 B 4 O 12 -type oxide CaMn 3 (Fe 3 Mn)O 12 was synthesized at high pressure and high temperature. It crystallizes into an A-site ordered quadruple perovskite structure with space group Im -3. A long-range antiferromagnetic ordering and sequentially a spin glass transition are found to occur with decreasing temperature in this compound. The electrical resistivity measurements show a 3D Mott variable-range hopping behavior. Image 1 • A new compound of CaMn 3 (Fe 3 Mn)O 12 was prepared at high pressure and temperature. • It has an A-site ordered quadruple perovskite structure with space group Im -3. • A long-range antiferromagnetic transition is observed at 39 K due to the spin ordering of A′-site Mn3+ ions. • A spin glass transition is found to occur around 14 K due to the randomly distributed Fe3+ and Mn4+ at B site. • It shows a 3D Mott variable-range hopping behavior. [ABSTRACT FROM AUTHOR]