Search

Highlights • Self-floating Ti3+/N co-doped TiO 2 /diatomite granule catalyst was prepared. • The floating hybrid granule showed better photoactivity compared to powdery one. • The optimal dosage amount was determined. • The synergy between co-dopants, TiO 2 and diatomite were illustrated. • The hybrid granule showed good stability and recyclability. Abstract Powdery photocatalyst has long been investigated and developed, yet its disadvantages such as low light-harvesting and reuse capability in suspension system have greatly hindered its practical application. The proposal of floating photocatalyst provided an alternative method to overcome the above limitations. In this work, TiO 2 nanoparticles were doped by Ti3+ and N, and dispersed onto natural porous mineral diatomite via sol-gel method. The obtained black powder was granulated to produce floating granule catalyst (black Ti3+/N co-doped TiO 2 /diatomite hybrid granule), denoted as b/N-TDHG. The synergy between Ti3+ and N dopants, as well as diatomite and TiO 2 were studied. The photoactivity of b/N-TDHG was investigated via the degradation of antibiotic tetracycline (TC) solution under visible light irradiation, and then the optimal co-doping amount and granule dosage were determined. The optimal granule catalyst presented its removal rate of TC as 92.0% within 150 min, and its rate constant was 0.0144 min−1, while the corresponding powdery sample showed the removal rate of TC as 90.5% during the same period, with its rate constant as 0.0135 min−1. Moreover, floating b/N-TDHG could simply be filtrated from TC solution, and the removal rate slightly dropped to 89.6% after 5 repetitions, presenting good reusability. [ABSTRACT FROM AUTHOR]

Abstract: The water contact angle (WCA) of nanocrystalline TiO2 films was adjusted by fluoroalkylsilane (FAS) modification and photocatalytic lithography. FAS modification made the surface hydrophobic with the WCA up to ∼156°, while ultraviolet (UV) irradiation changed surface to hydrophilic with the WCA down to ∼0°. Both the hydrophobicity and hydrophilicity were enhanced by surface roughness. The wettability can be tailored by varying the concentration of FAS solution and soaking time, as well as the UV light intensity and irradiation time. Additionally, with the help of photomasks, hydrophobic–hydrophilic micropatterns can be fabricated and manifested via area-selective deposition of polystyrene particles. [Copyright &y& Elsevier]

Abstract: Anatase TiO2 hollow microspheres with a high percentage of exposed {001} facets have been successfully synthesized by a one-step hydrothermal strategy in the presence of hydrogen peroxide and hydrofluoric acid solution. It is found that both HF and H2O2 play an essential role in the formation of TiO2 hollow polyhedron TiO2 microspheres with exposed {001} facets. A plausible mechanism for formation of the TiO2 hollow spheres with exposed {001} facets by dissolution–recrystallization and Ostwald ripening is proposed based on the experimental observations. The products exhibited enhanced photocatalytic activities for degradation of methylene blue dye present in aqueous solution under ultraviolet light irradiation at ambient temperature. [Copyright &y& Elsevier]

Abstract: The fabrication of monocrystalline Ni5Sb2 nanowires array into porous anodic alumina membranes by using direct-current potentiostatic electrodeposition technique has been firstly reported. In this paper, the focus is on the effects of Sb content and the co-deposition voltage on the resultant. It was found that Ni5Sb2 nanowires array with a monoclinic structure could be successfully synthesized by regulating these two parameters. The analysis results displayed that the Ni5Sb2 nanowires array was highly filled and ordered, as well as around 80nm in diameter. Structure analysis indicated that the as-deposited nanowires had a highly preferential orientation grown along [022] direction. [Copyright &y& Elsevier]

Highlights: [•] Systematically and comparative microstructure analysis for the SrIrO3 thin films. [•] Meta-stable orthorhombic SrIrO3 phase was obtained under normal conditions. [•] The stabilization of meta-stable orthorhombic SrIrO3 was quantitatively understood by lattice mismatch strain. [ABSTRACT FROM AUTHOR]

Abstract: La-substituted BiFeO3, Bi0.8La0.2FeO3, thin films were fabricated on Pt/Ti/SiO2/Si substrates by pulsed laser deposition. X-ray diffraction and high-resolution transmission electron microscope were used to analyze the structures of the films. The results show the films fabricated under optimized growth condition are (012) textured. X-ray photoemission spectroscopy results indicate that the oxidation state of Fe ion is Fe3+ in the films without detectable Fe2+. The films show low leakage current and excellent dielectric characters. Multiferroic properties with a remnant ferroelectric polarization of 5.2μC/cm2 and a remanent magnetization of 0.02μB/Fe were established. These results have some implications for further research. [Copyright &y& Elsevier]

Abstract: Multicomponents mixture in the procedure of ceramic preparation is an important procedure, but it is difficult as multicomponents are mixed homogeneously in the traditional process. In order to solve this difficult problem, a novel processing (heterogeneous nucleation-and-growth processing) was used to prepare homogeneous distribution powders. Composite coating particles with mullite stoichiometric ratio (consisting of alpha monohydrate bauxite (α-AlO(OH)) cores without aggregation (average particle size 1.23μm) with an outer homogeneous amorphous silica layer) were prepared by heterogeneous nucleation-and-growth processing. Effects of silica content in composite coating particles versus concentration of tetraethylorthosilicate, pH value, reaction time and reaction temperature were studied. A homogeneous amorphous silica layer on α-AlO(OH) cores was confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and zeta-potentials. [Copyright &y& Elsevier]