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A transparent TiO 2 -C@TiO 2 -C free-standing film has been synthesized by two-step hydrothermal method and subsequent thermal annealing. The chemical composition and morphological features of the TiO 2 -C@TiO 2 -C film are characterized using X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and N 2 adsorption-desorption measurement. The results indicate that the flower-like micro/nanostructure TiO 2 -C particle layers are intimately inhered to porous TiO 2 -C fibers. The fibers in film are interconnected each other to form a three-dimensional reticulate microstructure, and exhibit intense visible light absorption and high adsorptivity of dye molecules. The interaction between TiO 2 and its surface carbon layer in TiO 2 -C particle promotes the generation of Ti- O -C bonds, which leads to effective charge transfer. Under visible-light irradiation, TiO 2 -C@TiO 2 -C film presents enhanced photocatalytic activity for degradation of methylene blue. This work may provide a new viewpoint for designing transparent photocatalytic film for promising applications in heterogeneous photocatalysis. [ABSTRACT FROM AUTHOR]

Abstract: TiO2/carbon paper composite materials with a hierarchically porous structure were synthesized by employing a filter paper as the support material and carbon source. The resorcinol–formaldehyde–block copolymer nanocomposite formed by the self-assembly of phenolic resin and F127 under acidic condition was selected as modifier of the microstructure of carbon paper. Results show that the as-adjusted carbon paper preserved the nanostructure of a pure carbonized filter paper. An ordered mesostructure was also formed. This micromorphology resulted in the increased specific surface area, as well as micropore and mesopore volumes, compared with the pure carbonized filter paper. When mesoporous TiO2 was deposited on the carbon paper with ordered mesopore by the evaporation-induced self-assembly route, the TiO2/carbon paper composite materials displayed excellent adsorption property and enhanced photocatalytic activity of methylene blue. [Copyright &y& Elsevier]

Abstract: We prepared hydroxyapatite/alumina (HA/Al2O3) porous composite materials by the in situ growth of HA on lamellar Al2O3 ceramics. The procedure comprises two steps. First, lamellar Al2O3 ceramics with aligned pore channels were obtained by freeze casting Al2O3 slurry. Second, as-prepared monoliths were used as scaffolds and subjected to hydrothermal treatment in the HA precursor solution. We characterized the microstructure, chemical composition, and mechanical properties of synthesized HA/Al2O3. Experiment results show that the addition of H2O2 into the reaction solution plays an important role in controlling the microstructure of the cultivated HA. The formation of HA has no obvious influence on the lamellar architecture of Al2O3 ceramics. The prepared composite materials exhibit superior compressive strength. Combination of the high strength of lamellar Al2O3 with the excellent biological properties of HA increases the potential of obtained HA/Al2O3 for load-bearing biological applications. [Copyright &y& Elsevier]

Abstract: The porous ZrO2 ceramics with ultra-high porosity were produced by combining phase change, heat exchange and freeze drying process of ZrO2 slurries during decompression environment. The prepared slurry was first cooled to near the supercooling point, and then the supercooled slurry was placed on decompression system to induce foaming and solidification until the decompress-freezing process of the slurry completed. After drying and sintering of the green part, an as-prepared ceramic with porosity more than 93% was obtained. It was shown that the porous ceramic was typically composed of large spherical cells, interconnected by near circular windows. Although the mechanical properties in obtained ceramics are not enough to resist high stress, porous ceramics with a number of pores in cell walls and struts may be expected to be applied in high thermal insulation process. [Copyright &y& Elsevier]

Abstract: Hierarchically porous silica ceramics with unidirectionally aligned channel morphology have been synthesized by in situ mineralization of soluble starch monolith. The procedure followed two steps. First, soluble starch monoliths with well-defined uniaxial macroporous structure were prepared by unidirectional solidification process of starch hydrosol or starch hydrogel. Second, such an as-prepared artificial monolith, used as template, was soaked into a surfactant-templated sol–gel solution to mineralize the existing channel structure. It was shown that the macropore size, wall thickness, and macropore morphology in obtained soluble starch materials may be tuned in a certain range, through adjusting the concentration of starch slurry. When initial concentration changed from 10 wt.% to 15 wt.%, the macropore size of soluble starch materials decreased, while the wall thickness increased. Through the second step, porous silica ceramics were obtained after drying and calcining of organic–inorganic hybrid silicate compounds from solution. These resulting products preserved template microstructure in great detail and exhibited narrow macropore size distributions. It was observed that when the soaking time increased from 36h to 84h, the average pore size of the silica ceramics was decreased from 4.1μm to 3.6μm. In addition, in nanopore regime, all the silica monoliths obtained presented a coexistence of uniform worm-like nanopore and lamellar phase feature, and large BET and microporous surface area. [Copyright &y& Elsevier]

Two hierarchically porous silica ceramics with unidirectionally aligned channel morphology have been in situ synthesized by using soluble starch monoliths with well-defined uniaxial macroporous structure as template. Both these ceramics faithfully inherit the structure of soluble starch templates and show a large BET surface as well as a microstructure of uniform worm-like nanopores and a lamellar phase. These materials may be suitable for use in various separation and reaction processes. [Copyright &y& Elsevier]

Abstract: Experiments have been performed to show that the mechanical properties of alumina porous ceramics may be improved by introducing glycerol into the raw slurries and then casting them under a constant cooling rate. The effects of glycerol on the freeze casting process and thereby on the microstructure and mechanical properties of porous ceramics obtained are investigated. It is shown that the addition of glycerol will increase both the slurry viscosity and sample sintered density. SEM images for microstructure of the final ceramics reveal that a good connection between ceramic lamellae has been promoted. This connection makes as-prepared porous ceramics obtain high mechanical properties. For the 30vol.% alumina slurry with glycerol, the axial and radial compression strengths reach to, respectively, 255.1MPa and 105.8MPa. [Copyright &y& Elsevier]

A Janus Cu(OH) 2 @Cu 2 O/Cu mesh was constructed, which successfully used for unidirectional liquid transport and in situ dual-functional water purification with high efficiency. • A Janus Cu(OH) 2 @Cu 2 O/Cu mesh with controllable wettability is synthesized. • In situ reduced Cu 2 O NPs deposit on the Cu(OH) 2 to form a core-shell nanoneedle. • A unidirectional water transport behavior is obtained by adjusting irradiation time. • The mesh exhibits in situ dual-functional water purification with high efficiency. A Janus Cu(OH) 2 @Cu 2 O/Cu mesh has been synthesized by UV irradiation and in situ hydrazine vapor reduction of superhydrophobic Cu(OH) 2 /Cu mesh prepared by electrochemical anodization of Cu mesh followed by ODS modification. The Cu 2 O nanoparticles derived from partial reduction of Cu(OH) 2 deposit on the Cu(OH) 2 to form a core-shell heterostructure, which endows the as-prepared mesh with micro/nanoscale hierarchical morphology. The wettability of different sides of the mesh can be easily controlled by tuning irradiation time and subsequent reduction. As a result, a unidirectional water penetration phenomenon can be obtained. In addition, based on the asymmetric wettability as well as the photocatalytic activity of the Cu(OH) 2 @Cu 2 O nanoneedle decorated mesh, the ultrahigh permeation flux and high separation efficiency with excellent in situ photocatalytic ability can also be achieved. This work may provide a rational and convenient strategy to construct Janus mesh with visible light photocatalysis toward in situ dual-functional water purification. [ABSTRACT FROM AUTHOR]

Abstract: Gathering the photocatalysis of semiconductors and the superduper electron transmittability of graphene, graphene-based semiconductor photocatalytic composites are attracting increasing interest of researchers. In this paper, a Cu2O/reduced-graphene-oxide (Cu2O/RGO) nanocomposite was prepared via a facile wet-reduction process, for removal of organic pollutants. The samples were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and UV–vis spectrophotometry. The nanocomposite is composed of Cu2O nanoparticles with sizes of 100–500nm attached to the RGO sheets. For photodegradation of methylene blue (MB) under visible light, the Cu2O/RGO nanocomposites exhibited greatly enhanced photocatalytic efficiency compared to the pure Cu2O nanoparticles. The enhanced photocatalytic performance was mainly ascribed to the increased adsorptivity to organic dye as well as the efficient charge transportation and separation from Cu2O to RGO. [Copyright &y& Elsevier]

Exploiting photocatalysts/catalysts with characteristics of low cost, high reactivity and easy recovery is of great significance for energy efficiency and environmental remediation. Herein, CuO/TiO 2 hybrid nanofibers with different CuO contents were fabricated by a simple and low-cost method of electrospinning followed with calcinations in air. The hybrid nanofibers possess some distinct merits including mesoporous structure, extended light response range, and large TiO 2 /CuO interface. The CuO/TiO 2 hybrid nanofibers showed improved photocatalytic activity for organic dye degradation under both simulated sunlight (UV–vis) and visible light (λ > 420 nm), compared with pure TiO 2 nanofibers. Both processes exhibited humplike activity dependence upon CuO addition, with a peak at 1 wt.%-CuO content under UV–vis light and a peak at 5 wt.%-CuO content under visible light, respectively. The mechanism for the CuO-content dependent photocatalysis was discussed with the photoelectrochemical analysis in evidence. Moreover, the CuO/TiO 2 hybrid nanofibers exhibited very high catalytic efficiency for the reduction of nitrophenols by sodium borohydride, and the apparent reaction rate constants ascended with the increased CuO content. The optimized CuO/TiO 2 nanofibers are expected to act a highly efficient catalyst to replace the noble metals in this field. Therefore, this work demonstrated a convenient case for the exploitation of noble-metal-free catalysts with high efficiency, to meet the increasing demands of industrial applications at reduced costs. [ABSTRACT FROM AUTHOR]

The Au/TiO 2 hybrid nanofibers composed of mesoporous TiO 2 nanofibers and Au nanoparticles were synchronously fabricated by integrating a facile electrospinning technique and subsequent annealing in air. The Au loading content in the hybrid nanofibers was regulated by varying the dosage of chlorauric acid added in the precursor solution. The compositions, microstructures and optical response properties of the Au/TiO 2 hybrid nanofibers were characterized. The UV–vis spectra of the as-prepared hybrid fibers reveal two absorption bands belonging to the band gap absorption of TiO 2 and the surface plasmon resonance (SPR) of Au nanoparticles. For the catalytic reduction of 4-nitrophenol to 4-aminophenol by sodium borohydride, the apparent reaction rate constant is raised but TOF value of the catalyst decreases, as the Au loading amount in the hybrid fibers increases. This is because the Au nanoparticles with smaller sizes have higher total surface areas at the same weight and therefore show higher catalytic activity. This method for producing Au/TiO 2 hybrid nanofibers is versatile and can be extended to the fabrication of other hybrid nanofibers composed of various noble metal nanoparticles and other mesoporous metal oxide nanofibers, designing of highly efficient catalysts for more important chemical reactions. [ABSTRACT FROM AUTHOR]

[Display omitted] • First preparation of dodecahedrons CeO 2 /Co/C for microwave absorption. • An excellent reflection loss of −68.83 dB at 5.92 GHz with ultra-thin thickness. • Effective absorption bandwidth up to 4.16 GHz under a single thickness. CeO 2 /Co/C dodecahedrons composites with excellent microwave absorption performance were synthesized by using a hydrothermal method. ZIF-67/CeO 2 was first prepared by introducing CeO 2 into the precursor of ZIF-67 and then CeO 2 /Co/C composite was obtained after heat treatment. Impedance matching of the samples could be well adjusted by controlling the content of CeO 2. Unique dodecahedral structure for more interfacial reflection and cerium dioxide oxygen vacancies enhance microwave absorption performance. Specifically, the CeO 2 /Co/C exhibited a minimum reflection loss of −68.83 dB is observed at 5.92 GHz, while the thickness was 3.69 mm. The introduction of CeO 2 effectively enhanced the impedance matching of the materials and improved the microwave absorption performance. Therefore, this CeO 2 /Co/C composite is a promising microwave absorber material with high performance. [ABSTRACT FROM AUTHOR]