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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]

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 with improved properties for solar-driven chemical reactions is of great significance in developing green chemistry. Here, a series of Au/CeO 2 hybrid nanofibers with different Au loadings have been fabricated by a simple method of electrospinning followed by calcination in air. The particle size and plasmonic absorption of Au nanoparticles (NPs) loaded in the nanofibers were analyzed and found to vary with the dosage of chloroauric acid in the precursor solution. The Au/CeO 2 hybrid nanofibers were used as photocatalysts for selective oxidation of benzyl alcohol to benzaldehyde with O 2 under simulated sunlight and visible light (>420 nm), respectively. The results showed that introducing Au NPs into CeO 2 nanofibers induced a great improvement in photocatalysis. The degree of improvement increased first and then decreased with the increase in Au loading, reaching an optimal level over 0.5 wt.% Au-loaded CeO 2 nanofibers. The photocatalytic reaction presents a very high selectivity of 100% for benzaldehyde, which is important for organic synthesis. The transient photocurrent responses of the Au/CeO 2 catalysts were also tested for corroborative evidence. After detailed discussion of various factors including plasmonic absorption, charge transfer, and surface activity of the photocatalyst, a possible mechanism for the photocatalytic oxidation of benzyl alcohol occurring at the Au–CeO 2 interface was proposed. [ABSTRACT FROM AUTHOR]

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]