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Rhenium disulfide (ReS2) has attracted tremendous interests as a promising electrocatalyst for hydrogen evolution reaction (HER) due to its unique distorted 1T structure. However, the controllable synthesis of ReS2 with desired nanostructures is still a challenge for improving its catalytic performance. Here, ReS2 nanoflowers are constructed on conductive carbon cloth by means of ambient pressure chemical vapor deposition. Characterization results confirm that the nanoflower structure with enormous edges is attributed to its propensity of out‐of‐plane growth. To investigate the structure variation of the nanoflowers, systematic growth experiments are carried out. By tuning the growth temperature, gas flow rate, and precursor mass, the edge‐exposed architecture is achieved. The dependence of catalytic performance on microstructures is further established, revealing that the ReS2 nanoflowers with maximized edge sites exhibit optimal catalytic performance. These findings provide a guideline for optimizing the HER performance of ReS2 and broaden the vision of improving novel HER catalysts. [ABSTRACT FROM AUTHOR]

Brookite TiO2 was synthesized by a hydrothermal method, g-C3N4 was prepared by a pyrolytic method, brookite/g-C3N4 composites were prepared by a calcining method, and brookite/g-C3N4/BiOBr ternary composites were prepared by loading BiOBr on the surface of brookite/g-C3N4. XRD and XPS analysis of the composites confirmed the formation of brookite TiO2/g-C3N4/BiOBr. SEM and TEM results confirmed the as-prepared composites were nanosized. The optimum loading amount of BiOBr was 30%. The photocatalytic results showed that the brookite/g-C3N4/30%BiOBr composites degraded rhodamine B completely under visible light irradiation. The degradation ratio of brookite/g-C3N4/30%BiOBr toward rhodamine B was nearly 100% for 2 h, which was much higher than that of brookite TiO2 and brookite/g-C3N4 catalysts. The reason for the improvement of photocatalytic activity might be because the composites promoted the formation of superoxide radicals and the separation efficiency of photogenerated electron-hole pairs. The photocurrent density of the brookite/g-C3N4/30%BiOBr was about 10 times higher than that of pure brookite. In addition, the brookite/g-C3N4/BiOBr showed a good repeatablity of photocatalysis. Ternary brookite/g-C3N4/BiOBr photocatalytic composites were prepared by several steps. TEM showed brookite spindel, BiOBr nanoplates and amorphous C3N4 interwined together. The composites have a good photocatalytic activity for the degradation of RhB solution as well as a good recyclability. The degradation ratio is still close to 100% after four times of recycle. [ABSTRACT FROM AUTHOR]

Single phase of Bi3+, Gd3+, Sm3+ and Eu3+ co‐doped La2MgTiO6 red phosphors were synthesized by high temperature solid‐state method. The phase composition, morphology and fluorescent properties of the phosphors were analyzed by X‐ray diffraction (XRD), scanning electron microscopy (SEM) and fluorescence spectrometer. The La2‐xMgTiO6:xEu3+ phosphors can be excited by UV (396 nm) and blue (465 nm) light‐emitting diode (LED) chips and show a strong red emitting with dominated wavelength at 615 nm. The optimum doping concentration of Eu3+ ion for La2MgTiO6 is x = 0.5. The luminescent intensities of 5D0 → 7F2 transition of Eu3+ in La1.5‐yMgTiO6:0.5Eu3+, yBi3+/Gd3+/Sm3+ were 1.31 times, 1.32 times and 1.88 times that of La1.5MgTiO6:0.5Eu3+ at y = 0.08, 0.06, 0.06 for Bi3+, Gd3+, or Sm3+ sensitizer, respectively. The chromaticity coordinates of La1.44MgTiO6:0.5Eu3+, 0.06Sm3+, (0.6342, 0.3513) were very close to those of the National Television Standard Committee (NTSC) standard red light coordinates. [ABSTRACT FROM AUTHOR]

In order to solve the problems such as singleness of the absorption mechanism, difficulty of dispersion and inability of broadband absorption, carbon nanotubes were successfully prepared on the surface of acid oxidized carbon fiber by chemical grafting method. The effect of oxidation treatment on the carbon nanotubes modified carbon fiber and their electromagnetic properties were investigated. The results showed that the graft amount and graft efficiency of CNT were improved by oxidation treatment, resulting in the enhancement of the dielectric constant and the electromagnetic wave loss performance. At the condition of the nitric acid concentration of 65% and the reaction time of 8h, the grafted CNTs on the surface of CF reached 15.3% without agglomeration, which showed a good electromagnetic wave absorption property. [ABSTRACT FROM AUTHOR]

[Display omitted] • The construction of monolayer WS2 on h-BN is achieved with an all chemical vapor deposition (CVD) approach by using alkali metal salt. • The NaCl was employed as the promoters to lower the deposition temperature of WS2 on h-BN, highlighting the salt-promoted growth characteristics of WS2. • The growth behavior of WS2 on h-BN is systematically investigated through the temperature-dependent growth experiment. • WS2 domains deposited on h-BN exhibit improved optical and electrical properties. Monolayer tungsten disulfide (WS 2), an emerging two-dimensional (2D) direct-bandgap semiconductor, provides new prospects for next-generation electronic, optoelectronic and valleytronic devices. However, the physical properties of 2D WS 2 , are seriously perturbed by various extrinsic disorders to a large extent. Despite encapsulating exfoliated WS 2 with hexagonal boron nitride (h-BN) flakes can effectively screen the surrounding disorders, its scalability is not applicable to large-area electronics. In this work, the construction of monolayer WS 2 on h-BN is achieved with an all chemical vapor deposition (CVD) approach by using alkali metal salt to promote the growth of WS 2. Detailed characterizations indicate that WS 2 deposited on h-BN exhibits improved optical and electrical properties, as compared to those on SiO 2 /Si substrates. Furthermore, the influence of depositing WS 2 on h-BN and salt-promoted growth behavior of WS 2 is systematically investigated, highlighting the important role of salt in constructing the heterobilayers. This work paves a practical way for synthesis of 2D materials on h-BN to further probe their intrinsic properties and enable a plethora of potential applications. [ABSTRACT FROM AUTHOR]

Single phase of PbBi2Nb2O9nanoplates was successfully synthesized by a hydrothermal method for the first time, using Pb(NO3)2, Bi(NO3)3·5H2O, and Nb2O5as the starting materials and NaOH as the mineralizer. The influences of the reaction conditions on the phases and morphologies of the products were investigated by X-ray diffraction and scanning electron microscopy. Diffuse reflectance spectra showed the band gap of as-synthesized PbBi2Nb2O9was 2.79 eV. Meanwhile, the photocatalytic activity for the decolorization of methylene blue under ultraviolet light irradiation of PbBi2Nb2O9plates was evaluated. [ABSTRACT FROM AUTHOR]

The creation and manipulation of one-dimensional conducting channels, V-shaped nanopits, in otherwise insulating BiFeO3 epilayers are reported. The formation and thickness-dependent evolution of nanopits have a close correlation with the relaxation of shear strain that stems from the crystal symmetry mismatch between BiFeO3 and the substrate. The local conduction at the nanopits exhibits a rectification behavior, and is governed by interface-regulated Poole–Frenkel emission. The accumulation of oxygen vacancies near the nanopits not only modifies the interface barrier height, but also delivers donor states in the vicinity of the conduction band edge, and therefore leads to locally enhanced nanopit conductance. Our findings provide a new insight into the interplay between defects and epitaxial strain, and open up a possible avenue for oxide nanoelectronics. [ABSTRACT FROM AUTHOR]