Search

• TiO 2 was prepared by a hydrothermal method with PPSU. • Separation of photoinduced carriers has been largely promoted. • The level of •O 2 - is greatly boosted. • PPSU-TiO 2 possess higher photocatalytic activity than TiO 2. In this study, TiO 2 with abundant oxygen vacancies (OVs) was prepared through a hydrothermal method in the presence of polyphenylsulphone (PPSU). Introduction of PPSU results in enriched OVs within TiO 2 and boosted the level of ∙O 2 -, dramatically ameliorating photogenerated charges separation efficiency and elevating photocatalytic activity. Compared with the reference TiO 2 , PPSU-TiO 2 exhibits enhance activity in photocatalytic degradation of rhodamine B (RhB) and tetracycline (TC). Analysis reveals that ∙O 2 - serves as the primary active free radicals in RhB degradation by PPSU-TiO 2. Furthermore, PPSU-TiO 2 maintains high activity over seven successive cycles, demonstrating excellent stability. Therefore, adding PPSU into the synthesis system of TiO 2 is proved to be an effective strategy to enhance photocatalytic performance. [Display omitted] [ABSTRACT FROM AUTHOR]

• Ionic conductivity of Ag 8 SiS 6 crystals is 2.1 × 10−5 S/cm. • New superionic Ag 7+ x (P 1− x Si x)S 6 materials were obtained. • Ionic conductivity was increased 106-fold by P+5 → Si+4 substitution. • Ag 7.25 P 0.75 Si 0.25 S 6 crystals has a maximal conductivity 2.9 × 10−2 S/cm. For the first time, bulk single crystals of the Ag 7+ x (P 1− x Si x)S 6 solid solution were obtained via directional crystallization from the melt. The crystal structure of the Ag 7+ x (P 1− x Si x)S 6 solid solution was determined by the Rietveld method. It was demonstrated that Ag 7+ x (P 1− x Si x)S 6 solid solutions crystallize in two crystal systems—cubic and orthorhombic, and different SG: P2 1 3, F-43m and Pna2 1. The grown crystals were studied by SEM and EDS methods. The electrical parameters of Ag 7+ x (P 1− x Si x)S 6 were studied in wide frequency and temperature ranges. Established that Ag 7+ x (P 1− x Si x)S 6 solid solutions exhibit an increase in ionic conductivity compared to the initial compounds. Among the studied solid solutions, the Ag 7.25 P 0.75 Si 0.25 S 6 sample demonstrated the highest conductivity with values reaching σ ion = 2.9 × 10−2 S/cm. The lowest activation energy value (E a(ion) = 0.2 eV) is also observed for the given composition of solid solutions. The mechanism of ion transport is considered within the context of limiting distances and position occupancy. [Display omitted] [ABSTRACT FROM AUTHOR]

• Refractive index is crucial because it is related to the reflection, transmission, and trapping of light. • The influence of refractive index on optoelectronic devices was explored. • This review provides valuable insights into the realm of perovskite optoelectronic research. Metal halide perovskites have drawn significant attention due to their exceptional optical properties, and recent developments in the field have established them as a primary subject for comprehensive research. Perovskites have been widely applied in optoelectronic devices such as light emitting diodes, solar cells, lasers, and photodetectors due to their favorable optical and electrical characteristics encompassing a narrow emission peak, high optical absorption coefficient, high carrier mobility, and a long carrier diffusion length. Meanwhile, their cost-effective fabrication further contributes to their popularity in these applications. An essential aspect of creating outstanding optoelectronic devices lies in understanding the refractive index, which is crucial because it is related to the reflection, transmission, and trapping of light in perovskite films. Herein, we explore the influence of refractive index on optoelectronic devices and examine the methods employed for light management. This review provides valuable insights into the realm of perovskite optoelectronic research. [Display omitted] [ABSTRACT FROM AUTHOR]

Co (II) ions can be considered as a structure-controlling agent for SnO 2 crystals growing under hydrothermal conditions. It leads to enhanced room-temperature ferromagnetism of flower-like nanostructures. • Co-doped SnO 2 powders were synthesized via a hydrothermal process without surfactants. • Synthesized flower-like structures exhibit the enhanced room-temperature ferromagnetism. • No secondary phases are formed in any of synthesized products. • Co (II) ions serve as a structure-controlling agent during growth of the SnO 2 crystals. In this work, Co-doped SnO 2 powders were synthesized via a simple hydrothermal process without using any surfactants. A detailed microstructural analysis showed that incorporation of Cо (II) ions distorts the SnO 2 lattice. The unit cell volume becomes smaller as the nominal Co content increases. Neither segregated secondary phases nor the Co-rich clusters were detected. The particles of Co-doped SnO 2 self-assembled from low-dimensional building blocks and acquired a three-dimensional hierarchical structure. The dependencies of the magnetic characteristics of the synthesized Co-doped SnO 2 on the concentration of Co are nonlinear. The highest saturation magnetization (3.5 emu/g) of the flower-like structures was found in the material with a Co/SnO 2 mass ratio of 0.06. One of the reasons for the enhancement of room-temperature ferromagnetism in the Co-doped SnO 2 is an anisotropic growth of SnO 2 crystals in the presence of Co (II) ions, which serve as a structure-controlling agent for the growing crystals. [ABSTRACT FROM AUTHOR]

• ZIF-8 was composited with cotton fabric (CF) as a potential functional textile. • CF@ZIF-8 showed good photocatalytic degradation of model organic pollutant RB5. • Composite showed well antibacterial properties to Gram-positive and -negative species. Developing new type of environmental purification materials and antibacterial materials is of great significance. Herein, a novel cotton fiber (CF) based composite CF@ZIF-8 was designed by in-situ growth strategy and was applied in the photocatalytic degradation and antibacterial. Reactive Black KN-B (RB5) was used as a model pollutant. The results showed that the photocatalytic degradation of RB5 was well fitted by the first-order kinetic model and the degradation rate of RB5 solution (20 mg/L) was approximately 89% under visible-light irradiation within 180 min. In addtion, the CF@ZIF-8 composites showed well antibacterial activity against Escherichia coli and Staphylococcus aureus with a bacterial reduction rate exceeding 98%. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • SnSe crystal is grown by a novel Horizontal Bridgman method. • As-grown SnSe crystal is about 100 × 50 × 15 mm3 in dimensions. • SnSe crystal has higher electronic/thermoelectric transport properties than SnSe polycrystal. • The largest ZT crystal is 0.92 and maximum ZT polycrystal is 0.5 around 793 K. Abstract In this work, SnSe thermoelectric (TE) single crystals with size of 100 × 50 × 15 mm3 was grown by a Horizontal Bridgman method. The as-grown crystals had standard Pnma space group at room temperature and its measured stoichiometric ratio (Sn:Se) was nearly 1:1. Besides, polycrystalline SnSe was also prepared by a hot-pressing technique for comparison. The largest power factor PF crystal along (100) facet was 5.08 μWcm−1 K−2 and the maximum PF polycrystal perpendicular to pressure direction was only 2.01 μWcm−1 K−2, which means the grain orientation has significant influence on the electrical properties of SnSe. The measured total thermal conductivity of polycrystalline SnSe (k tot-polycrystal) was always lower than that of single-crystal SnSe (k tot-crystal) during the whole temperature range except near the phase-transition temperature, and their smallest values were all reached 0.44 Wm−1 K−1. Finally, single-crystal SnSe shows a peak ZT of 0.92, which is much excellent than that of polycrystalline SnSe (ZT = 0.5) around 793 K. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Lutetium gadolinium oxyorthosilicates (LGSO) produced by Laser Floating Zone (LFZ). • High growth rate in air of LGSO ((Lu x Gd 1-x) 2 SiO5, x = 0.1, 0.3 and 0.5) single crystal. • Transparency and energy transfer band intensity tailored by the Lu/Gd amount. Abstract Lutetium gadolinium oxyorthosilicates (LGSO, (Lu x Gd 1-x) 2 SiO 5 , x = 0.1, 0.3 and 0.5)) were obtained by the Laser Floating Zone (LFZ) in air at 10 mm/h, much faster than those produced by the standard Czochralski method. The LGSO fibres were structural and optically characterized. Scanning electron microscopy (SEM/EDS) allowed observing homogeneous monophasic crystalline fibres that obey the expected phase transition from P2 1 /c to C2/c monoclinic structures, as revealed by X-Ray diffraction and Raman spectroscopy. Finally, transmission studies in the near UV to visible range allowed to quantify the transmission and to appraise the presence of energy transfer bands that favor their use as host materials in photonic applications. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Monometallic zinc iodate crystal grown by slow cooling technique. • Crystal has transparency window 214–900 nm. • SHG efficiency of crystal is 2.75 times greater than KDP crystal. • Zinc iodate belongs to soft nature of the material. • Results show that zinc iodate crystal is suitable for optoelectronic applications. Abstract The monometallic single crystal of zinc iodate [Zn(IO 3) 2 ] was grown by slow cooling technique with the dimension up to 14 × 4 × 3 mm3 in the period of 35–45 days. Single crystal X-ray diffraction (XRD) analysis shows that the zinc iodate (ZI) crystal crystallizes in monoclinic crystal system with space group P 21. The various functional groups of ZI were identified by FTIR analysis. The optical absorption of the grown crystal has been ascertained by UV–vis-NIR absorption studies. Second harmonic generation (SHG) efficiency of ZI is 2.75 times greater than that of KDP sample. The microhardness test of the grown crystal suggests that the crystal possesses relatively high mechanical strength. From the mechanical test certain mechanical parameters were determined. The dielectric behavior of the ZI crystal at different temperatures with varying frequencies shows the normal behavior activity of the grown crystal. The field dependent conductivity study was carried out. [ABSTRACT FROM AUTHOR]

• 8-hydroxyquinolinium phthalate co-crystals synthesized by slow evaporation. • X-ray diffraction, structure refinement, thermal and mechanical studies were reported. • Intermolecular interactions ascertained by Hirshfeld surfaces and fingerprint plots. • Spectroscopic analysis covered: UV–vis, PL, FTIR, NMR, Z-scan for THG generation. • DFT analysis covered: Optimized Geometry, MEP, NBO, NPA, vibrational assignments, Global Reactivity Parameters. A novel non-linear optical single crystal of 8-hydroxyquinolinium phthalate has been as-synthesised by a slow evaporation solution growth technique. Single-crystal X-ray diffraction analysis affirms that it belongs to a monoclinic crystal system. While UV–visible spectroscopy shows its optical transparency with a direct band gap of 2.80 eV, a photoluminescence study confirms a principal yellow emission at 370 nm excitation. Furthermore, the mechanical and thermal properties along with the functional groups' study have also been laid out in this paper. Intermolecular interactions present in the crystal are ascertained from Hirshfeld surface and fingerprint plot studies. The Z-scan technique has reportedly affirmed third harmonics generation in the same. Theoretical calculations using DFT modelling further testify to the experimental observations thereby laying out the framework of the mentioned crystal in terms of its optimized geometry, molecular electrostatic potential, frontier molecular orbital, natural bond orbital and natural population analysis along with vibrational assignments and UV absorption analysis. [Display omitted] [ABSTRACT FROM AUTHOR]

• High-quality Dy3+/Eu3+/Y3+ tri-doped Na 5 Lu 9 F 32 single crystals were fabricated. • The yellow emission intensity increased by 60.53% after doping 0.5mol% Y3+ ions. • The maximum emission cross-section of 573nm was ∼ 6.06×10−21cm2. High-quality Na 5 Lu 9 F 32 single crystals incorporated with Dy3+, Dy3+/Eu3+, and Dy3+/Eu3+/Y3+ ions were successfully synthesized by a reformative Bridgman technique. A significantly enhanced 573nm yellow emission for the Dy3+/Eu3+ incorporated crystal by dopant of inactive central Y3+ ions was demonstrated upon excitation of 453nm. The broken of the Dy3+ clusters by addition of Y3+ dopant was probably the main reason for the enhancement of the yellow emission. The crystal still held the phase of Na 5 Lu 9 F 32 although the doping level reaches to 1.5 mol% Y3+ while the peaks of X-ray diffraction (XRD) were slightly blue-shifted, and Y3+ ions replaced the Lu3+ lattices as consequence of Rietveld structure refinements of the crystals. The maximum excited absorption and emission cross-sections at 573nm were also computed to be ∼8.91×10−21 and ∼6.06×10−21 cm2 separately. Therefore, the Dy3+/Eu3+/Y3+ tri-doped Na 5 Lu 9 F 32 single crystal was considered as a prospective yellow solid-state laser material for related optical devices. [Display omitted] [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • K 7 CaY 2 (B 5 O 10 ) 3 crystals were grown from new flux. • SHG efficiency for K 7 CaY 2 (B 5 O 10 ) 3 crystals is comparable to that of KDP. • K 7 CaY 2 (B 5 O 10 ) 3 crystals have UV cut off edge at 190 nm. Abstract Non-centrosymmetric borates K 7 CaY 2 (B 5 O 10 ) 3 have been synthesized by solid state reaction and the crystals were successfully grown by the top seeded solution growth method using K 2 O-B 2 O 3 -CaF 2 flux. According to the single X-ray diffraction, the structure belongs to the R 32 space group with lattice parameters a = 13.2516(2) Å and c = 14.9679(3) Å. IR, Raman, absorption spectra as well as data on melting temperature were obtained for the crystal. The short edge of UV absorption and SHG intensity comparable with KH 2 PO 4 (KDP) suggests that this crystal is a promising nonlinear-optical material. [ABSTRACT FROM AUTHOR]

Large-sized γ-CuI single crystals with ultrafast scintillation property were grown in LiI acetonitrile solvent through evaporation technique. The LiI exhibits unique properties to γ-CuI single crystal preparation. One is that it increases the solubility of CuI in the solvent, which gives rise to a largest-sized (23 × 14 × 2 mm 3 ) single crystal with the high optical transmission (over 60%) in the wavelength region of 435–800 nm. The other feature is that it acts as an effective isoelectronic dopant and improves the molar ratio of copper to iodine, which greatly enhances the near-band-edge emissions (411 and 432 nm) and suppresses the broadband emission (680 nm). The decay time of the fast emission under pulsed X-ray excitation is shorter than 450 ps. The results will give a guidance for optimizing the properties of γ-CuI single crystal as an ultrafast scintillator. [ABSTRACT FROM AUTHOR]

We report the single crystal growth of cubic antiperovskite Ca 3 PbO by a Ca-self-flux method. Cubic crystals, 1 mm in size, were successfully obtained through the use of iron crucibles sealed in stainless steel capsules. The crucible material and sealing method were found to be critical factors for achieving large crystals with low carrier density. The crystals were subsequently characterized by powder and single-crystal x-ray diffraction experiments, electron-probe microanalysis, and Hall effect measurements. Through the use of short stainless steel rods as tight caps for the crucible and fillers to occupy extra space in the capsule, the Ca evaporation loss of the flux, which contributes to Ca vacancy formation, was effectively reduced. Hence, the hole carrier density in the single crystal was reduced to 4.0 × 10 19  cm −3 . The crystal synthesized under optimized growth conditions showed clear Shubnikov-de Haas oscillations, indicating its high purity and homogeneity. [ABSTRACT FROM AUTHOR]

Single crystals of pure and Er 3+ doped BaLaGa 3 O 7 were grown successfully by the Czochralski technique. The absorption spectra, emission spectra including up-conversion, near-infrared and mid-infrared fluorescence spectra, as well as the fluorescence decay curves were measured at room temperature. The optical parameters of absorption and emission cross sections, the fluorescence lifetimes were evaluated and compared. Based on the Judde-Ofelt theory, Judde-Ofelt parameters such as the fluorescent branching ratios, the spontaneous transition probabilities and the radiative lifetimes were calculated. According to the energy transfer diagram, the rate equation model was built and discussed. In summary, Er 3+ : BaLaGa 3 O 7 crystal is attractive and significant as laser gain material for realization of ∼2.7 μm laser output. [ABSTRACT FROM AUTHOR]

A series of monodisperse cruciate multilayer H 3 Sr 6 (PO 4 ) 5 ·2H 2 O:Eu 2+ microarchitectures assembled by crossed nanorods have been successfully synthesized via a facile surfactant-assisted hydrothermal route. XRD and FT-IR confirmed the existence of crystalline water in the phosphor. The FE-SEM images revealed that the phase and morphology of resulting samples were strongly depended on the optimization of the reaction conditions, especially the pH value and the molar ratio of citric acid (CA)/Cations. Furthermore, the possible growth mechanism of H 3 Sr 6 (PO 4 ) 5 ·2H 2 O:Eu 2+ microarchitectures was proposed in detail. Under near-ultraviolet excitation of 365 nm, the as-obtained H 3 Sr 6 (PO 4 ) 5 ·2H 2 O:0.05Eu 2+ sample exhibited intense wide characteristic blue emission of Eu 2+ , which could be decomposed by Gaussian fitting into two peaks corresponding to different Eu 2+ luminous centers. The present results demonstrated that the morphology-tunable H 3 Sr 6 (PO 4 ) 5 ·2H 2 O:Eu 2+ microarchitecture could be used as a potential candidate for future optoelectronic device applications. [ABSTRACT FROM AUTHOR]

The YVO 4 nanospindles with well-crystallization were synthesized through a facile and rapid chemical conversion route. The synthesis started with the precipitation of sheet-like yttrium precursor Y 2 (OH) 5 NO 3 ∙nH 2 O at room temperature. With the addition of vanadate, YVO 4 nanospindles were formed at the expense of the precursor in less than 10 min at 120 °C. The obtained particle shape and size are insensitive to experimental parameters, such as pH value and reaction temperature. The synthesis route is environment-friendly which involves no template or surfactant, but only relates to facile aqueous conditions at low temperature. We also investigated the luminescence properties of YVO 4 :Eu 3+ and gold functioned Au/YVO 4 :Eu 3+ products. Under UV excitation, both samples show strong red luminescence due to the radiative transitions of Eu 3+ , while the excitation spectra vary significantly. The interactions between Au nanoparticles (NPs) and the YVO 4 :Eu 3+ NPs were also investiged. [ABSTRACT FROM AUTHOR]

Multiwalled carbon nanotubes (MWCNTs) were fabricated via the detonation of a mixed gas consisting of ferrocene vapor, methane, and oxygen. The samples were characterized using transmission electron microscopy, X-ray diffraction, Raman spectroscopy, vibrating sample magnetometry, and a vector network analyzer. The results indicate that the samples were MWCNTs that were about 30 nm in external diameter, about 15 nm in inner diameter. The ferrocene dosage had an obvious effect on the morphology, degree of graphitization, and magnetic property of the MWCNTs. The growth mechanism of the MWCNTs in the gaseous detonation process was discussed using the detonation Zeldovich-von Neumann-Döring model and a vapor-liquid-solid growth model. The minimum reflection loss of the MWCNTs was −6.1 dB at 11.2 GHz with a thickness of 2 mm, which is lower than that of the MWCNTs prepared via other methods, and the reasons for this result are analyzed in the paper. [ABSTRACT FROM AUTHOR]

In the present work, Cu 3 SbSe 4 thin films have been successfully synthesized by chemical bath deposition (CBD) involving a sequential deposition of antimony selenide (Sb 2 Se 3 ) and copper selenide (CuSe) films and then annealing in a vacuum atmosphere. The influence of CuSe deposition time on the previously deposited Sb 2 Se 3 films was investigated to obtain the ternary phase. A study of the structural, morphological, optical and electrical properties of these films was carried out using appropriate characterization techniques. X-ray diffraction analysis revealed that the films show a tetragonal crystalline crystalline structure corresponding to the Permingeatite phase (Cu 3 SbSe 4 ). The crystal size increases with the CuSe deposition time. It is identified by Raman spectroscopy that at low CuSe deposition times a low concentration of Sb 2 Se 3 coexists in the thin film. The optical band gap energy of these films was evaluated in the range of 0.67–1.18 eV, decreasing by increasing CuSe deposition time. By field-emission scanning electron microscopy (FESEM) a morphological study was carried out, observing that by increasing the deposition time of CuSe there is an increase of agglomerates and decrease the porosity in the samples. An elemental analysis was carried out by energy dispersive X-ray spectroscopy to observe the composition and elemental distribution in the ternary compound. The films showed a p-type electrical conductivity with values between 0.417 and 55.55 (Ω cm −1 ). The mobility and carrier density were performed by Hall Effect and Thermoelectric measurements observing a slight increase in the values by increasing the time of CuSe deposition. All results obtained for thin films of Cu 3 SbSe 4 suggest that it could be used as an absorber material in a solar cell or thermoelectric material. [ABSTRACT FROM AUTHOR]

Hierarchical three dimensional MoS 2 nanostructures composed of small sheet-like nanostructures are successfully prepared using a simple two-step hydrothermal process with sodium dodecyl sulfate (SDS), as a surface modifier. The as-preparedMoS 2 nanospheres are characterized by XRD, BET, XPS, EDS, SEM and HRTEM. The gas–sensing properties of as–prepared MoS 2 nanostructures are tested at 175–230 °C temperatures for 50–500 ppm concentration range, using an efficient ceramic-tube sensor system via an intelligent gas testing system. A high response and selectivity towards carbon monoxide than other gases is observed. Comparative studies of MoS 2 nanostructures for different concentration of carbon monoxide gas and definite sensor-stability for different gases are studied, as well. The sensor fabrication and sensing mechanism is discussed as well. [ABSTRACT FROM AUTHOR]

A fast scintillation crystal, γ-CuBr, was successfully grown by hydrothermal method with NH 4 Br mineralizer. The element mole ratio of the Cu/Br crystal was about 0.91 caused by the crystal grown in a rich bromine environment. Under ultraviolet excitation, the crystal exhibited an intense 420 nm emission, a shoulder emission at 428 nm and a weak broadband emission at 560 nm, which could be related to free exciton recombination, Cu and Br vacancies, respectively. Furthermore, the X-ray excited optical luminescence of the crystal was first reported, and a strong 430 nm emission was observed. The analysis of luminescence decay kinetics revealed that the 430 nm emission is composed of two components with an average decay time of 36.9 ns. It means that the γ-CuBr crystal is a promising candidate for applications in fast radiation detection. [ABSTRACT FROM AUTHOR]

Two approaches to using optical floating zone (OFZ) technique for single crystal growth of the perovskite Pr 1−x La x AlO 3 are discussed, along with the influence on the physical properties of the resulting single crystals due to oxidizing and reducing post anneals. In method one (M1) we used pre-reduced Pr 2 O 3 powder starting material, while in the other method, M2, we employed an argon 5% hydrogen reducing environment during the floating zone single crystal growth. Magnetic susceptibility of the low temperature monoclinic phase of Pr 0.2 La 0.8 AlO 3 is shown to be sensitive to the precise annealing protocol followed. For the post-growth reduced single crystal the magnetic susceptibility is flat across the R-3 c to C2/ m structural transition, whereas the oxidized and as-grown samples display a sharp upturn and downturn, respectively. We attribute the low temperature susceptibility differences to relative proportions of Pr 3+ and Pr 4+ . [ABSTRACT FROM AUTHOR]

• Three quaternary chalcogenides, BaCeCuSe 3 , BaCeAgS 3 , and BaCeAgSe 3 , were synthesized and characterized. • The BaCeCuSe 3 exhibited ultralow thermal conductivity (0.43 Wm−1K−1) at 773 K. • The optical absorption bandgap studies showed the semiconducting nature of the three compounds. • The photovoltaic study of BaCeAgS 3 showed the highest efficiency of ∼4% among the three compounds. • Theoretical thermoelectric studies show a zT value of >1 on hole-doping in the BaCeCuSe 3. In this study, we present the syntheses of three chalcogenides, BaCeCuSe 3 , BaCeAgS 3 , and BaCeAgSe 3 , using the sealed-tube method. The single-crystal X-ray diffraction technique is employed to determine the structures of BaCeAg Q 3 (Q = S / Se) for the first time. These isostructural Ag-containing compounds (space group: Cmcm) crystallize in the KCuZrS 3 structure type. Rietveld refinement study of the BaCeCuSe 3 sample confirms its orthorhombic Eu 2 CuS 3 type structure (Pnma). The building blocks of these pseudo-two-dimensional structures are tetrahedral MQ 4 (M = Cu/Ag) and octahedral Ce Q 6 polyhedra, which are conjoined to form ∞ 2 [Ce MQ 3 ]2− layer. The optical absorption studies reveal the semiconducting nature of the BaCe MQ 3 with bandgaps of 1.4(2) eV-1.5(2) eV consistent with their electronic structures calculated using DFT studies. The thermal conductivity (k tot) measurements showed extremely low k tot values (0.43–0.67 Wm−1K−1) for these samples at 773 K. Solar cells were fabricated with the chalcogenides and the highest efficiency of ∼4% was achieved with BaCeAgS 3. [Display omitted] [ABSTRACT FROM AUTHOR]

• The TiO 2 nanomaterials were fabricated using a microwave in situ route. • The effect of microwave treatment time on the exposure of facets in TiO 2 was confirmed. • The TiO 2 nanomaterials were efficient in the elimination of metronidazole under UV-LED. • The possibility of surface heterojunction is a key element to improve photoactivity. This study present a novel microwave strategy to fabricate highly active anatase particles, exposing {101} and {001} facets. Microwave treatment time was shown to determine the growth of crystals in a certain direction. To the best of our knowledge, it is the first report revealing that the contact time of TiO 2 crystals with fluorine ions during the microwave process affects the formed morphology, in particular exposed facets ratio. The important element of this study was a parallel approach to produce active photocatalysts and a convenient UV-LED light source. The simultaneous use of synthesized anatase nanocrystals with exposed {001}/{101} facets and tailor-made LED photoreactor led to the enhanced elimination of metronidazole. Photocatalytic studies showed greater activity in the elimination of metronidazole with increasing microwave exposure time, which was associated with the presence of the surface heterojunction {001}/{101}, leading to better separation of charge carriers. [Display omitted] [ABSTRACT FROM AUTHOR]

• 11B solid-state NMR studies on Sc 2 Ir 6-x Ni x B vs temperature and Ni substitution. • We present an atomic-level view of the lattice via quadrupolar interactions and paramagnetic effects upon Ir replacement. • NMR highlights short-range ordering and structural displacement that is not visible by XRD. • Nanoscale phase separation of ordered and disordered phases was studied by solid-state NMR. Intermetallic borides, such as the Sc 2 Ir 6- x Ni x B (x = 0–6) series, exhibit technologically relevant physicochemical properties, that are all associated to boron ordering. X-ray diffraction has not yet fully investigated the effect of Ir substitution by Ni on the boron arrangement of these borides, primarily due to its weak scattering factor. Herein we employ 11B-NMR to probe the boron ordering of Sc 2 Ir 6- x Ni x B series at atomic scale, overcoming limitations on low- Z materials. Across the Ni-substitution range, the spectral parameters and spin-lattice relaxation rates (T 1 − 1) were responsive to changes in crystal symmetry and valence charges. The spectral analysis and T 1 − 1 vs. x reveal that Ni substitution causes phase separation at the nanoscale between ordered and disordered borides. For x = 3, T 1 − 1 is T -independent, indicating a relaxation mechanism caused by paramagnetic centers whereas x = 5 follows a T2 -dependence that is consistent with band structure predictions of a reduction in the density of states, correlated with sharp features near the Fermi level. [Display omitted] [ABSTRACT FROM AUTHOR]

Single crystals of high concentration iron substituted Sm 0.55 Sr 0.45 Mn 0.4 Fe 0.6 O 3 were grown by optical floating zone technique in oxygen atmosphere. Analysis of powder X-ray diffraction and Laue patterns revealed single-phase formation and crystal quality respectively. Replacement of Mn by iron has reduced the ratio of trivalent to tetravalent Mn ions thus suppressing the double exchange interactions and ferromagnetism. The grown crystal exhibits spin glass behavior below 35 K due to the competition between the Mn 3+ -O-Mn 4+ double exchange and the Mn 3+ -O-Fe 3+ super exchange interactions. [ABSTRACT FROM AUTHOR]

A film containing three dimensional Bi 2 S 3 nanowires network was obtained using Bi(NO 3 ) 3 and thioacetamide as starting materials through three steps, namely the chemical synthesis of Bi 2 S 3 , preparation of its sol under ultrasonic condition and crystal self-assembly at 25 °C. The nanowires had diameters of 20–100 nm. The formation mechanism of the 3D nanowires network is the anisotropic growth of Bi 2 S 3 . The sensor based on 3D Bi 2 S 3 nanowires network with an excellent response to ammonia at 30 °C. The response mechanism of the sensor for ammonia is a weak coordination adsorption of ammonia molecule on the Bi 2 S 3 nanowires and the electron is partially transferred from ammonia molecule to bismuth (III) ion. The maximum response of the sensor to ammonia was up to 82.3 and had a good linear range from 30 to 350 ppm concentration, indicating its potential applications in the determination and leak alarm of ammonia. [ABSTRACT FROM AUTHOR]

In the article, we propose a simple and effective one-pot hydrothermal approach for synthesis of raspberry-like ZnO microspheres, where triblockpoly (ethylene oxide)-poly (propylene oxide)-poly (ethylene oxide), triethanolamine, ethylene glycol acts as the structure-directing agent (SDA), co-template, and solvent, respectively. They are together responsible for the growth of ZnO products with uniform morphology, high crystallinity, and good monodispersity. The resulting ZnO microspheres possess rough surface, which are composed of many small nanoparticles. Moreover, the surface roughness and the diameter of the microspheres can be easily tuned only by changing the composition of the precursor. Meanwhile, the photodegradation behavior of the products is also tested by selecting the rhodamine B (RhB) as the model pollutant. The photocatalytic results indicate that the raspberry-like ZnO products exhibit excellent photocatalytic activity. In particular, the Au decorated-ZnO composite demonstrates an enhanced photocatalytic activity towards degradation of RhB under UV irradiation compared with the pristine ZnO microspheres. [ABSTRACT FROM AUTHOR]

This study is focused on the investigation of the electrical conductivity of sodium lithium magnesium silicate (Na hectorite) dispersion, which was hydrothermally synthesized from the brine of the Qarhan Salt Lake. Depending on the duration of the utilized hydrothermal treatment procedure, porous hectorite samples with tunable aspect ratios ranging from 70 to 500 were produced from the delaminated specimens stacked along the c -axis. More, benefiting from the appearance and enlarged size of these stacked layers, the as-prepared Na hectorites obtained at 180 °C for longer than 96 h own the average conductivities in excess of ×10 −4 S/cm when the concentrations are higher than 1.25 mg·mL −1 , which is largely influenced by their size, crystallinity and aspect ratio. [ABSTRACT FROM AUTHOR]

Dodecahedral SmVO 4 nanocrystals with uniform size had been successfully synthesized by a facile hydrothermal process in the presence of potassium hydroxide and urea. The dodecahedron-like SmVO 4 was characterized by X-ray diffraction, field-emission scanning electron microscopy, Fourier transform infrared, X-Ray photoelectron spectroscopy, high-resolution transmission electron microscopy and photoluminescence. The possible growth mechanism of the SmVO 4 nanocrystals with dodecahedral shape was discussed. Under excitation at 315 nm, the SmVO 4 sample exhibits strong orange emission while it as the host doped with suitable amount of Eu 3+ ions shows strong reddish orange emission. The diversity in emission intensity detected from SmVO 4 : x% Eu 3+ (x = 1, 3, 5, 7) was compared. The hydrothermal method for preparing dodecahedral SmVO 4 nanocrystals provides us an idea to synthesize other rare earth orthovanadate nanomaterials with special morphology and interesting optical property. [ABSTRACT FROM AUTHOR]

Indium nitride (InN) thin films grown on aluminum nitride on p-type silicon (111) [AlN/p-Si(111)] substrates are prepared via sol–gel spin coating method followed by nitridation. The thermal decomposition effects of ammonia (NH 3 ) gas on the structural properties and surface morphologies of the deposited films are investigated. X-ray diffraction results reveal that the crystalline quality of InN degrades markedly as thermal decomposition of NH 3 gas increases from 700 to 850 °C, at which indium oxide (In 2 O 3 ) forms in the deposited films. The thermal etching effect and formation of indium droplet on the film are observed at 850 °C. These findings are consistent with those of elementary and cross-sectional analysis obtained through energy dispersive spectroscopy and field-emission scanning electron microscopy. The findings deduced that InN thin films with densely packed grains can be grown at NH 3 decomposition temperature of 700 °C. [ABSTRACT FROM AUTHOR]

The 3D hierarchical microstructured electrodes by assembling the individual 1D/2D nanosubunits can fully take advantage of the merit of 1D/2D nanostructured materials, as well as alleviate their drawbacks. In this work, SnS 2 3D hierarchical microcubes consisting of 2D nanosheet subunits were facilely synthesized via a simple topotactic transformation with room-temperature coprecipitated ZnSn(OH) 6 microcubes as the template. Compared to bulk counterparts, this microstructured SnS 2 was found to have a unique morphology and electrochemical interfacial regions that facilitated highly efficient Li-ion insertion/extraction and effectively accommodate the large volume changes during charge/discharge cycles. Over the whole 200 cycles at 1C current density, an outstanding cycleing stability is exhibited, with a high stable specific capacity of about 640 mA h g −1 . [ABSTRACT FROM AUTHOR]

Four kinds of morphologies of Eu 3+ doped indium borate of the InBO 3 phosphors have been prepared via a facile flux method only by adjusting the kinds of reaction boron source materials, which have been characterized by XRD, EDS and SEM. In addition, the doping concentration also has a great influence on the morphology of samples. Furthermore, the luminescence properties of the prepared InBO 3 :Eu 3+ samples have been investigated by photoluminescence (PL) spectra. The results show that the fluorescence performance is strongly correlated with morphologies. The prepared InBO 3 :Eu 3+ phosphors show strong orange emissions under ultraviolet excitation at 237 nm, in which the monodisperse octahedra sample prepared with K 2 B 4 O 7 ·4H 2 O as the boron source and Eu 3+ doping concentration being 5% possesses the higher PL intensity and color purity, which can be used as a potential orange luminescent material. [ABSTRACT FROM AUTHOR]

The fabrication of rare earth luminescent materials with monodispersed and hierarchical morphology is of great importance due to their various applications. In this report, monodispersed hierarchical Yb(OH) x F 3−x microcrystals assembled by nanorod arrays were synthesized by a mild hydrothermal route. Calcination of Yb(OH) x F 3−x resulted in the formation of Yb 6 O 5 F 8 with the retention of morphology. The crystallographic structure relationship between Yb(OH) x F 3−x and Yb 6 O 5 F 8 and the transformation mechanism from Yb(OH) x F 3−x to Yb 6 O 5 F 8 were disclosed. The upconversion emission properties of the Er 3+ doped samples were investigated. It can be found that Yb 6 O 5 F 8 : 5%Er 3+ exhibited an intense red light upconversion emission with the strongest peaks around 658 nm while Yb(OH) x F 3−x : 5%Er 3+ shows no upconversion emission. [ABSTRACT FROM AUTHOR]

The hierarchical porous bismuth tungstate (Bi 2 WO 6 ) microcoins constructed by nanoplates have been successfully fabricated via a facile hydrothermal method with the assistance of nitrilotriacetic acid (NTA). X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were carried out to investigate the influences of NTA content on the morphology and microstructure of Bi 2 WO 6 . The results demonstrated that NTA has significant effect on the diameter and morphology of Bi 2 WO 6 . When the content of NTA is 0.8 g, Bi 2 WO 6 exhibited a hierarchical porous coin-like structure that consisted of numerous interconnected nanoplates with the diameter of approximately 50 nm. The corresponding growth mechanism also has been proposed and discussed. Moreover, due to the unique hierarchical porous structure and narrow band gap energy, Bi 2 WO 6 with 0.8 g NTA sample exhibited the superior photocatalytic activity to the degradation of Rhodamine B (RhB) under visible-light irradiation. [ABSTRACT FROM AUTHOR]

Ga 2 O 3 crystals doped with nominally 1% ns 2 ions (In, Tl, Sn, Pb, Sb and Bi) were synthesized by the Floating Zone (FZ) method, and we systematically evaluated the optical and scintillation properties. The peak emission was observed around 2.8 eV in photoluminescence (PL) under the excitation energy of 4.68 eV and around 3.0 eV in scintillation under X-ray irradiation. The PL and scintillation decay times were approximated by a sum of three exponential decay functions; and the derived decay times ranged several tens of nanoseconds, hundreds of nanoseconds and several microseconds. The slowest component was ascribed to the nsnp-ns 2 transitions while the fastest and intermediate components were blamed for the defect-related emission. Among the present samples, Sn-doped Ga 2 O 3 showed the highest scintillation light yield. [ABSTRACT FROM AUTHOR]

This paper reports the synthesis of ZnO nanostructures (nano-bullets, nanorods, nanospheres) by a facile and novel modified polyol method without surfactants, varying only the molar concentration of precursor salt (Zinc acetate dihydrate) using ethylene glycol and deionized water. At a constant temperature of 160 °C, nano-bullets were obtained at a concentration of 0.6 M, whereas at 0.8 M nanorods were observed while at 1.0 M only nanospheres appear. X-ray Diffraction, Scanning Electron Microscopy, High-Resolution Transmission Electron Microscopy and Room-Temperature Photoluminescence properties were used to characterize the nanostructures. Based on the results it is suggested a high dependence between morphology and molar concentration of the precursor salt as well as a mechanism of crystallization of the different nanostructures. The nanostructures may be used to produce optoelectronic devices. [ABSTRACT FROM AUTHOR]

The preparation of In 2 O 3 crystals in phase separated structure of sodium borosilicate (Na 2 O-B 2 O 3 -SiO 2 ) glass was successfully obtained by melt quenching method and its electrical conductivity was successfully clarified. Sodium borosilicate glass is phase separated into silica (SiO 2 ) phase and sodium borate phase (Na 2 O-B 2 O 3 ). The sodium borate phase mainly contains ionic bondings, and the generation and growth of crystals can easily occur in this phase for its high solubility of various kinds of ions. In this study, a glass ceramics was prepared by precipitating In 2 O 3 crystals in the sodium borate phase of the sodium borosilicate glass. After acid leaching of the sodium borate phase, the In 2 O 3 X-ray diffraction peaks that were observed after crystallization treatment disappeared, indicating that In 2 O 3 crystals were selectively precipitated in the sodium borate phase. By decreasing the proportion of the sodium borate phase which was achieved via controlling the amount of B 2 O 3 in the glass, In 2 O 3 crystals precipitated continuously in this phase, resulting in an increase in the electrical conductivity from 3.30 × 10 −5 S/cm to 6.56 × 10 −5 S/cm at 500 °C and a decrease in the activation energy from 36.6 kJ/mol to 27.0 kJ/mol, respectively. Furthermore, the electrical conductivity increased by Sn doping and introduction of oxygen vacancies via H 2 reduction into the In 2 O 3 crystal lattice. [ABSTRACT FROM AUTHOR]

GaS 0.75 Se 0.25 single crystals were optically characterized through transmission and reflection measurements in the wavelength range of 450–1000 nm. Derivative spectrophotometry analyses on temperature-dependent transmittance spectra showed that band gap energies of the crystal increase from 2.39 eV ( T = 300 K) to 2.53 eV ( T = 10 K). Band gap at zero temperature, average phonon energy, electron phonon coupling parameter and rates of change of band gap energy with temperature were found from the temperature dependences of band gap energies under the light of different models reported in literature. Furthermore, the dispersion of room temperature refractive index was discussed in terms of single effective oscillator model. The refractive index dispersion parameters, namely oscillator and dispersion energies, zero-frequency refractive index, were determined as a result of analyses. [ABSTRACT FROM AUTHOR]

Mechanochemical-hydrothermal synthesis is a low-cost and efficient method to prepare functional particles, due to the local high-pressure and high-temperature reaction fields generated during the process. Here, mechanochemical-hydrothermal synthesis of layered lithium titanate hydrate, Li 1.81 H 0.19 Ti 2 O 5 · x H 2 O (LHTO), using a planetary ball mill is demonstrated. By planetary ball milling of LiOH and TiO 2 with water at room temperature, LHTO nanotubes with lengths over 300 nm were synthesized. The synthesized LHTO nanotubes were transformed to Li 4 Ti 5 O 12 (LTO), which is a common anode material for Li-ion batteries, via thermal treatment while maintaining the nanotube morphology. The anode properties of the thermally prepared LTO nanotubes exhibited a first discharge capacity of 160 mAh/g at a rate of 0.1 C, even though residual TiO 2 and contamination from ZrO 2 milling balls were observed as product impurities. The reduction of impurities in the product after mechanochemical-hydrothermal synthesis is important to improve material performances. [ABSTRACT FROM AUTHOR]

Ho 3+ /Yb 3+ co-doped Bi 2 WO 6 (Ho 3+ /Yb 3+ -Bi 2 WO 6 ) nanopowders were synthesized by a simple hydrothermal method. Crystal structure, morphology and chemical composition of the samples were characterized by XRD, SEM, TEM and EDS. The effects of some critical synthesis conditions on the upconversion luminescence properties were studied in detail. Under the excitation of 980 nm laser diode, Ho 3+ /Yb 3+ -Bi 2 WO 6 upconversion nanopowder with strongest luminescence intensity was obtained when the concentration of Ho 3+ and Yb 3+ were 1 mol%, 5.0 mol% respectively, and calcined at 600 °C. Moreover, excitation power studies showed that a two-photon process was involved in the upconversion emissions. The probable upconversion luminescence mechanism was discussed according to the energy transfer process. [ABSTRACT FROM AUTHOR]

Transition metal compounds with quasi-two-dimensional structure demonstrate a series of un-precedent quantum phases, such as topological insulator, topological phase transition under thermal/pressure stimuli, which is attributed to delicate interplay among interlayer coupling, spin-orbit coupling and stoichiometry. Here, Cu 2 TlSe 2 and Cu 2 TlTe 2 crystals were successfully synthesized by Bridgeman method. Highly crystalline quality of these samples is verified by X-ray diffraction and microstructural characterization. Temperature-dependent-Hall-resistivity shows that Cu 2 TlSe 2 is hole-like and Hall resistivity is in-sensitive to temperature; while Hall resistivity of Cu 2 TlTe 2 is positive at room temperature and change to negative at 30 K. Combined experimental results and electronic band structures calculated by first-principles method, it is revealed that Cu 2 TlSe 2 is a metal, but Cu 2 TlTe 2 is a semi-metal. This work demonstrates the rich physical phases of layered transition metal compounds under the interplay among interlayer coupling, spin-orbit coupling and stoichiometry. [ABSTRACT FROM AUTHOR]

We report the observation of quantum Hall effect (QHE) in a Bi 2 Se 3 single crystal having carrier concentration ( n ) ∼ 1.13 × 10 19 cm −3 , three dimensional Fermi surface and bulk transport characteristics. The plateaus in Hall resistivity coincide with minima of Shubnikov de Haas oscillations in resistivity. Our results demonstrate that the presence of perfect two dimensional transport is not an essential condition for QHE in Bi 2 Se 3 . The results of high resolution X-ray diffraction (HRXRD), energy-dispersive X-ray spectroscopy (EDX), and residual resistivity measurements show the presence of enhanced crystalline defects and microstrain. We discuss the possible origin of the observed QHE and correlate its existence to the crystalline defects. [ABSTRACT FROM AUTHOR]

Defects distribution in ZnO nano-particles is introduced by high temperature annealing in air and corresponding visible emission are comprehensively analyzed. Grain size initially increases with increasing annealing temperature until 800 °C and decreases after that. Higher temperature annealing alters defect distribution and initiates formation of O Zn (Zinc at oxygen site). Formation of O Zn , and presence of conventional defects is confirmed by Electron Paramagnetic Resonance spectra. Spatial distribution of polychromatic emission centers in annealed sample is estimated by diffusion mediated growth and confirmed by florescence imaging. Blue emission centre is found to be located on surface of particle/grain which gets modified by surface capping using PEG and PVA. These visible emissions exhibit strong excitation dependence, and can be excited below the bad gap energy. Based on XRD, EPR, emission by low energy excitation, and florescence imaging schematic of defect distribution within particle/grain and their corresponding emission is proposed. [ABSTRACT FROM AUTHOR]

GaAs 1−x N x /GaAs multiple quantum wells (MQWs) were grown on GaAs(001) substrates through solid-source molecular beam epitaxy under various nitrogen background pressures (NBPs), and the crystal quality at the interface of GaAs 1−x N x and GaAs was investigated. X-ray diffraction and electron microscopy confirmed the low interface roughness of MQWs grown at a NBP of 5 × 10 −6 Torr. Surface morphology measurements revealed a smooth surface without whisker-like defect structures. The fabricated MQWs exhibited high photoluminescence intensity because of the reduction in surface recombination with high nitrogen incorporation. Raman spectroscopy confirmed the presence of N-like local vibrational mode, and this was attributed to the presence of phase separation in GaAsN alloys. Rapid thermal annealing improved photoluminescence intensity by 100-fold and substantially reduced full width at half maximum because of MQW homogenization. These results evidence the favorable crystal interface of GaAs 0.978 N 0.022 alloys. Hence, GaAs 0.978 N 0.022 /GaAs MQWs grown under high pressure might be useful in fabricating optoelectronic devices. [ABSTRACT FROM AUTHOR]

• Si 3 N 4 and Sb are used to construct multi-layer materials to adjust the phase change performance and crystallization behavior of Sb films for the first time. • The Sb film covered by Si 3 N 4 has better thermal stability, better data retention and higher crystallization rate. • The low element diffusion between Sb and Si 3 N 4 helps stabilize the nano-interface between Sb and Si 3 N 4 and improves resistance drift. • Multilevel resistance can be achieved by tunning the crystallization mechanism. Phase change materials (PCMs) have been attracting increasing interest in computer bionics and artificial intelligence neuron systems. However, the influence of interface between Si 3 N 4 and PCMs on phase chang behavior is still unclear. In this paper, phase change performance and crystallization behavior of homogeneous Sb film are adjusted by changing the thickness of the Si 3 N 4 film and the iteration period. Sb film covered by Si 3 N 4 has better thermal stability, better data retention, and higher crystallization rate due to that the stable Si 3 N 4 can reduce the long-range order and inhibit the nano-size growth of Sb crystal grains. The low element diffusion between Sb and Si 3 N 4 is favorable to stabilize the nano-interface and significantly improve the resistance drift. The resistance polymorphism including high, intermediate, and low resistance states can be obtained by annealing at different temperatures. The ability to achieve such a multilevel resistance state is ascribed to the nucleation-dominated crystallization mode. [Display omitted] [ABSTRACT FROM AUTHOR]

Gallium zinc oxynitride powder and its nanocrystals were obtained by nitridation of a ZnGa 2 O 4 precursor under NH 3 flow. The nitrided powder had the chemical composition of (Ga 0.75 Zn 0.23 □ 0.02 ) (N 0.71 O 0.29 ), where □ indicates a vacancy, and showed improved crystallinity with a decrease in cationic vacancies compared to that for pristine gallium oxynitride without zinc. Gallium zinc oxynitride nanocrystals with rod-like morphology were obtained by nitridation of the oxide precursor on a NiO pellet. The nanorod crystals were several hundred nanometers wide and several micrometers long. The nanorods had a sawtooth appearance with triangular grains aligned along the length direction of the rods. The nanocrystals with a chemical composition of Ga/Zn = 0.80/0.20 exhibited a broad cathodoluminescence emission at 2.1 eV, similar to the powder products. [ABSTRACT FROM AUTHOR]

Upconversion phosphors composed of both gray-white and gray-black microcrystals were synthesized using a facile hydrothermal route. The microcrystals with different contrast in the SEM images were confirmed to be Y-based and Sc-based microcrystals by SEM, XRD, EDX and elemental mapping. The morphology evolution of Y-based microcrystal induced by Sc 3+ co-doping can be ascribed to the variation of anisotropic growth for different crystal planes. We studied the dependence of fluorescence intensity on pump power and investigated the variation of fluorescence decay dynamics for the different compositions. It was found that an increase of the energy transfer rate from Yb 3+ to Er 3+ , Ho 3+ , Eu 3+ and Tm 3+ , and a decrease of the phonon energy by Sc 3+ co-doping were responsible for the observed fluorescence tuning. Such a simultaneous morphology evolution and upconversion fluorescence tuning of single Y-based fluoride microcrystal with low phonon energy will show a great potential in microlaser, photovoltaics, and photo-communication. [ABSTRACT FROM AUTHOR]

A preliminary e-beam exposure of the substrate is found to strongly affect the process of further chemical vapor deposition (CVD). It is known that e-beam exposure can cause charging of dielectric films and a part of the charge remains in the film after exposure. However the accumulated charge has never been used to control the rate of CVD. In this work such a control is illustrated for the first time by a selective graphene-like films deposition on silicon dioxide. It is shown that the influence of substrate exposure on the graphene-like films growth is not related to carbon contamination, which can be formed on the sample surface in scanning electron microscope during electron exposure. The results suggest that the selective growth of graphene-like films on an irradiated SiO 2 /Si substrate is a promising approach to producing a microstructure at the pre-synthesis step without involving a full lithography process. [ABSTRACT FROM AUTHOR]

BiVO 4 as one of the promising visible-light-driven photocatalysts attracted considerable research on morphology and composition control. In this work, a modified carbonaceous spheres sacrificial template growth technique are developed to build up multi-shell hollow spheres of the heterostructured Bi–V–O. By treating the carbonaceous spheres with NaOH aqueous, the simultaneous adsorption of Bi 3+ and VO 3 − are achieved successfully, and through the precisely controlled calcination, the nanoparticles of BiVO 4 and Bi 4 V 2 O 11 are crystallized and interconnected into the Bi–V–O heterostructured multi-shell hollow spheres. These Bi–V–O hollow spheres demonstrate a high visible-light-driven photocatalytic activity towards the decomposition of Methylene blue, and the double-shell one with the highest Bi 4 V 2 O 11 content shows the best photocatalytic activity. The high photocatalytic activity may due to the effective utilization of visible light induced by multiple reflections of their special multi-shell hollow spheres. The heterostructure between BiVO 4 and Bi 4 V 2 O 11 may also make a contribution to the enhanced photocatalytic activity. [ABSTRACT FROM AUTHOR]

Novel ZnO combined structures were obtained using the radio frequency (RF) sputtering method. The effects of two different substrates, Si and 128° YX LiNbO 3 , on the structural, morphological, and optical properties of ZnO films were investigated. Field emission scanning electron microscopy clearly revealed the formation of a mixed flake-corolla lobe-like structure. The grain size of the obtained structure depended on the substrate type. Two different X-ray diffraction peaks were obtained for ZnO growth on LiNbO 3 , at the (200) and (201) diffraction planes, respectively. [ABSTRACT FROM AUTHOR]