Degradation of rhodamine B photocatalyzed by Eu-doped CdS nanowires illuminated by visible radiation

CdS nanowires doped with different contents of Eu dopant were synthesized by solvothermal method. XRD, SEM, TEM and Raman analyses certified that the as-synthesized samples were hexagonal CdS uniform nanowires. The pure CdS nanowires were 1–3 ?μm long and 80 ?nm diameter with the 1st and 2nd order longitudinal phonon modes at 298 and 594 ?cm^?1. The 3% Eu-doped CdS wires were 800 ?nm–2.5 ?μm long and 75 ?nm diameter with the 1st and 2nd order longitudinal phonon modes at 296 and 593 ?cm^?1. CdS nanowires grew along the [001] direction due to the surface energy effect. The photocatalytic properties of CdS and Eu-doped CdS nanowires were investigated for the degradation of rhodamine B (RhB) illuminated by visible radiation. In this research, Eu dopant played the role in promoting the photocatalytic kinetics because Eu³⁺ ions act as an electron acceptor to promote charge separation and photocatalytic activity. Both ^●OH and ^●O₂^? were the main active radicals used to transform RhB molecules into CO₂, H₂O and other intermediates.     

Combined magnetic and single-crystal X-ray structural study of the linear chain antiferromagnet [(CH3)4N][MnCl3] under varying pressure

The magnetic susceptibility and single-crystal X-ray structure of the one-dimensional Heisenberg antiferromagnetic chain tetramethylammonium manganese trichloride (TMMC) have been studied under pressure as a facile route to develop structure-property relationships. The X-ray structure of TMMC was determined at 0, 2.1, 3.8, 6.8, 12.2, and 17.0 kbar using diamond-anvil cell techniques and synchrotron radiation. The space group is confirmed to be P6(3)/m up to 17 kbar, and structural refinement shows that the Mn-Mn separations between and along the chains change by about 3.4 and 2.5%, respectively, over 17 kbar. A structural transition from hexagonal to monoclinic symmetry possibly occurs at 17 kbar, associated with a loss of crystal quality. Variable-temperature magnetic susceptibility data were taken at 0, 0.3, 1.5, 2.9, 4.0, 5.2, and 6.5 kbar and show that the intrachain coupling constant changes from -6.85 to -7.81 K over this range. The interchain coupling constant of -0.54 K can also be extracted from the Fisher model modified for interacting chains. The pressure-temperature diagram shows the slope of the intrachain antiferromagnetic coupling with pressure, DeltaT(IAF)/DeltaP, changes from 0.5 to 1.6 K/kbar at 2 kbar where the structure changes from P2(1)/a to P2(1)/m. Comparison of the magnetic and structural data are consistent with the power-law relationship developed by Bloch where J proportional, variant r-n, r = Mn...Mn separation and n approximately 10.     

19-nor-11-Oxooleanan-12-ene and 18,19-seco-19-oxours-11,13(18)-diene triterpenes from Diospyros decandra bark

Four new triterpenes, 2α,3β-dihydroxy-19-nor-11-oxo-20-dimethylurs-12-en-24,28-dioic acid (equivalent to 2α,3β-dihydroxy-19-nor-11-oxoolean-12-en-24,28-dioic acid), 2α,3β-dihydroxy-18,19-seco-19-oxours-11,13(18)-dien-24,28-dioic acid, 2α,3β,19α-trihydroxy-11-oxours-12-en-24,28-dioic acid and 2α,3β,19α-trihydroxy-28-1′-β-d-[glucopyranosyl-(1″→6′)-glucopyranosyl]-urs-12-en-24,28-dioic acid were isolated from the methanol extract of the bark of Diospyros decandra as their acetate-methyl ester derivatives. The first two compounds represent the biosynthetic transformation products of 2α,3β,19-trihydroxyurs-24,28-dioic acid via oxidative rearrangement of ring E.     

Isomerization of n-Hexane Over Platinum Ion-Exchanged Zeolite Beta

Zeolite Beta was synthesized from appropriate gels and crystallized under the controlled temperature and pressurized conditions. For isomerization of n-hexane, platinum ion-exchanged zeolite Beta exhibited high activity and selectivity for 2,2-dimethylbutane (2,2-DMB), 2,3-dimethylbutane (2,3-DMB), 2-methylpentane (2-MP) and 3-methylpentane (3-MP). As high as 72% of n-hexane conversion and 98% of product selectivity were obtained at 250°C, 1600 h^–1 for 20 min on stream. The influences of reaction temperature and space velocity were also studied. Pt/H-Beta zeolite was recommended as one of the promising catalyst for n-hexane isomerization due to its high activity and stability. The combined effect of the stronger acidity possessed by H-Beta and the dehydrogenation role played by Pt was believed to be responsible for the good catalytic performance of Pt/H-Beta.     

Characterization of sp carbon produced by plasma deposition on gamma-TiAl alloys

Surfaces of two gamma-TiAl alloys, Ti-47%Al-2%Nb-2%Cr (MJ12) and Ti-47%Al-2%Nb-2%Mn + 0.8%TiB₂ (MJ47), were modified by acetylene plasma deposition at −3 kV bias voltage for 0.5-4 h. By using GIXRD and SAED, C (n-diamond), TiC, Al, AlTi, AlTi₂, AlTi₃, Al_0.64Ti_0.36 and Al₂Ti were detected on both alloys. Additional TiB₂ was detected on MJ47. XPS and Raman analyses revealed the presence of sp³ and sp² carbon deposited on the alloy surfaces with their binding energies of 283.9-284.8 eV for MJ12 and 283.9-285.0 eV for MJ47. Both sp³ and sp² contents were increased with the increase in the exposure times. The increasing rate of the first was less than that of the second, due to the stress developed in the films. Moiré fringe and crystallographic planes were detected using TEM. Knoop hardness of the deposited alloys, influenced by sp³ carbon, was increased with the increase in the exposure time. Those of MJ12 and MJ47 with 4 h deposition are 1.88 and 1.57 times of the corresponding untreated alloys, respectively.     

Influence of pH on the synthesis ZnO nanorods and photocatalytic hydrogen production from glycerol solution

Photocatalytic oxidation of glycerol at ambient conditions has been investigated with the use of Zinc oxide photocatalysts. Zinc oxide nanorods were prepared via a simple hydrothermal method using zinc nitrate and sodium hydroxide in the solution pH of 7, 8 and 9. The samples prepared in this way were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), Brunauer-Emmett-Teller (BET) and ultraviolet–visible spectroscopy (UV–vis). The pH of the solution is 7, the sample contains zinc hydroxide nitrate hydrated. When the pH of solution was adjusted to 8 and 9, the samples consisted of pure hexagonal wurtzite ZnO without impurity detection. The influence of solution pH on hydrogen formation was investigated. The wurtzite ZnO nanorods synthesized in a solution with pH 9 are considered promising photocatalysts for hydrogen production under xenon radiation.     

Quantum chemical investigation on structures of pyrrolic amides functionalized (5,5) single-walled carbon nanotube and their binding with halide ions

The structures of mono- and di-podal pyrrolic amides functionalized (5,5) single-walled carbon nanotubes (SWCNTs) and their complexes with fluoride, chloride, and bromide ions were obtained using the two-layered ONIOM(MO:MO) and density functional theory (DFT) methods. The binding energies between halide ions and all the receptors and their charge transfers were obtained using DFT method. The computational results indicate that the pyrrolic amide functionalized on the SWCNT affects to the density of state and energy gap of SWCNT. All the free receptors, mono-, di-podal pyrrolic amides and the functionalized SWCNT forming the strongest complexes were found.     

BiOX (X = Cl,Br, and I) Nanoplates Prepared by Surfactant-Free Microwave Synthesis and Their Photocatalytic Performance

Russian Journal of Physical Chemistry A - Bismuth oxyhalide (BiOX; X = Cl, Br, and I) nanoplates were successfully synthesized by microwave irradiation of surfactant-free aqueous solutions. X-rays...     

Correction to: Review on the recent progress in the preparation and stability of graphene-based nanofluids

Journal of Thermal Analysis and Calorimetry - Thermal behavior and smoke characteristics of glass/epoxy laminate and its foam core sandwich composite were comprehensively investigated using...     

Visible-light-driven photocatalysis of heterostructure Ag/Bi<Subscript>2</Subscript>WO<Subscript>6</Subscript> nanocomposites and their photocatalytic degradation of dye under visible light irradiation

Ag/Bi₂WO₆ nanocomposites were successfully synthesized by a combination of hydrothermal method and ultrasonic vibration. The phases, vibration modes, constituents and morphologies were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The visible-light-driven photocatalytic activitiy of 0–10 wt% Ag/Bi₂WO₆ samples was studied by determining the photodegradation of rhodamine B under xenon lamp. In this research, 10 wt% Ag/Bi₂WO₆ nanocomposites exhibit the highest efficiency and have the promising photocatalytic properties for waste water treatment.