CdS-ZnO composite nanorods: Synthesis, characterization and application for photocatalytic degradation of 3,4-dihydroxy benzoic acid

Well-aligned arrays of CdS-ZnO composite nanorods were grown on indium tin oxide substrates. ZnO nanorods, deposited by a low temperature aqueous chemical growth technique, were dip coated with CdS. The CdS-ZnO nanorods were polycrystalline as confirmed from the low angle X-rays diffraction study. Photon to current conversion efficiency of CdS-ZnO composite nanorod was observed to be higher than that of CdS. In the micro-Raman spectrum, we observed longitudinal optical modes of CdS and ZnO showing their co-existence. The appealing application of CdS-ZnO nanorod as a visible photocatalyst was demonstrated and the possible mechanism was discussed.     

Interaction of loosely bound radioactive 7Be and stable 7Li with 9Be

Quasielastic scattering angular distributions have been measured for the ⁷Be + ⁹Be system at E _lab = 17 , 19 and 21MeV in the angular range $ \theta_{{cm}}^{}$ = 24^° - 57^° . An optical model (OM) analysis of these data has been carried out in order to extract optical potential parameters and reaction cross-sections. One-proton stripping cross-sections were also measured for this system at E _lab = 19 and 21MeV. These transfer angular-distribution data were compared with the finite-range distorted-wave Born approximation (FRDWBA) calculations. For the ⁷Li + ⁹Be system quasielastic scattering angular distributions were measured and emitted light charged particles were detected at E _lab = 15.75 , 24.00 and 30.00MeV in the angular range $ \theta_{{cm}}^{}$ = 7^° - 70^° . Fusion cross-sections were obtained by reproducing the measured $ \alpha$ -evaporation spectra from the compound nucleus at backward angles with the statistical model calculations. The ratios of the experimental fusion cross-sections to the total reaction cross-sections (obtained from OM analysis) were found to be small. This result suggests that the break-up process has a strong influence on the fusion process leading to a reduction in the fusion cross-section.     

Defect driven multiferroicity in Gd doped BiFeO3 at room temperature

This paper reports that defect driven magnetism can be obtained at room temperature by optimizing metal ion concentration in bismuth ferrite (BFO) following our novel slow step solid state sintering route. We observed a clean signature of enhanced multiferroic behavior in Gd doped bismuth ferrite (Gd-BFO) bulk ceramics at room temperature (RT). Bismuth rich iron deficient Gd-BFO ceramics were prepared by solid state route through slow step sintering schedule at 850 °C. At particular composition, (Bi_1.2Gd_0.1Fe_0.8O₃), this materials completely transform from rhombohedral R3c to orthorhombic Pn2₁a space group. We emphasized that excess bismuth is expected to act as point defects and occupy interstitials positions, which in turn interact by oxygen vacancies. These defects are likely to promote defect driven ferromagnetism in BFO system. Incorporation of Gd in presence of excess bismuth in BFO enhanced both spin and electric polarization at room temperature. We also infer that Gd substitution in BFO is likely to suppress spiral spin modulation, which also favors ferromagnetism in Gd-BFO.     

Application of radioisotopes in the field of nuclear medicine

A comprehensive review has been made to discuss the role of various radionuclides of lanthanide series elements in the field of nuclear medicine. The role of several pharmaceuticals labeled with radiolanthanides and used for investigative purposes like measurement of cerebral blood flow, bone density measurement, bone marrow imaging, etc., have been described. The role of lanthanide radionuclides in radiation synovectomy, radioimmunotherapy, etc., have also been discussed. Methods of preparation of some representative radiopharmaceuticals like¹⁵³Sm-EDTMP,¹⁵³Sm-HYP, have been presented. An outline on the production of carrier free radioisotopes of lanthanide series elements has been given.     

Kinetics and products of propargyl (C3H3) radical self‐reactions and propargyl‐methyl cross‐combination reactions

Propargyl (HCC CH₂) and methyl radicals were produced through the 193‐nm excimer laser photolysis of mixtures of C₃H₃Cl/He and CH₃N₂CH₃/He, respectively. Gas chromatographic and mass spectrometric (GC/MS) product analyses were employed to characterize and quantify the major reaction products. The rate constants for propargyl radical self‐reactions and propargyl‐methyl cross‐combination reactions were determined through kinetic modeling and comparative rate determination methods. The major products of the propargyl radical combination reaction, at room temperature and total pressure of about 6.7 kPa (50 Torr) consisted of three C₆H₆ isomers with 1,5‐hexadiyne(CHC CH₂ CH₂ CCH, about 60%); 1,2‐hexadiene‐5yne (CH₂CC CH₂ CCH, about 25%); and a third isomer of C₆H₆ (∼15%), which has not yet been, with certainty, identified as being the major products. The rate constant determination in the propargyl‐methyl mixed radical system yielded a value of (4.0 ± 0.4) × 10⁻¹¹ cm³ molecule⁻¹ s⁻¹ for propargyl radical combination reactions and a rate constant of (1.5 ± 0.3) × 10⁻¹⁰ cm³ molecule⁻¹ s⁻¹ for propargyl‐methyl cross‐combination reactions. The products of the methyl‐propargyl cross‐combination reactions were two isomers of C₄H₆, 1‐butyne (about 60%) and 1,2‐butadiene (about 40%). © 2000 John Wiley & Sons, Inc. Int J Chem Kinet 32: 118–124, 2000     

Vanadium(IV)-oxo Corrole Catalyzed Selective Oxidative Cleavage of Alkenes to Aldehydes

A practical and efficient protocol for oxidative cleavage of olefinic bonds especially in arylated olefins has been demonstrated. Herein, an oxo[5,10,15-tris(4-nitrophenyl)corrolato]vanadium (IV) complex (cat.), has been successfully synthesized and the existence of two tautomeric forms of this complex in solution has been established. Oxo[5,10,15-tris(4-nitrophenyl)corrolato]vanadium (IV) (cat.) in the presence of H₂O₂ cleaves olefinic bonds to yield the corresponding aldehyde compounds. In general, a high valent, oxo-(porphyrinoid)-metal complex catalyzes the epoxide formation reactions, however, in the present case, we have observed the exclusive formation of aldehydes. The reaction offered aryl aldehydes with good yields and excellent selectivity. A mechanism was also proposed for these catalysis reactions.     

ChemInform Abstract: Equilibrium Geometry,Stability, and Magnetic Properties of Small MnO Clusters

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.