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Trigonal selenium nanoparticle is synthesized by precipitation method using three L-arginine concentrations and ascorbic acid and by varying aging time. In the XRD analysis, glassy nature of selenium is identified (pH ≈ 2.8) and turned into hexagonal stru

New modifications (denoted as β-) of the compounds H 2SeO3, NaHSeO4, and Na5H 3(SeO4)4(H2O)2 were isolated from aqueous solutions and their crystal structures determined from single crystal data. β-H2SeO3 crystallizes in the space group P1 with lattice parameters of a = 4.6794(4) A, b = 5.0988(4) A, c = 5.7743(5) A, α = 102.252(6)°, β = 91.594(6)°, γ = 98.054(6)°, and consists of two unique trigonal-pyramidal SeO(OH)2 units that are held together by O-H...O hydrogen bonds. β-NaHSeO4 crystallizes in the space group P1 with lattice parameters of a = 5.0814(2) A, b = 5.6345(3) A, c = 6.5125(3) A, α = 88.352(3)°, β = 73.163(3)°, γ = 82.027(3)°, and is made up of distorted NaO 6 octahedra and tetrahedral SeO3(OH)- anions, with the hydrogen atom statistically disordered between two positions. β-Na5H3(SeO4)4(H 2O)2 crystallizes in the space group I2/c with lattice parameters of a = 7.0472(15) A, b = 13.194(3) A, c = 17.845(4) A, β = 101.345(9)°. The asymmetric unit contains three Na + sites (one situated on a twofold rotation axis and each with a distorted octahedral coordination by oxygen atoms), one water molecule, one SeO3(OH)- anion, and half of an [SeO 4...H...O4Se] unit with a very short interpolyhedral O...O distance of 2.447 (4) A. The crystal structures of the β-modifications are comparatively discussed with those of the corresponding known α-modifications. Moreover, the crystal structure of Te2O4(OH)2 was reinvestigated [Pna2 1, a = 12.0512(8) A, b = 8.0267(5) A, c = 4.7268(3) A], allowing the localization of the hydrogen atoms and hence a more detailed view of the hydrogen bonding system. Copyright

In contrast to the layered structure of the previously known polymorph of copper diselenite, the crystal structure of a new polymorph, β-CuSe2O5, is based on a 3D framework and has a higher structural complexity than the α-phase.

In this work, we report a novel electrochemical technique to prepare band gap engineered IV-II-VI type ternary solid solution system of Pb xCd1-xSe. This technologically important material is prepared using this method for the first time. We have used a self sufficient modified electrochemical cell made up of Pb anode and a transparent conducting oxide (TCO) coated glass cathode, containing Pb(CH3COO)2, Cd(CH3COO)2, H2SeO3 and Na 2EDTA solutions with proper concentrations as the working electrolyte. X-ray diffraction (XRD) pattern analysis confirms the formation of highly crystalline PbxCd1-xSe, whereas, scanning electron micrograms (SEM) reveals a uniform deposition with compact surface morphology. This ternary system showed band gap energy (Eg) of about 1.4 eV, which is in between CdSe ( 1.77 eV) and PbSe (0.3 eV) and reasonably good for solar energy absorption. Good rectifying behaviour of the TCO/ Pb xCd1-xSe hetero-junction was established from the current-voltage measurements, which indicate the p-type conduction nature of the deposited ternary compound. Mechanical properties of such thin films were measured by nano-indentation.

The present invention relates to means and methods for producing crystals or crystalline substances. In particular, crystals or crystalline substances which are useful as pharmaceutical ingredients can be manufactured.

A facile method for the preparation of Te- and Se/Te-doped anatase TiO 2 nanorods (NRs) with exposed {100} facets, which provides high photocatalytic and antibacterial activity under irradiation with visible light, is developed. Sodium titanate nanotubes are formed from commercial TiO 2 nanoparticles (P25) in NaOH through a hydrothermal reaction. The as-prepared Na-titanate nanotubes are then used to form Te-TiO2 nanotubes in the presence of tellurite (TeO32-) ions and NaBH4. Upon further hydrothermal reaction, the Te-TiO2 nanotubes are transformed to form Te-TiO2 NRs that further form Sen/Te-TiO2 NRs through a reduction of selenite (SeO 32-) ions with NaBH4. The Te-TiO2 NRs and Sen/Te-TiO2 NRs have highly active {100} facets and thus provide the photocatalytic activities for the generation of ×OH at 2.5 and 4.5 times higher than that of commercial P25, respectively. The Te-TiO2 and Sen/Te-TiO2 NRs exhibit higher antibacterial activities against E. coli and S. aureus than P25 when activated by visible light. These stable and biocompatible Te-TiO2 and Se n/Te-TiO2 NRs hold great potential as potent antibacterial agents.

In the present study, we report the room temperature electrosynthesis of Zinc selenide (ZnSe) thin films on stainless steel (SS) and fluorine doped tin oxide (FTO) coated glass substrates. In addition, the influence of the substrate on the microstructural

The solution enthalpies have been determined for the ternary phases RE2SexO3+2x existing on the pseudo-binary section RE2O3-SeO2 and for RE2O3 and SeO2 in 4

Raman spectroscopy has shown that the initial stages of haloselenate(IV) formation equilibria are the same in HF and HCl solutions. The constants K4 and K5, evaluated by quantitative Raman measurements, for HCl solutions are 0.015 (+/- 0.001) L2mol-2 and 0.9 (+/- 0.1)E-5 L2mol-2, respectively.These constants yield the minimum average deviation in normalized molar scattering intensity for the species formed in three regions of the spectra, 690 and 890 cm-1 (SeO stretching) and 100-450 cm-1 (deformation and SeCl stretching).Before the oneset of haloselenate(IV) formation, changes in the SeO stretching band intensities with HX concentrations occur due to repression of ionic dissociation of selenious acid Quantitative Raman measurements yield K1 = 9.8 (+/- 0.3)E-3 mol L-1.Reasons for the high value of this constant, compared to reported values, are discussed.