Photochemical Mineralization of Europium, Titanium, and Iron Oxyhydroxide Nanoparticles in the Ferritin Protein Cage
摘要:
The Fe storage protein ferritin was used as a size-constrained reaction vessel for the photoreduction and reoxidation of complexed Eu, Fe, and Ti precursors for the formation of oxyhydroxide nanoparticles. The resultant materials were characterized by dynamic light scattering, gel electrophoresis, UV-vis spectroscopy, and transmission electron microscopy. The photoreduction and reoxidation process is inspired by biological sequestration mechanisms observed in some marine siderophore systems.
In this work, the polymeric precursor method Was used to obtain disordered Zn2TiO4 powders, either Undoped or doped with Sn4+, Cr3+ and V5+, to be applied its photoluininescent material. The characterization was undertaken by means of thermal analysis (TG and DTA), X-ray diffraction (XRD), infrared spectroscopy (IR) and photoluminescence (PL). Previous works stated that titanate octahedra containing a short Ti-O distance show efficient luminescence at roorn temperature if these octahedra are isolated from each other. In the present work, the phenomenon was observed in condensed octahedra, sharing edges. The room temperature PL noticed in undoped Zn2TiO4 had its intensity increased by the dopant addition-the increase was of about 300% for V5+ doping 400% for Cr3+ and 800% for Sn4+. (c) 2005 Elsevier Inc. All rights reserved.
Stereoselective Formation of Seven-Coordinate Titanium(IV) Monomer and Dimer Complexes of Ethylenebis(<i>o</i>-hydroxyphenyl)glycine
作者:Maolin Guo、Hongzhe Sun、Shailja Bihari、John A. Parkinson、Robert O. Gould、Simon Parsons、Peter J. Sadler
DOI:10.1021/ic990669a
日期:2000.1.1
carboxylate O-atoms at 2.061(2) A, and a water molecule (Ti-OH2, 2.091(3) A). Complex 2 crystallizes as an oxygen-bridged dimer in the triclinic space group P-1 with a = 12.521(6) A, b = 14.085(7) A, c = 16.635(8) A, alpha = 80.93(2) degrees beta = 69.23(2) degrees, gamma = 64.33(2) degrees , V = 2472(2) A3, Z = 4, and R(F) = 0.0580 for 5956 independent reflections having I > 2sigma(I). Each seven-coordinate
Grain size dependent magnetoelectric coupling of BaTiO<sub>3</sub> nanoparticles
作者:Tesfakiros Woldu、B. Raneesh、M. V. Ramana Reddy、Nandakumar Kalarikkal
DOI:10.1039/c5ra18018j
日期:——
We report the magnetoelectric (ME) coupling properties of BaTiO3 nanoparticles of different grain sizes ranging from 16–26 nm synthesized using a modified Pechini method.
The crystal structure of dielectric ceramics in the (1 - x)La2MgTiO6 (LMT)-xBa(2)MgWO(6) (BMW) system has been studied by X-ray powder diffraction and transmission electron microscopy. LMT and BMW were found to form solid solutions in the whole compositional range. Increase of BMW content results in two structural transformations: continuous P2(1)/n --> I2/m at x between 0.2 and 0.25 and discontinuous I2/m --> Fm(3) over barm at x between 0.4 and 0.5. This sequence of the phase transitions is compared with structural transformations in other solid solutions between dielectric complex perovskites. It is supposed that the discontinuity of the I2/m --> Fm(3) over barm phase transition might contribute to some peculiarities in the compositional dependence of dielectric characteristics of this system. (C) 2005 Elsevier Ltd. All rights reserved.
Photochemical Mineralization of Europium, Titanium, and Iron Oxyhydroxide Nanoparticles in the Ferritin Protein Cage
作者:Michael T. Klem、Jesse Mosolf、Mark Young、Trevor Douglas
DOI:10.1021/ic701740q
日期:2008.4.1
The Fe storage protein ferritin was used as a size-constrained reaction vessel for the photoreduction and reoxidation of complexed Eu, Fe, and Ti precursors for the formation of oxyhydroxide nanoparticles. The resultant materials were characterized by dynamic light scattering, gel electrophoresis, UV-vis spectroscopy, and transmission electron microscopy. The photoreduction and reoxidation process is inspired by biological sequestration mechanisms observed in some marine siderophore systems.
Photoluminescence in disordered Zn2TiO4
作者:Alexsandra C. Chaves、Severino J.G. Lima、Regiane C.M.U. Araújo、Maria Aldeiza M.A. Maurera、Elson Longo、Paulo S. Pizani、Luiz G.P. Simões、Luiz E.B. Soledade、Antonio G. Souza、Ieda Maria Garcia dos Santos
DOI:10.1016/j.jssc.2005.12.018
日期:2006.4
In this work, the polymeric precursor method Was used to obtain disordered Zn2TiO4 powders, either Undoped or doped with Sn4+, Cr3+ and V5+, to be applied its photoluininescent material. The characterization was undertaken by means of thermal analysis (TG and DTA), X-ray diffraction (XRD), infrared spectroscopy (IR) and photoluminescence (PL). Previous works stated that titanate octahedra containing a short Ti-O distance show efficient luminescence at roorn temperature if these octahedra are isolated from each other. In the present work, the phenomenon was observed in condensed octahedra, sharing edges. The room temperature PL noticed in undoped Zn2TiO4 had its intensity increased by the dopant addition-the increase was of about 300% for V5+ doping 400% for Cr3+ and 800% for Sn4+. (c) 2005 Elsevier Inc. All rights reserved.