کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1653389 1517344 2006 4 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Simultaneous synthesis of high crystalline manganese oxides with layered and tunnel structures
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد فناوری نانو (نانو تکنولوژی)
پیش نمایش صفحه اول مقاله
Simultaneous synthesis of high crystalline manganese oxides with layered and tunnel structures
چکیده انگلیسی

High crystalline manganese oxides with birnessite-type (H-BirMO) and large 2 × 4 tunnel-type (Na-2 × 4) were synthesized simultaneously using a low crystalline Na-form birnessite (NaBir) as a precursor in a 2 M NaOH solution at low temperature (150 °C) and autogenous pressure. The weight ratio of the obtained Na-2 × 4 to H-BirMO was about 50. Elemental analyses indicated that Na-2 × 4 had a formula in one unit cell of Na8Mn27O53·9H2O, and the manganese average oxidation state was 3.63. H-BirMO had a formula of Na0.31Mn2.04O4·0.66H2O and the manganese average oxidation state of 3.77. H-BirMO contained a set of basal reflections with d values that correspond to a minimum periodicity along c equal to 7.06 Å. H-BirMO belonged to a monoclinic system, and the lattice parameters were a = 5.18 Å, b = 2.85 Å, c = 7.35 Å, and β = 103.3°, respectively. Na-2 × 4 showed that the first peak appeared at a d spacing of 12.07 Å in the [0 0 2] direction, and the second peak had a similar d spacing of 7.16 Å in the [2 0 0] direction with Na-birnessite in the [1 0 0] direction. FE-SEM image of H-BirMO showed a very large plate-like morphology, while SEM photograph of Na-2 × 4 consisted of nanofibers with a thickness of about 80 nm and lengths ranging between 6 and 10 μm.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Letters - Volume 60, Issues 29–30, December 2006, Pages 3565–3568
نویسندگان
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