کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1489573 992309 2011 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Preparation with a facile template-free method of uniform-sized mesoporous microspheres of rare earth (La, Ce, Pr, Nd) oxides
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Preparation with a facile template-free method of uniform-sized mesoporous microspheres of rare earth (La, Ce, Pr, Nd) oxides
چکیده انگلیسی

Mesoporous microspheres of light rare earth (La, Ce, Pr, Nd) hydroxycarbonates and oxides were successfully fabricated by a facile surfactant free hydrothermal method in supersaturated aqueous urea solution. The techniques of XRD, TEM, SEM, TG/DTA and N2 adsorption–desorption were employed to investigate the structure and formation process of mesoporous microspheres. It was revealed that supersaturated urea not only serve as a reactant and pH modifier in the reaction system but also guide the oriented assembly of hydroxycarbonate crystallites into microspheres by acting as a structure-directing agent. The microspheres of rare earth oxides could easily be obtained by simple calcination of corresponding hydroxycarbonates precursors without undergoing morphology changes. In addition, the influences of rare earth precursor and urea concentrations on the formation of microspheres were also investigated.

Figure optionsDownload as PowerPoint slideHighlights
► Mesoporous microspheres of light rare earth hydroxycarbonates and oxides were fabricated.
► The supersaturated urea has important effect on formation of mesoporous microspheres.
► The influences of [cation]/[urea] ratio and amount of water on the formation of spherical crystallites were discussed.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Research Bulletin - Volume 46, Issue 11, November 2011, Pages 1902–1907
نویسندگان
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