Highly Crystalline Inverse Opal Transition Metal Oxides via a Combined Assembly of Soft and Hard Chemistries

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• 作者：M. Christopher Orilall ; Neal M. Abrams ; Jinwoo Lee ; Francis J. DiSalvo ; Ulrich Wiesner
• 刊名：Journal of the American Chemical Society
• 出版年：2008
• 出版时间：July 16, 2008
• 年：2008
• 卷：130
• 期：28
• 页码：8882 - 8883
• 全文大小：523K
• 年卷期：v.130,no.28(July 16, 2008)
• ISSN：1520-5126

文摘

A combined assembly of soft and hard chemistries is employed to generate highly crystalline three-dimensionally ordered macroporous (3DOM) niobia (Nb₂O₅) and titania (TiO₂) structures by colloidal crystal templating. Polystyrene spheres with sp² hybridized carbon are used in a reverse-template infiltration technique based on the aqueous liquid phase deposition of the metal oxide in the interstitial spaces of a colloidal assembly. Heating under inert atmosphere as high as 900 °C converts the polymer into sturdy carbon that acts as a scaffold and keeps the macropores open while the oxides crystallize. Using X-ray diffraction it is demonstrated that for both oxides this approach leads to highly crystalline materials while heat treatments to lower temperatures commonly used for polymer colloidal templating, in particular for niobia, results in only weakly crystallized materials. Furthermore it is demonstrated that heat treatment directly to higher temperatures without generating the carbon scaffold leads to a collapse of the macrostructure. The approach should in principle be applicable to other 3DOM materials that require heat treatments to higher temperatures.