Mechanistic Insights into Formation of SnO2 Nanotubes: Asynchronous Decomposition of Poly(vinylpyrrolidone) in Electrospun Fibers during Calcining Process

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• 作者：Jinjin Wu ; Dawen Zeng ; Xiaoxia Wang ; Lei Zeng ; Qingwu Huang ; Gen Tang ; Changsheng Xie
• 刊名：Langmuir
• 出版年：2014
• 出版时间：September 23, 2014
• 年：2014
• 卷：30
• 期：37
• 页码：11183-11189
• 全文大小：575K
• ISSN：1520-5827

文摘

The formation mechanism of SnO₂ nanotubes (NTs) fabricated by generic electrospinning and calcining was revealed by systematically investigating the structural evolution of calcined fibers, product composition, and released volatile byproducts. The structural evolution of the fibers proceeded sequentially from dense fiber to wire-in-tube to nanotube. This remarkable structural evolution indicated a disparate thermal decomposition of poly(vinylpyrrolidone) (PVP) in the interior and the surface of the fibers. PVP on the surface of the outer fibers decomposed completely at a lower temperature (<340 掳C), due to exposure to oxygen, and SnO₂ crystallized and formed a shell on the fiber. Interior PVP of the fiber was prone to loss of side substituents due to the oxygen-deficient decomposition, leaving only the carbon main chain. The rest of the Sn crystallized when the pores formed resulting from the aggregation of SnO₂ nanocrystals in the shell. The residual carbon chain did not decompose completely at temperatures less than 550 掳C. We proposed a PVP-assisted Ostwald ripening mechanism for the formation of SnO₂ NTs. This work directs the fabrication of diverse nanostructure metal oxide by generic electrospinning method.