General synthesis of complex nanotubes by gradient electrospinning and controlled pyrolysis.

Chaojiang Niu,Dongyuan Zhao,Lin Xu,Qingjie Zhang,Kangning Zhao,Xuanpeng Wang,Liqiang Mai,Wenhao Ren,Jiashen Meng,Xiaoming Xu,Chunhua Han,Mengyu Yan,Yunlong Zhao

doi:10.1038/ncomms8402

Chaojiang Niu, Dongyuan Zhao + Show 11 more

Open Access

https://doi.org/10.1038/ncomms8402

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Abstract

Nanowires and nanotubes have been the focus of considerable efforts in energy storage and solar energy conversion because of their unique properties. However, owing to the limitations of synthetic methods, most inorganic nanotubes, especially for multi-element oxides and binary-metal oxides, have been rarely fabricated. Here we design a gradient electrospinning and controlled pyrolysis method to synthesize various controllable 1D nanostructures, including mesoporous nanotubes, pea-like nanotubes and continuous nanowires. The key point of this method is the gradient distribution of low-/middle-/high-molecular-weight poly(vinyl alcohol) during the electrospinning process. This simple technique is extended to various inorganic multi-element oxides, binary-metal oxides and single-metal oxides. Among them, Li3V2(PO4)3, Na0.7Fe0.7Mn0.3O2 and Co3O4 mesoporous nanotubes exhibit ultrastable electrochemical performance when used in lithium-ion batteries, sodium-ion batteries and supercapacitors, respectively. We believe that a wide range of new materials available from our composition gradient electrospinning and pyrolysis methodology may lead to further developments in research on 1D systems.

Highlights

Nanowires and nanotubes have been the focus of considerable efforts in energy storage and solar energy conversion because of their unique properties
We design a universal gradient electrospinning followed by controlled pyrolysis methodology to synthesize various types of mesoporous nanotubes and pea-like nanotubes (Fig. 1), including multi-element oxides, binary-metal oxides and singlemetal oxides
The viscous homogeneous precursor solution was prepared by mixing low, middle- and high-molecular-weight poly(vinyl alcohol) (PVA) and different needed inorganic materials

Summary

Introduction

Nanowires and nanotubes have been the focus of considerable efforts in energy storage and solar energy conversion because of their unique properties. Electrospinning techniques have been studied for the fabrication of conductive polymer nanowires and a part of inorganic material nanowires[19,20,21] This method along with different post-treatments has been applied to synthesize some interesting surface multilevel structures (branched nanowires and necklacelike nanowires) and inner multilevel structures (core/shell nanowires and multichannel microtubes)[22,23,24,25,26]. We design a universal gradient electrospinning followed by controlled pyrolysis methodology to synthesize various types of mesoporous nanotubes and pea-like nanotubes (Fig. 1), including multi-element oxides, binary-metal oxides and singlemetal oxides. This strategy is achieved through electrospinning with one ordinary syringe needle while modulating low-, middleand high-molecular-weight poly(vinyl alcohol) (PVA) in the precursor. Li3V2(PO4)[3], Na0.7Fe0.7Mn0.3O2 and Co3O4 mesoporous nanotubes were selected as electroactive materials in lithium-ion batteries, sodium-ion batteries and supercapacitors, respectively

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