Large scale synthesis of flower-like SnO2 nanostructures via a facile hydrothermal route

doi:10.1016/j.matlet.2013.09.081

Materials Letters

Volume 113, 15 December 2013, Pages 42-45

https://doi.org/10.1016/j.matlet.2013.09.081 Get rights and content

Highlights

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The synthesized SnO₂ sample presents unique flower-like hierarchical architectures which were much less reported.
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The role of additives on the morphology of the products was investigated in detail.
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A novel growth mechanism is proposed based on comparative studies.

Abstract

Materials with hierarchical architectures often exhibit novel functional properties. In this paper, the hierarchical SnO₂ flower-like architecture, consisting of numerous aggregative nanosheets was successfully synthesized via a facile hydrothermal method and subsequent calcination. The structures and morphologies of this hierarchical architecture were characterized in detail by means of powder X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM). Further comparative experiments show that the sodium citrate was benefit to promote the growth of SnO₂ nanosheets and accelerate the assembling of nanosheets into flower-like architecture, the PEG provided nucleation sites and made the nanoflowers grow uniformly and separated. Moreover, a possible growth mechanism of the flower-like architectures was proposed. The non-trivial behavior of flower-like SnO₂ may be driven by the properties of grain boundaries.

Graphical abstract

We successfully synthesized hierarchical assembled flower-like SnO₂ with the reagents of sodium citrate and PEG via a simple hydrothermal technique and subsequent calcination.

Introduction

Tin oxide (SnO₂), as a multifunctional n-type semiconductor with a wide band gap (E_g=3.6 eV), has been the eye-catching in various fields, such as catalysts [1], gas sensors [2], solar cell [3], optoelectronic devices [4], and electrode materials [5]. Over the past years, the controlled synthesis of complex nanomaterials with unusual architectures has attracted vast interests due to their unique structures as well as their tremendous potential application in various fields [6]. Particularly, the novel three-dimensional (3D) hierarchical architectures which are assembled of 1D or 2D nanoscale building blocks. Various methods, such as thermal evaporation technique [7], sol-gel method [8], chemical vapor deposition (CVD) [9] and hydrothermal route [10] have been developed to fabricate 3D hierarchical architectures. Among them, the hydrothermal method has been proved to be effective for preparation hierarchical SnO₂ architectures [11]. Zhang et al. fabricated flower-like nanospheres via one step template-free hydrothermal reaction with the help of PEG400 [12]; Huang et al. prepared pours flower-like SnO₂ nanostructure with average size of 6.1 nm by annealing of the flower-like tin sulfur (SnS₂) nanostructures [13]. Although the above various morphologies of SnO₂ have been synthesized, it still remains a huge challenge to self-assemble nanostructures with well-defined morphology and uniform size.

In our present work, the hierarchical flower-like SnO₂ architecture consisting of nanosheets was successfully synthesized via sodium citrate and PEG assisted hydrothermal. The as-prepared products were illuminated in terms of their crystallinity, morphology and structure. Furthermore, the functions of reagents on the morphologies of precursors were investigated in detail. A possible growth mechanism was elaborated. The non-trivial behavior of nanosized SnO₂ may be driven by the properties of grain boundaries.

Section snippets

Experimental

All the chemicals were analytical-grade reagents and were directly used without further purification. In a topical hydrothermal process, Tin(II) chloride dihydrate (SnCl₂ radical dot 2H₂O, 4 mmol), sodium citrate (Na₃C₆H₅O₇2H₂O, 10 mmol), Sodium hydroxide (NaOH, 2 mmol) and polyethylene glycol (PEG, 2 mmol) were dissolved into 10 ml distilled water with vigorous stirring. Later, 10 ml ethanol was added and a milky-white solution was obtained, which was next transferred into a Teflon-lined stainless steel

Results and discussion

The phase and purity of the products were identified by X-ray powder diffraction (XRD) measurement. The typical XRD patterns of the final SnO₂ product were presented in Fig. 1(a), all of the diffraction peaks can be well indexed to the tetragonal rutile SnO₂ structure (JCPDS No. 41-1445, a_o=b_o=4.738 Å, and c_o=3.187 Å). No characteristic peaks were observed for other impurities, revealing the high purity of the prepared SnO₂. The strong and sharp peaks indicate that the products are highly

Conclusions

In summary, 3D hierarchical flower-like SnO₂ architectures consisting of well ordered nanosheets were synthesized via the hydrothermal route and thermal annealing processes. The role of additives on the morphology of the products was investigated in detail. We found that sodium promotes the formation of nanosheets and assembles the nanosheets in flower-like architecture and that PEG provides nucleation sites and makes the nanoflowers grow more uniformly. Furthermore, a possible growth mechanism

Acknowledgments

This work was supported in part by National Natural Science of China (51202302), Fundamental Research Funds for the Central Universities (No. CDJZR12130051) and China Postdoctoral Science Foundation funded project (No. 2013T60839).

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Large scale synthesis of flower-like SnO2 nanostructures via a facile hydrothermal route

Highlights

Abstract

Graphical abstract

Introduction

Section snippets

Experimental

Results and discussion

Conclusions

Acknowledgments

Applied Catalysis B

Physica E

Materials Letters

Materials Letters

Materials Letters

Sensors and Actuators B

Physica E

Chemistry of Materials

Large scale synthesis of flower-like SnO₂ nanostructures via a facile hydrothermal route