Tuning the morphology of tellurium nanostructures by template-free electrodeposition in ionic liquids : from hollow nanostructures to hair-like nanowires - Université de Lorraine
Communication Dans Un Congrès Année : 2017

Tuning the morphology of tellurium nanostructures by template-free electrodeposition in ionic liquids : from hollow nanostructures to hair-like nanowires

Sophie Legeai
Jaafar Ghanbaja
Nicolas Stein

Résumé

Electrodeposition of nanowires is usually performed in a porous template and involves multiples fabrication steps, like the preparation of the template and its removal. A single step template-free electrodeposition would in some cases be more convenient, for example to synthesize core@shell structures. It has been shown in literature that ionic liquids, in addition to have high electrochemical and thermal stabilities, can act as capping agents allowing the formation of nanostructures without using a template [1]. We will present here the template-free electrodeposition of Te nanostructures in a piperidinium ionic liquid. A systematic study of the influence of synthesis parameters revealed that the deposits morphology mainly depends on mass transport conditions and Te(IV) speciation. Under diffusional control, nanowires are deposited (Figure a), whereas by applying high overpotential values and then severe mass transport conditions, hollow nanostructures are formed due to a limitation by species supply (Figure b) [2]. The electrolyte composition determines the Te(IV) speciation that also strongly influences the morphology of the nanostructures. Specifically, the addition of a small amount of bromide ions in the electrolyte allows to synthesize 70 µm long hair-like nanowires with a mean diameter of 50 nm (Figure c) [3]. High Resolution Transmission Electron Microscopy analyses show that the nanostructures are single crystalline and grow along the c-axis, with a smooth interface and no external surface layer (Figure d). Examples of core@shell nanostructures that could present interesting properties in the field of thermoelectrics will also be presented, elaborated by electrodeposition of a shell on the Te nanowires.

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Dates et versions

hal-01494624 , version 1 (23-03-2017)

Identifiants

  • HAL Id : hal-01494624 , version 1

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Sophie Legeai, Laura Thiebaud, Jaafar Ghanbaja, Nicolas Stein. Tuning the morphology of tellurium nanostructures by template-free electrodeposition in ionic liquids : from hollow nanostructures to hair-like nanowires. EDNANO12, Mar 2017, Sofia, Bulgaria. ⟨hal-01494624⟩
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