Size Controlled Synthesis of Tellurium Nanorices by Galvanic Displacement Reaction of Aluminum

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• 作者：Tingjun Wu^a ; Lawrence Youngjae Myung^b ; Miluo Zhang^a ; Kyu-Hwan Lee^c ; Yeheun Laura Lee^d ; Hyo-Ryong Lim^e ; Bum Sung Kim^f ; Yong-Ho Choa^e ; Nosang V. Myung^a ; ^{myung@engr.ucr.edu" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Tellurium ; nanorice ; galvanic displacement reaction ; alkaline bath ; aluminum
• 刊名：Electrochimica Acta
• 出版年：2015
• 出版时间：10 September 2015
• 年：2015
• 卷：176
• 期：Complete
• 页码：1382-1392
• 全文大小：2963 K

文摘

Tellurium nanostructures were synthesized by galvanic displacement reaction (GDR) of aluminum in an alkaline solution containing TeO₃²⁻ ions. Due to negative redox potential of Al/AlO₂⁻ (i.e., −2.50 V vs. sat. Ag/AgCl), TeO₃²⁻ (+IV) can be reduced to Te₂²⁻ (-I) and Te²⁻ (-II), which resulted in the deposition of Te (0) nanostructures in the solution via chemical reaction between Te₂²⁻ or Te²⁻ and TeO₃²⁻. The deposition mechanism led to the formation of unique “rice-like” nanostructures in the solution instead of branched structures on the substrate. The sharp tips of the “rice-like” nanostructures may be attributed to the high density of surface charges at the tips. The morphology, diameter and aspect ratio of Te “rice-like” nanostructures were altered by the TeO₃²⁻ concentration, solution pH, reaction time and the reaction temperature. Electrochemical analytical methods, including open circuit potential (OCP) and linear polarizations (LPs), were used to investigate the reaction mechanisms. The enhancement of piezoelectric constant (d₁₁) of nanorices at small diameter was probably due to a flexoelectric effect.