Lattice defects and oxide formation coupledly enhanced giant electrical resistance change in nanoporous silver

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• 作者：Qingguo Bai ; Jie Zhang ; Conghui Si ; Zhen Qi ; Zhonghua Zhang ; ^{zh_zhang@sdu.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：nanoporous silver ; electrical resistance ; silver oxide ; lattice defects ; dealloying
• 刊名：Electrochimica Acta
• 出版年：2016
• 出版时间：10 July 2016
• 年：2016
• 卷：206
• 期：Complete
• 页码：26-35
• 全文大小：3258 K

文摘

The electrochemically induced electrical resistance response of nanostructured metallic materials is an important issue in interdisciplinary fields including electrochemistry, physics and surface science. Nanoporous metals possess an open three-dimensional bicontinuous ligament (nanowire network)-channel (nanopore) structure with high surface-to-volume ratios, and show great potentials for investigations in this topic. Here we fabricate nanoporous silver (NPS) with high density of lattice defects (dislocations, twins, stacking defaults and grain boundaries) and ligaments composed of Ag nanocrystals with sizes comparable to the ligament length scale. More importantly, the present NPS shows extraordinarily enhanced reversible resistance response to electrochemical stimuli in alkaline electrolytes. A giant reversible resistance change of up to ∼1100% has been achieved in NPS. Moreover, the reversible electrical resistance change of NPS can be well modulated through cyclic voltammetry or square wave potential input. The related mechanisms have been rationalized on the basis of reversible oxide formation/reduction on the ligament surface of NPS, silver dissolution, as well as the effects of lattice defects in NPS.