Lattice defects and oxide formation coupledly enhanced giant electrical resistance change in nanoporous silver. (10th July 2016)

• Record Type: Journal Article
• Authors: Bai, Qingguo; Zhang, Jie; Si, Conghui; Qi, Zhen; Zhang, Zhonghua
• Is Part Of: Electrochimica acta. Volume 206(2016)
• Page Start: 26
• Page End: 35
• Publication Date: 2016-07-10
• Subjects: nanoporous silver -- electrical resistance -- silver oxide -- lattice defects -- dealloying; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2016.04.091
• Languages: English
• ISSNs: 0013-4686

Abstract

Graphical abstract: Nanoporous silver (NPS) fabricated by dealloying possesses large density of lattice defects (dislocations, twins, stacking defaults and grain boundaries) and ligaments composed of silver nanocrystals with sizes comparable to the ligament length scale. A giant reversible resistance of up to ∼1100% has been achieved for electrochemically induced response in NPS, which could be attributed to both the surface adsorption of chemical species and the aid of lattice defects. Abstract: 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.