Self-Healing of Nanoporous Gold Under Ambient Conditions

Abstract

Failure of a material is an irreversible process since the material loses its original characteristics and properties. The catastrophic brittle failure under tensile stress of nanoporous gold (np-Au) with a bicontinuous open-cell structure makes impossible otherwise attractive applications. Here, we first demonstrate a self-healing process in tensile-fractured np-Au to overcome the limit of fragility via mechanically assisted cold-welding under ambient conditions. The self-healing ability of np-Au in terms of mechanical properties shows strength recovery up to 64.4% and fully recovered elastic modulus compared with initial tensile properties. Topological parameters obtained by three-dimensional reconstruction of self-healed np-Au clarify the strength, elastic modulus, and strain distribution. The self-healing process in np-Au is attributed to surface diffusion expedited by local compressive stress in the ultrasmall dimension of ligaments formed by ductile failures of individual ligaments.

Accelerated Electron Transfer in Nanostructured Electrodes Improves the Sensitivity of Electrochemical Biosensors

“…We fabricated the nanoporous electrodes using a dealloying process with Ag:Au alloys. [38,39] The pore size in these electrodes can be tuned by adjusting the ratio of Ag to Au. We used two approaches-thermal annealing [28] and electrochemical coarsening 29 -to adjust the average pore and ligament sizes in our nanoporous structures.…”

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“…Figure 4e shows a TEM image of the assembled AuAg NSs. The NS lattice fringes of the (200) and (111) planes are 0.20 and 0.24 nm, respectively, which can be determined based on the HRTEM analysis in Figure 4f.…”

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Structural evolution and mechanical stabilities of head-to-side nanowelding of Cu–Ag bimetallic nanowires via atomistic simulations

“…Formation of an Ag nanowire network via the three ways was also discovered by Peng et al, 11 demonstrating nanowelding for a room temperature pressureless Cu a School of Intelligent Manufacturing and Control Engineering, Shandong Institute substrate and Ag nanowire paste at the same time. Threedimensional reconstruction of self-healed nanoporous Au by Gwak et al 12 further stressed the great importance of different contact modes in the recovery and bottom-up synthesis of nanomaterials.…”