Temperature-induced surface reconstruction and interface structure evolution on ligament of nanoporous copper

Wenbo Liu,Sanqiang Shi,Shichao Zhang,Peng Cheng,Ning Li,Jiazhen Yan

doi:10.1038/s41598-017-18795-9

Wenbo Liu, Sanqiang Shi + Show 4 more

Open Access

https://doi.org/10.1038/s41598-017-18795-9

Copy DOI

Abstract

Micromorphology and atomic arrangement on ligament surface of nanoporous metals play a vital role in maintaining the structural stability, adjusting the reaction interface and endowing the functionality. Here we offer an instructive scientific understanding for temperature-induced surface reconstruction and interface structure evolution on ligament of nanoporous copper (NPC) based on systematically experimental observations and theoretical calculations. The results show that with dealloying temperature increasing, ligament surface micromorphology of NPC evolves from smooth to irregularity and to uniformly compressed semisphere, and finally to dispersed single-crystal nanoparticles accompanying with significant changes of interface structure from coherence to semi-coherence and to noncoherence. It can guide us to impart multifunctionality and enhanced reaction activity to porous materials just through surface self-modification of homogeneous atoms rather than external invasion of heteroatoms that may bring about unexpected ill effects, such as shortened operation life owing to poisoning.

Highlights

Nowadays, nanoporous metals (NPMs) have attracted a lot of interest in a broad variety of applications involving actuators, catalysts, heat exchangers, microfluidic flow controllers, and so on[1,2,3,4,5,6,7,8]
A smooth and straight ligament surface without obvious surface embossment can be clearly observed in the nanoporous copper (NPC) dealloyed at RT
The superfine nanoparticles with a size of ~5 nm can be found on the ligament surface of NPC as the dealloying temperature climbs upto 363 K

Summary

Introduction

Nanoporous metals (NPMs) have attracted a lot of interest in a broad variety of applications involving actuators, catalysts, heat exchangers, microfluidic flow controllers, and so on[1,2,3,4,5,6,7,8]. Co3O4-embellished NPMs dramatically raised the detection sensitivity and accuracy as microelectrodes for electrochemical nonenzymatic glucose biosensors[28]. All these are closely related to unique porous architecture facilitating accommodation of volume change, increase of active site as well as fast infiltration of electrolyte and involved diffusion species. Studies on this issue have been made so far, which is considerably beneficial for profoundly understanding the intrinsic nature and unique characteristics (nanoporosity, interface activity and atom occupancy) of NPMs, but is a great challenge to us. The surface diffusivity and diffusion activation energy are evaluated to reveal the intrinsic nature of formation of nanoporous structure, including initial pore size, critical characteristic length, shortest formation time, etc. Based upon our deep understanding of dealloying physical nature, evolution mechanism is discussed in detail

Methods

Results

Conclusion