Directional hierarchical porous Cu prepared by one-step etching 3D printed Fe-Cu alloy with two-stage phase separation structure

摘要

Directional hierarchical porous metals have attracted a lot of attention due to their enhanced performance in catalysis, sensing and surface modifications. But the preparation of directional hierarchical porous metals is usually complex and expensive. In the present work, a directional hierarchical porous Cu has been prepared by one-step etching of a 3D printed Fe-Cu alloy with two-stage phase separation structure without template. The morphology evolution of the directional hierarchical porous Cu was investigated. During the 3D printing process, the Fe-Cu melt firstly separates into a Cu-rich network and a Fe-rich dot-like phase that grows along the heat flow direction. Then the Fe-rich dot-like phase further separates into a Cu-rich phase and a Fe-rich phase in nanoscale. After etching the Fe-rich phase off, directional hierarchical porous Cu forms. The structure as well as the wettability of the directional hierarchical porous Cu can be tuned by adjusting the etching time. This work proposes a new combined technique of one-step etching and 3D printing for the preparation of directional hierarchical porous metals.