A Feasible Strategy for Fabricating Surface Porous Network in Fe-Si Ribbons.

Porous materials have always attracted extensive attention owing to their low density, tunable porosity and high surface area. Generally, porosity is introduced in amorphous materials through dealloying or electrochemical dealloying processes. In this work, an iron-based surface porous network was successfully fabricated utilizing selective electrochemical dissolution of Fe-Si alloy ribbons based on the cellular structure prepared by melt-spinning technique. After 30 s, the surface of the ribbon gradually becomes flat and grains can be observed in the first stage of electrochemistry; after an extra 10 s, the pores spread throughout the surface of the ribbon in the second stage. The average size of pores is about 310 nm and the average size of the ligament is 150 nm. The associated dissolution mechanism has been proposed based on the inhomogeneous composition of the center and edge of the cell. The entire process of electrochemical dissolution has been divided into two stages and the entire duration of synthesis does not exceed one minute. This method is extremely feasible and provides a promising strategy for preparing surface porous materials for selective electrochemical dissolution of cellular structure.