Fabrication of Porous Metal Particles with Controlled Surface Structures by Barrel Anode Etching

Porous Al particles with etching pits on their surfaces were prepared by anode etching using a rotating barrel. In this process, Al particles were placed in a barrel with a Pt plate electrode at the bottom. The Al particles were electrified by contacting the Pt electrode in the rotating barrel, and anode etching occurred on the surfaces of the Al particles. The structure of the etching pits formed on the surfaces of the Al particles could be controlled by adjusting the current and electrolysis time during the barrel anode etching. In addition, using an electrolyte solution with a surfactant, it was possible to form etching pits even on the surfaces of Al particles with sizes of 5 μm or less. Porous Mg particles could also be prepared by barrel anode etching using fine Mg particles as the starting material. The porous metal particles obtained using this process have a wide range of potential applications, including sensors, catalyst carriers, and batteries.