Fabrication of Nanoporous Pt by Electrochemical Alloying and Dealloying with Li

Abstract

There has been considerable interest in the fabrication of porous metals with nanometer dimensions owing to their capability for application in various devices such as functional electrodes, 1 catalysts 2 and sensors. 3 For the formation of nanoporous metals, various template 4,5 or dealloying 6,7 processes are generally adopted. Among them, dealloying,inwhichanelectrochemicallycathodicmetalisselectivelydissolved from an alloy, is widely adopted owing to its facility in forming nanoporous metals with desired geometrical structures. However, this process has some drawbacks in that, prior to dealloying, alloys with a homogeneous composition have to be prepared. In addition, the contamination by the residual metal is a problem to be solved. Recently, we have developed a new process for the formation of nanoporous metals without the necessity of preparing such alloys based on the electrochemical alloying and dealloying of a metal with Li. 8 In this process, electrochemical alloying followed by electrochemical dealloyingwithLiinanonaqueouselectrolyteatroomtemperatureenables the formation of nanoporous Au. This process can be applied to the easy formation of nanoporous structures of a wide variety of metals. In the present report, we describe the application of this process to the formation of nanoporous Pt to confirm its versatility for the formation of various nanoporous metals in addition to Au although the relevant process using PtO has been reported. 9 Nanoporous Pt is a typical material used for functional electrodes, and the development of an effective preparation process for nanoporous Pt will be useful in various electrochemical application fields.