Atomic Layer Electrodeposition of Pt on Nanoporous Au and its Application in pH Sensing

The preparation of nanoporous metal structures has received a substantial amount of attention because of the unique properties and various applications of these structures. In this work, the preparation of nanoporous Pt structures by modification of nanoporous gold (NPG) surfaces with Pt was achieved. An atomic layer electrodeposition (ALED) technique previously reported for the modification of flat Au surfaces with Pt was applied to the NPG surfaces to produce Pt-modified NPG structures. The optimal ALED parameters, such as deposition potential, time, and number of cycles, for the preparation of Pt-modified NPG structures were investigated. Scanning electron microscopy and energy-dispersive X-ray analysis confirmed the successful preparation of nanoporous Pt structures by ALED techniques. The Pt-modified NPG performed well as a pH sensor with a Nernstian slope and negligible hysteresis. The method of preparing the nanoporous Pt structures reported in this work could be utilized in various applications such as electrocatalysis and electroanalysis.