Electrochemical growth mechanism of nanoporous platinum layers

Abstract

Porous platinum is a frequently used catalyst material in electrosynthesis and a robust broadband absorber in thermoelectrics. Pore size distribution and localization determine its properties by a large extent. However, the pore formation mechanism during the growth of the material remains unclear. In this work we elucidate the mechanism underlying electrochemical growth of nanoporous platinum layers and its control by ionic concentration and current density during electrolysis. The electrode kinetics and reduction steps of PtCl4 on platinum electrodes are investigated by cyclic voltammetry and impedance measurements. Cyclic voltammograms show three reduction steps: two steps relate to the platinum cation reduction, and one step relates to the hydrogen reduction. Hydrogen is not involved in the reduction of PtCl4, however it enables the formation of nanopores in the layers. These findings contribute to the understanding of electrochemical growth of nanoporous platinum layers in isopropanol with thickness of 100 nm to 500 nm.

Nanoporous Platinum Microelectrode Arrays for Neuroscience Applications

“…As shown in both this and previous studies, the electrodeposition of nanoporous platinum is a versatile process that can be fine-tuned to create a variety of nano-and microstructures (33,37). Numerous parameters influence the characteristics of the formed deposits, including the choice of additives, working electrode material, temperature of the elec-trochemical bath, deposition current/voltage, and deposition time (16,17,38).…”

Porous Noble Metal‐Based Nanomaterials in Biomedical Applications

“…[52] Consequently, preparing porous noble metal-based nanomaterials with desiderated structure and design is still challenging, and other methods, such as electrochemical growth, are being developed. [40] Furthermore, the inherent instability of surface atoms leads to higher surface free energy and reduced thermodynamic stability. [57,58] Such factors render porous nanomaterials susceptible to phase separation and aggregation.…”

“…Several preparation strategies have been used including template‐based method, [ 38 ] dealloying technique, [ 39 ] and electrochemical growth method. [ 40 ]…”

“…[ 22 ] In response, researchers are exploring alternative approaches, including ongoing advancements in electrochemical growth methods. [ 40 ] Stanca et al investigated the mechanism of nanoporous platinum in two steps: hydrogen reduction and platinic chloride reduction. [ 40 ] Platinum microelectrodes formed hydrogen bubbles on the surface due to hydrogen reduction.…”

“…[ 40 ] Stanca et al investigated the mechanism of nanoporous platinum in two steps: hydrogen reduction and platinic chloride reduction. [ 40 ] Platinum microelectrodes formed hydrogen bubbles on the surface due to hydrogen reduction. Subsequently, the platinum was deposited on the electrode, forming a porous structure due to hydrogen bubbles.…”