Electrochemical Deposition of Nanostructured (H₁-e) Layers of Two Metals in Which Pores within the Two Layers Interconnect

Abstract

Electrochemical deposition of metals from the H 1 hexagonal phase of nonionic lyotropic liquid-crystalline phases has been shown to produce films which contain regular arrays of uniform pores whose dimensions are determined by those of the micelles in the lyotropic phase used as the template. In this paper we report results for a study of the deposition of one H 1 -e metal film on top of another. Using H 1 -e films of palladium and rhodium as a model system we show, using electrochemical measurements, that the surface of the pores of the inner metal film are not blocked by deposition of an overlayer of the second mesoporous metal. By studying the evolution of the voltammetry of the mesoporous metallic bilayers as the surfactant is leached out of the pores over time, we conclude that the pores in the outer H 1 -e metal film connect to those in the inner layer so that we have a hexagonal array of continuous pores running though both metal layers in the structure.

Lyotropic liquid crystal directed synthesis of nanostructured materials

“…It is proved that electrodeposition of metals from the H 1 hexagonal phase of nonionic LLC phases can produce films containing regular arrays of uniform pores whose dimensions are determined by those of the micelles in the LLC phase. Bartlett and Simon extended this idea and demonstrated that they could electrochemically deposit the mesoporous films of two metals, one on top of the other, by which they produced a single nanostructure with the pores running continuously through the two metal layers [64]. Figure 2 is the schematic representation of the templating process.…”

Beyond Silica: Nonoxidic Mesostructured Materials

“…This direct templated synthesis creates a novel route to mesoporous metals. [75] Since the first report of mesoporous Pt particles, several mesoporous metals (e.g., Pt, [76] Sn, [77] Co, [78] Pd, [79,80] Te, [81] Ni, [82] and Rh [83] ) have been prepared by chemical or electrochemical reduction of the corresponding metal salts dissolved in aqueous domains of the liquid-crystal template. The formation of mesoporous Ni particles and Pt thin films by autocatalytic deposition and a contact-plating method respectively have also been described.…”

Apparent electrocatalysis on 3D nanoporous platinum film electroplated from hexagonal lyotropic liquid crystalline phase of Triton X-100

“…1) and water, could produce a nanoporous Pt film with cylindrical pores of hexagonal array (2.5 nm of pore diameter and 5.0 nm of pore-pore distance), namely, H 1 -ePt [11]. Other metals (e.g., Sn [6], Rh [14], Pd [14], Ni [15], Pt-Pd [16], Pd-Pt [16], Pt-Ru [17], and Cd [18]) were also electrodeposited to be 2D-hexagonal nanoporous structures, which were a direct cast of H 1 -LLC. These nanoporous metal films were electroplated in LLC based on polyoxyethylene alkyl ether with an aliphatic nonpolar group.…”