Micelle‐Assisted Electrodeposition of Mesoporous Fe–Pt Smooth Thin Films and their Electrocatalytic Activity towards the Hydrogen Evolution Reaction

Abstract

Mesoporous Fe-Pt thin films are obtained by micelle-assisted electrodeposition onto metallic substrates with dissimilar activity (namely, gold, copper, and aluminum seed layers evaporated on Si/Ti) under constant applied potential (E=-1.1 V vs. Ag/AgCl) and deposition time (600 s). The amphiphilic triblock copolymer Pluronic P-123 is used as a soft template to guide the formation of mesopores. The occurrence of pores (ca. 7 nm in diameter) with narrow size distribution, distributed evenly over the surface, is observed in all cases. Despite the applied conditions being the same, the roughness and the amount of Fe incorporated in the films are influenced by the nature of the substrate. In particular, ultra-smooth films containing a larger amount of Fe (21 wt %) are obtained when deposition takes place on the Au surface. X-ray diffraction analyses reveal that Pt and Fe are alloyed to a certain extent, although some iron oxides/hydroxides also unavoidably form. The resulting films have been tested as electrocatalysts in the hydrogen evolution reaction (HER) in alkaline media. The mesoporous Fe-rich Fe-Pt films on Au show excellent HER activity and cyclability.

Electrodeposited Ni-Based Magnetic Mesoporous Films as Smart Surfaces for Atomic Layer Deposition: An “All-Chemical” Deposition Approach toward 3D Nanoengineered Composite Layers

“…In the case of the templated deposition of metals, their growth from the substrate is guided by the template and the mesoporous structure often emerges after the template is removed. Very recently, the usage of spherical micelles of di-or tri-block copolymers (e.g., polystyrene-blockpoly(oxyethylene) (PS-b-PEO) known as KLE or Poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEG-PPG-PEG) known as P-123) in water as soft-templates has been demonstrated for a number of metals (e.g., Au, Pt, Pd, Cu) [16][17][18][19] and alloys (Pt-Cu, Pt-Ru, Pt-Fe and Cu-Ni) [20][21][22][23][24] . Contrary to the evaporation-induced self-assembly approach, metal deposition and micelles assembly take place simultaneously in liquid phase without involving any solvent evaporation.…”

Functional macroporous iron-phosphorous films by electrodeposition on colloidal crystal templates

“…Remarkably, the traditional synthesis of transition metal phosphides often involves the release of the highly toxic phosphine, which is against of current precepts for green chemistry and sustainable management [45]. Moreover, the use of a polymer binder during electrode fabrication from catalyst powders is avoided here since the electrocatalyst material is directly attached to a conductive surface during electrodeposition [ [57], [58], [59]].…”

Microemulsion-Based One-Step Electrochemical Fabrication of Mesoporous Catalysts

“…However, it is not a generalizable option for any material, since in order to maintain the porogen capacity, the existence of an interaction between the precursors and the surfactants or the di-or tri-block copolymers micelles is necessary. This requirement is an important limitation that inhibits their potential usage, as certain precursors are extremely expensive [42,[59][60][61][62][63]. However, excellent and highly competitive electrocatalysts have been synthesized with this approach, such as mesoporous Pt nanorods with accessible and large effective surface areas of approximately 50 m 2 g −1 and excellent catalytic performance towards methanol electrooxidation [42] or mesoporous Fe-Pt thin films with enhanced electrocatalytic activity towards the hydrogen evolution reaction [63].…”