Three-Dimensional Nanoporous Metal Structures from Poly(2-vinylpyridine)-block-Poly(4-vinylpyridine) Copolymer Thin Film

Abstract

We fabricated 3D nanoporous metal structures from poly(2vinylpyridine)-block-poly(4-vinylpyridine) copolymer (P24VP) thin film with vertically oriented lamellar nanodomains by coordinating corresponding metal precursors followed by reduction to metals. Although metal precursors are coordinated with both P2VP and P4VP blocks, the metal coordination power toward P4VP block is much greater than that toward P2VP block. Thus, most of the metal precursors are located in the P4VP block, while a few exist in the P2VP block. After the metal precursors were reduced to corresponding metals by reactive ion etching, metals located in P4VP regions became continuous main frames. However, metals in P2VP regions could not be continuous because of smaller amounts, resulting in nanoporous structures. Using these 3D nanoporous structures, we measured the electrocatalytic activity for hydrogen evolution reaction. 3D nanoporous platinum (Pt) showed enhanced catalytic activity compared with Pt flat film due to the large surface area. Moreover, 3D nanoporous Pt/cobalt bimetallic structures showed better catalytic activity than 3D nanoporous Pt structures.

Block Copolymer Nanopatterning for Nonsemiconductor Device Applications

“…Bicontinuous 3D structures, such as gyroid and double-diamond (DD) structures, are promising materials for catalysts, because of their large specific surface area and uniform pore size throughout the film. , Moreover, the bicontinuous structure can contain large amounts of electrolytes and reactants that easily penetrate the inner space. , Furthermore, unlike other structures, these structures were stable without agglomeration. As the bicontinuous structure is difficult to induce through typical top-down methods, BCP self-assembly is the most suitable and facile method to obtain these structures.…”

Progress and perspective on polymer templating of multifunctional oxide nanostructures

“…form metallic nanolines of metals such as Pt, Au, and Pd. 146,147,[181][182][183] Only a few examples exist for the fabrication of simple oxides using CSD for horizontal morphologies, 184 sequential infiltration synthesis (Sec. III A) is more generally used in these cases for the fabrication of (simple) metal oxides.…”

Electrolysis on a Chip with Tunable Thin Film Nanostructured PGM Electrocatalysts Generated from Self‐Assembled Block Copolymer Templates

“…For example, Ross and co-workers [24,26] fabricated metallic nanowires of varying compositions (e.g., Ti, W, Pt, Co, and Au) from poly(styrene-block-dimethylsiloxane) (PSbPDMS) parallel cylinders via a combination of PVD and plasma treatment with O 2 and CF 4 . The second method involves incipient wetness impregnation (IWI) [6,8,[27][28][29][30][31][32][33][34] followed by reduction of metals and removal of the BCP template. [35,36] An example of IWI by Buriak and co-workers [8] selectively infiltrated precious metal precursors (e.g., acid or salt forms of chloroplatinate, chloropalladate, chloroaurate) into the polar domains of self-assembled poly(styrene-block-2-vinyl pyridine) (PSbP2VP) followed by O 2 and Ar plasma treatment to remove the polymer template and reduce the metals to yield Pt, Pd, and Au nanowires on silicon wafers.…”

“…This latter pathway involving PS b PVP/NMP + is previously unreported and leads to larger metal loadings and taller mesoscale structures over the former, conventional pathway involving PS b PVP. [ 8,30–33 ] The terms PS b PVP/NMP + and PS b PVP refer to alkylated and non‐alkylated BCP variants with either 2‐vinylpyridine and 4‐vinylpyridine repeat units and A‐B diblock and A‐B‐A triblock configurations.…”