posted on 2020-03-18, 18:06authored byJaeyong Lee, Avnish Kumar Mishra, Chungryong Choi, Dokyoung Kim, Eun Young Kim, Kijung Yong, Jin Kon Kim
We fabricated 3D
nanoporous metal structures from poly(2-vinylpyridine)-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.