Freestanding gm-thin nanomesh electrodes exceeding 100x current density enhancement for high-throughput electrochemical applications

Nanomeshes (NMs), regularly interconnected 3D nanowire-networks, obtained from electroplating in rationally designed alumina templates, are attractive for numerous fields due to their extremely high surface area and porosity. Until now, non-porous support substrates were required to provide sufficient mechanical robustness to the highly porous NM. However, to exploit these compelling nano -architectures as freestanding electrodes in electrochemical flow cells, e.g. water electrolysis, it is essential that the nanowire-network is accessible from all sides requiring a porous support structure. To demonstrate the advantage of the high volumetric NM surface area of 26 m2/cm3 for water electrolysis up to 1 A/cm2, we monolithically integrated a nickel NM with an open support grid in a facile and up -scalable fabrication flow. The freestanding NM electrodes show beyond state-of-the-art performance for the alkaline hydrogen-and oxygen evolution reaction (HER and OER), with over 100x enhanced current densities in respect to planar nickel. Interestingly, the regular nano-architecture of the electrodes causes an intrinsic catalytic effect for the HER. The high potential of these novel 4 gm thin electrodes toward high-throughput electrochemical applications is shown by the significant 400 mV lower over -potential compared to commercial 1.6 mm thick nickel foams (<0.01 m2/cm3) in the alkaline anion -exchange membrane water electrolysis.(c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

Nanomeshes are interconnected 3D nanowire-networks with high surface area and porosity, which have potential applications in various fields. By integrating nanomeshes with an open support grid, they can be used as freestanding electrodes in electrochemical flow cells, showing superior performance compared to existing technologies.