Researchers at Korea University develop high-performance textile-based electrodes for watersplitting
Researchers at Korea University have developed high-performance, textile-based electrodes for watersplitting (WSE); the non-noblemetal-based electrodes can generate a large amount of hydrogen with low overpotentials and high operational stability. An open-access paper on their work is published in the RSC journal Energy & Environmental Science.
An electrochemical water-splitting reaction offers an effective pathway to generate hydrogen fuels and store electricity from various intermittent but renewable energy sources. Recently, substantial efforts have been devoted to fabricating high-performance and low-cost water-splitting electrodes that can generate a large amount of hydrogen fuels per unit area with low overpotentials and long-term stability under alkaline conditions. To achieve this goal, non-noble metal-based catalysts have been introduced onto porous substrates with large surface area using solution processes.
However, non-uniform coating of electrocatalysts onto porous substrates, unfavorable interfacial interactions between electrocatalysts and substrates, and/or relatively low electrical conductivity of electrocatalysts notably increased the overpotentials of electrodes, and simultaneously induced unstable operation at high current density.
To address these problems, a carbonization/interfacial assembly-driven electroplating approach was applied to highly porous silk textiles. Benefiting from the fine control of the electrocatalytic deposition on the carbonized silk fibrils, insulating silks were almost perfectly converted to high-performance water-splitting electrodes with bulk metal-like conductivity, large electrocatalytic area, extremely low overpotentials, and unprecedently high operation stability.
Our approach can provide a promising tool for developing high-performance electrodes for water electrolyzers and other electrochemical energy devices.—Mo et al.
The team first converted silk textiles to carboxylic acid-functionalized conductive textiles using carbonization and a subsequent acid treatment. Then, they assembled amine linkers onto the conductive textiles to achieve favorable interfacial interactions with electrocatalysts.
For a hydrogen evolution reaction (HER) electrode, they electroplated nickel (Ni) onto the interface-modified textile, while to prepare an oxygen evolution reaction (OER) electrode, they additionally electroplated NiFeCo onto the Ni-electroplated textile.
Schematic illustration of the carbonization/interfacial assembly-driven electroplating approach to fabricate water-splitting electrodes. Mo et al.
These HER and OER electrodes exhibited extremely low overpotentials in alkaline media (12 mV at 10 mA cm−2 for the HER and 186 mV at 50 mA cm−2 for the OER), outperforming the conventional non-noble metal-based electrodes.
The overall-water-splitting reaction of full-cell electrodes was stably maintained at a remarkably high current density of 2000 mA cm−2 and a low cell voltage of 1.70 V.
Jeongmin Mo, Younji Ko, Young Soo Yun, June Huh and Jinhan Cho (2022) “A carbonization/interfacial assembly-driven electroplating approach for water-splitting textile electrodes with remarkably low overpotentials and high operational stability” Energy Environ. Sci. doi: 10.1039/d2ee01510b