(Nanowerk News) Researchers at Tohoku University and Tsinghua University have introduced a next-generation model membrane electrode that promises to revolutionize basic electrochemical research. This innovative electrode, which is fabricated through a rigorous process, features a giant hollow carbon nanotube (gCNT) array in a nanoporous membrane, opening up new possibilities for energy storage and electrochemical studies.
The main breakthrough lies in the construction of these new electrodes. The researchers developed a technique for uniformly carbon coating anodic aluminum oxide (AAO) formed on an aluminum substrate, by removing the barrier layer. The resulting carbon-coated layers exhibit vertically aligned gCNTs with nanopores ranging from 10 to 200 nm in diameter and 2 µm to 90 µm in length, spanning small electrolyte molecules to large bio-related things like enzymes and exosomes.
Unlike traditional composite electrodes, these self-modeling electrodes eliminate contact between particles, ensuring minimal contact resistance – something that is important for interpreting the appropriate electrochemical behavior.
“The potential of this model’s electrodes is enormous,” said Dr. Zheng-Ze Pan, co-author of the corresponding study. “By using model membrane electrodes with a wide range of nanopore dimensions, we were able to gain deep insights into the intricate electrochemical processes occurring inside porous carbon electrodes, along with their inherent correlations to nanopore dimensions.”
In addition, gCNTs consist of low-crystalline stacked graphene sheets, offering unparalleled access to the electrical conductivity within the low-crystalline carbon walls. Through experimental measurements and utilization of an in-house temperature-programmed desorption system, the researchers built an atomic-scale structural model of the low-crystalline carbon wall, enabling detailed theoretical simulations.
Alex Aziz, who conducted the simulation portion of the study, pointed out, “Our advanced simulations provide a unique lens for estimating electron transitions in amorphous carbon, highlighting the complex mechanisms governing its electrical behavior.”
This project is led by Prof. Dr. Hirotomo Nishihara, Principal Investigator of Devices/Systems Group at the Advanced Institute for Materials Research (WPI-AIMR). These findings are detailed in Advanced Functional Materials (“Nanoporous Membrane Electrode with Orderly Array of Hollow Giant Carbon Nanotubes”).
Ultimately, this research represents a significant step forward in our understanding of amorphous carbon-based porous materials and their application in investigating various electrochemical systems.