Single-walled carbon nanotubes as a reducing agent for the synthesis of a Prussian blue-based composite: a quartz crystal microbalance study.

Yosuke Ishii,Ayar Al-Zubaidi,Shinji Kawasaki,Shinya Jindo,Yoshimitsu Taniguchi

doi:10.1039/d1na00739d

Yosuke Ishii, Ayar Al-Zubaidi + Show 3 more

Open Access

https://doi.org/10.1039/d1na00739d

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Journal: Nanoscale Advances	Publication Date: Jan 1, 2022
Citations: 3	License type: CC BY 3.0

Affiliation: Nagoya Institute of Technology

Abstract

We investigated the synthesis mechanism of Prussian blue (PB) crystals supported on single-walled carbon nanotubes (SWCNTs), by performing in situ quartz crystal microbalance (QCM) measurements to probe the change in the electrode mass during the reaction, and using photoirradiation at designated stages of the process. We found that in contrast to existing hypotheses, light irradiation played no role in the synthesis process of Prussian blue on SWCNTs. On the other hand, the number of electrons transferred per one mole of the obtained product, and the number of electrons transferrable from SWCNTs, calculated from the density of states (DOS) of the SWCNTs in the sample, both favor the hypothesis of the reaction being triggered by direct electron transfer from SWCNTs to Fe3+, which occurs because of the energy difference between the Fermi level of SWCNTs and redox potential of Fe3+ ions.

Highlights

The market for lithium ion batteries continues to expand beyond portable electronics and electric/hybrid vehicles, requiring the device performance to sometimes accommodate a range of extreme temperatures spanning from À40 to 70 C and wider.[1,2,3] In particular, the use of lithium ion batteries in cold climates, space missions, military and other low temperature applications emphasizes the need to improve the performance of lithium ion batteries at sub-zero temperatures, at which the charging capability of the system drops considerably due to multiple possible factors, including most notably the deterioration in the lithium ion diffusion kinetics at low temperature.[4,5] This problem sparked research efforts aiming to design electrode and electrolyte materials capable of delivering consistently high performance in wide temperature ranges, by modifying a number of existing battery materials or exploring new materials for the purpose.[6,7,8,9]Among the materials being investigated towards that end are the class of cyano-based coordination materials called Prussian blue analogues (PBAs)
We probed the synthesis process using quartz crystal microbalance (QCM) measurements to track the change in the electrode mass resulting from the formation of Prussian blue (PB) particles on the surface of single-walled carbon nanotubes (SWCNTs), and used light irradiation at designated stages of the synthesis process to test the hypothesis of spontaneous charge transfer versus the mechanism of photo-induced charge transfer proposed in some studies.[24,40,41]
We calculated the number of electrons transferred in the synthesis reaction from the PB : SWCNT mass ratio obtained from thermogravimetric analysis (TGA) measurements (1.8 : 1), and the number of electrons required to synthesize 1 mol of PB

Summary

Introduction

The market for lithium ion batteries continues to expand beyond portable electronics and electric/hybrid vehicles, requiring the device performance to sometimes accommodate a range of extreme temperatures spanning from À40 to 70 C and wider.[1,2,3] In particular, the use of lithium ion batteries in cold climates, space missions, military and other low temperature applications emphasizes the need to improve the performance of lithium ion batteries at sub-zero temperatures, at which the charging capability of the system drops considerably due to multiple possible factors, including most notably the deterioration in the lithium ion diffusion kinetics at low temperature.[4,5] This problem sparked research efforts aiming to design electrode and electrolyte materials capable of delivering consistently high performance in wide temperature ranges, by modifying a number of existing battery materials or exploring new materials for the purpose.[6,7,8,9]Among the materials being investigated towards that end are the class of cyano-based coordination materials called Prussian blue analogues (PBAs).

Results

Conclusion