High Throughput Atom-by-Atom Electrochemistry
Lead Research Organisation:
University of Warwick
Department Name: Chemistry
Abstract
Electrochemistry has a long history, but has never been more important than today, and is one of the most exciting branches of science. Electrochemistry is at the centre of energy storage and utilisation technologies, in batteries, fuel cells and solar cells. It is finding expanding applications in sensing and diagnostic platforms, and presenting new possibilities for the creation of nanomaterials, functionalised surfaces and in electrosynthesis. These technologies have emerged because of inquisitive science. A famous example is the development of the battery by Volta more than two centuries ago, not as a means of energy storage and utilisation, but to counter an argument with Galvani about the origin of "animal electricity". Yet, where would we be today without the battery?
Fundamental elementary electrochemical processes are extremely challenging to study and are limited by conventional experimental capability, which tends to focus on the macroscopic (applications) world or (at best, but rare) mesoscale. We intend to make and prove the smallest possible electrode: an individual single atom, produced by the electro-reduction of a single ion. We shall determine the conditions whereby this process occurs and study electrochemical processes at the resulting single atom electrode. This ambitious goal will be achieved by marrying recent developments in nanoscale electrochemistry and imaging science. We shall use nanoscale pipette probes in a scanning electrochemical cell microscopy (SECCM) format to deliver metal ions in a controllable way to a series of tiny regions on a boron doped diamond transmission electron microscopy (TEM) grid, which will serve as an electrode to reduce the impinging ions to atoms. This grid will then be analysed by aberration corrected-scanning transmission electron microscopy (ac-STEM). We shall further explore and prove a bottom-up approach for the production of nanoclusters atom-by-atom. We shall investigate electrocatalytic processes at these single atom and few-atom electrodes, to understand how electrochemical processes scale from the smallest possible size upwards.
The beauty of the proposed approach is that after electrodeposition in one spot by SECCM, the nanopipette is withdrawn, translated laterally by a small distance and landed in a fresh, new spot for the next electrodeposition, in a process that is repeated to create a scanned array, typically of several thousand individual spots on a reasonable timescale. Thus, it will be possible to execute several thousand experiments (trials) in an experimental run that will allow a wide parameter space to be explored and analysed by ac-STEM in one scan experiment. This unique high throughput combinatorial microscopy approach is crucial for obtaining statistics on an inherently stochastic process and to provide direct proof of the experimental outcome.
(i) Deposition of single atoms. We shall study electrodeposition under conditions where the average outcome is a single atom on a surface, bounded by the limits of the stochastic nature of single molecule diffusion.
(ii) Atom-by-atom assembly of metal nanostructures and clusters. Our studies will provide unprecedented insight into nucleation and growth processes generally, at the very earliest stages, not previously accessible to investigation.
(iii) Electrochemical measurements will reveal electrode kinetics at individual atom scale electrocatalytic entities, and also insights on mass transport and double layer effects at this scale.
(iv) If time permits, we shall investigate whether it is possible to make individual bimetallic nano-alloys (of just 2 or few atoms).
Our work takes experimental electrochemistry to a new domain: the atom lengthscale and nanoscale timescale.
Fundamental elementary electrochemical processes are extremely challenging to study and are limited by conventional experimental capability, which tends to focus on the macroscopic (applications) world or (at best, but rare) mesoscale. We intend to make and prove the smallest possible electrode: an individual single atom, produced by the electro-reduction of a single ion. We shall determine the conditions whereby this process occurs and study electrochemical processes at the resulting single atom electrode. This ambitious goal will be achieved by marrying recent developments in nanoscale electrochemistry and imaging science. We shall use nanoscale pipette probes in a scanning electrochemical cell microscopy (SECCM) format to deliver metal ions in a controllable way to a series of tiny regions on a boron doped diamond transmission electron microscopy (TEM) grid, which will serve as an electrode to reduce the impinging ions to atoms. This grid will then be analysed by aberration corrected-scanning transmission electron microscopy (ac-STEM). We shall further explore and prove a bottom-up approach for the production of nanoclusters atom-by-atom. We shall investigate electrocatalytic processes at these single atom and few-atom electrodes, to understand how electrochemical processes scale from the smallest possible size upwards.
The beauty of the proposed approach is that after electrodeposition in one spot by SECCM, the nanopipette is withdrawn, translated laterally by a small distance and landed in a fresh, new spot for the next electrodeposition, in a process that is repeated to create a scanned array, typically of several thousand individual spots on a reasonable timescale. Thus, it will be possible to execute several thousand experiments (trials) in an experimental run that will allow a wide parameter space to be explored and analysed by ac-STEM in one scan experiment. This unique high throughput combinatorial microscopy approach is crucial for obtaining statistics on an inherently stochastic process and to provide direct proof of the experimental outcome.
(i) Deposition of single atoms. We shall study electrodeposition under conditions where the average outcome is a single atom on a surface, bounded by the limits of the stochastic nature of single molecule diffusion.
(ii) Atom-by-atom assembly of metal nanostructures and clusters. Our studies will provide unprecedented insight into nucleation and growth processes generally, at the very earliest stages, not previously accessible to investigation.
(iii) Electrochemical measurements will reveal electrode kinetics at individual atom scale electrocatalytic entities, and also insights on mass transport and double layer effects at this scale.
(iv) If time permits, we shall investigate whether it is possible to make individual bimetallic nano-alloys (of just 2 or few atoms).
Our work takes experimental electrochemistry to a new domain: the atom lengthscale and nanoscale timescale.
People |
ORCID iD |
Pat Unwin (Principal Investigator) | |
Julie MacPherson (Co-Investigator) |
Publications
Swinya D
(2023)
Activation of Glassy Carbon Surfaces by Alkaline Anodization Enhances Dopamine Adsorption and Electron-Transfer Kinetics
in ChemElectroChem
Cremin K
(2023)
Can Single Cell Respiration be Measured by Scanning Electrochemical Microscopy (SECM)?
in ACS measurement science au
Unwin P
(2022)
Concluding remarks: next generation nanoelectrochemistry - next generation nanoelectrochemists.
in Faraday discussions
Martín-Yerga D
(2023)
Correlative co-located electrochemical multi-microscopy
in Current Opinion in Electrochemistry
Varhade S
(2023)
Elucidation of alkaline electrolyte-surface interaction in SECCM using a pH-independent redox probe
in Electrochimica Acta
Tetteh E
(2023)
Fast Li-ion Storage and Dynamics in TiO 2 Nanoparticle Clusters Probed by Smart Scanning Electrochemical Cell Microscopy
in Angewandte Chemie International Edition
Xu X
(2023)
Interfacial Chemistry Effects in the Electrochemical Performance of Silicon Electrodes under Lithium-Ion Battery Conditions.
in Small (Weinheim an der Bergstrasse, Germany)
Martín-Yerga D
(2023)
Link between anisotropic electrochemistry and surface transformations at single-crystal silicon electrodes: Implications for lithium-ion batteries
in Natural Sciences
Tao B
(2023)
Multiscale Electrochemistry of Lithium Manganese Oxide (LiMn2O4): From Single Particles to Ensembles and Degrees of Electrolyte Wetting.
in ACS sustainable chemistry & engineering
Wahab OJ
(2022)
Nanoscale Visualization of Electrochemical Activity at Indium Tin Oxide Electrodes.
in Analytical chemistry
Description | We have successful implemented a strategy whereby a bespoke conducting diamnd TEM grid can be used as an electrode substrate for scanning electrochemical cell microscopy (SECCM) to enable the analysis of surfaces after electrochemistry with atom-resolution. Using this method we have: (i) revealed new information on the nucleation and growth of metal nanoparticles; and (ii) determined conditions where single atom arrays (catalysts) can be deposited. |
Exploitation Route | 1. The diamond TEM grids may become available for wider use in the community. 2. The work further diversifies the use of SECCM (invented in the PI's group at Warwick) for which the community of users is growing rapidly. 3. Although early, the work presents new ways to fabricate single atom electrocatalysts by electrochemistry rather than chemical means, as presently used. |
Sectors | Energy |
Description | Collaboration with Andre Geim and Marcelo Lozada-Hidalgo (University of Manchester) |
Organisation | University of Manchester |
Department | National Graphene Institute |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | We applied the state of the art SECCM technique to understand the charge transfer properties of suspended graphene, in particular identifying sites for proton transport |
Collaborator Contribution | Supplied well characterised devices and samples, deep engagement in the science and data, including modelling through additional collaboration. |
Impact | A paper is under review/revision. |
Start Year | 2021 |
Description | Collaboration with WMG, Warwick |
Organisation | University of Warwick |
Department | Warwick Manufacturing Group |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Through the award of this funding, and the unique experimental capability we will establish, we are creating new collaborations with WMG (Geoff West and Mel Loveridge) to do some pump priming experiments. |
Collaborator Contribution | The link is through Pat Unwin, Warwick Chemistry. |
Impact | Just started. |
Start Year | 2020 |
Description | Concluding Remarks, Next Generation Nanoelectrochemistry Faraday Discussion, Dec 2021 |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | I was invited to give Concluding Remarks, Next Generation Nanoelectrochemistry Faraday Discussion, Dec 2021. The meeting was held online and reached a large international audience. I summarised the key developments from the meeting, placing the work in a historical context. I further used this opportunity to predict how the field of nanoelectrochemistry may develop in the future. |
Year(s) Of Engagement Activity | 2021 |
Description | Distinguished Lecture, iNano, Aarhus |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Postgraduate students |
Results and Impact | Invited lecture as part of the iNano Distinguished Lecture series, leading to dissemination of our activities in SECCM to a diverse audience in nanoscience. |
Year(s) Of Engagement Activity | 2022 |
Description | Invited Keynote at 15th International Fischer Symposium, Kloster Seeon, Germany |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Postgraduate students |
Results and Impact | I have an invited keynote at 15th International Fischer Symposium, Kloster Seeon, Germany. This meeting covers a broad range of electrochemistry and I was able to raise awarenes of our recent work on SECCM and high resolution electrochemical imagining. |
Year(s) Of Engagement Activity | 2022 |
Description | Invited lecture - Nanoscience Days, Finland |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Postgraduate students |
Results and Impact | I was an invited speaker at the longrunning Nanoscience Days conference, University of Jyväskylä. I was able to present our SECCM studies to a broad audience in nanoscience, raising awareness of our innovative methods. |
Year(s) Of Engagement Activity | 2022 |