Dr Kaye Minkyung Kang is a new lecturer, ARC DECRA fellow, and research group leader in the School of Chemistry. Her research centres on electrochemistry, probing electrode-electrolyte interfaces at the nanoscale to develop next-generation energy materials.
Unveiling Structure-Activity Relationships of Electrodes via Unique Nanotechnology
Electrochemistry, once a small branch of physical chemistry, has now permeated every aspect of our lives, including the smartphones we carry. With growing interest from scientists, it has become an interdisciplinary field spanning science and engineering. Over time, electrochemistry has evolved significantly and opened a new era for nanotechnology, revolutionising our understanding of chemical processes at the nanoscale.
Electrochemistry traces its origins back to the 18th century when Alessandro Volta created the first true battery, known as the “Voltaic pile.” This revolutionary invention generated electricity through chemical reactions at copper and brass plates immersed in salty water. Fast forward to 2019, three Nobel Prize laureates, B. Goodenough, M. Stanley Whittingham, and Akira Yoshino, were awarded for their ground-breaking work on lithium-ion batteries.
Electrochemistry extends beyond batteries and finds applications in diverse areas such as metal extraction from ore, chemical synthesis, corrosion prevention, water purification, renewable fuel generation, understanding neural processes, and monitoring your glucose levels in everyday life. Its significance has been further highlighted in recent years due to its potential to mitigate climate change, offering the ability to produce electricity through various chemical reactions and even convert CO2 directly into valuable chemical resources. It is truly an indispensable aspect of our modern existence.
At its core, electrochemistry is a dynamic chemical process that occurs at the interface where a solid electrode meets a liquid electrolyte containing solvent and charged ions. A breakthrough occurred when electrochemists gained the ability to control the chemical dynamics at the electrode surface by applying voltage. This allowed manipulation of chemical reactions at the interface over time. Researchers soon realised that the surface structure of the electrode plays a crucial role in determining reaction kinetics, as specific structure can reduce activation energy and catalyse reactions. Identifying optimal structures is crucial for designing highly efficient electrode materials that contribute to energy efficiency and sustainability.
The electrode surface structure is inherently heterogeneous, comprising various crystal orientations and surface defects, which significantly influence electrochemical processes. Traditional electrochemical measurements involved immersing the entire electrode in the electrolyte, yielding averaged electrochemical responses and making it difficult to discern structure-activity relationships. Since the 1980s, electrochemists worldwide have been dedicated to developing new technologies capable of measuring electrochemical signals at the nanoscale, down to the level of a single molecule.
As part of this global effort, I have been actively involved in developing a unique electrochemical imaging technology that enables simultaneous visualisation of both structure and activity at scales as small as a few tens of nanometres. The true value of this technology is fully realized when it synergizes with other complementary nanotechnologies, allowing for a direct correlation between structure and (electro)chemical activity. Our recent findings, in collaboration with teams from Stanford University, have unambiguously revealed structure-activity relationships in green energy conversion materials (Nature 2021, 593, 67-73; Nature Materials 2021, 20, 1000-1006). With support from the Australian Research Council and the School of Chemistry, I have established a state-of-the-art nanotechnology platform, the first of its kind in Australia. This platform will serve as a pivotal point for materials design in energy conversion and storage applications.
Electrochemistry’s influence on our daily lives cannot be overstated. By uncovering the intricate relationship between electrode structure and activity, we can unlock new possibilities for designing advanced electrode materials, thereby enhancing energy efficiency and sustainability. With the advent of cutting-edge nanotechnology, we are poised to make significant strides in this field, and the establishment of our state-of-the-art platform marks an exciting milestone in Australia’s scientific landscape.