Chemistry of Two-Dimensional Materials for Sustainable Energy and Catalysis

Abstract

Two-dimensional (2D) materials form a large and diverse family of materials with extremely rich compositions, ranging from graphene to complex transition metal derivatives. They exhibit unique physical, chemical, and electronic properties, making 2D materials highly promising in the fields of sustainable energy storage and electrocatalysis. Although significant progress has been made in the design and performance optimization of 2D materials, challenges persist, particularly in energy storage and electrocatalysis. A key issue is the restacking or aggregation of these materials in the powder form, which hinders ion transport and reduces their overall performance by limiting the effective surface area. In this Account, we delve into the latest advancements made by our team in the chemistry of 2D materials toward sustainable electrochemical energy storage and catalysis. We begin by highlighting some of the representative 2D materials developed by our team, such as fluorine-modified graphene and transition metal telluride nanosheets. These materials, with their atomic-scale thickness, offer significant advantages over traditional bulk materials by circumventing issues such as limited active surface area, extended ion transport pathways, and complex manufacturing processes, thereby providing innovative approaches for the development of high-performance materials. Next, the key synthesis strategies that have been pivotal in our research are summarized. Techniques such as electrochemical exfoliation, solid-state lithiation and exfoliation, and ion-adsorption chemical strategies have enabled precise control over the ionic and electronic conductivities, lateral dimensions, and internal atomic configurations of 2D materials. These methodologies not only facilitate the preparation of 2D materials with tailored properties, but also support the scalable production of high-quality materials. Furthermore, we outline the broad applications of 2D energy materials across various domains. In alkali-based batteries, these materials have been instrumental in enhancing battery performance, including extending the cycle life and improving the charge–discharge efficiency. They also contribute to increased energy and power densities in aqueous-based batteries and supercapacitor–battery hybrid devices. In the realm of metal-free anodes, they play a crucial role in inhibiting metal dendrite growth, thereby enhancing battery safety. Additionally, in energy catalysis, they demonstrate superior catalytic activity, promoting efficient energy conversion. In microscale electrochemical energy storage devices, they meet the demands for high power and energy density, propelling the advancement of miniaturized energy storage solutions. Lastly, we address the critical challenges confronting 2D energy materials and offer a perspective on future directions. While significant progress has been achieved in 2D material research, challenges persist in synthesis, performance optimization, and fundamental understanding. In synthesis, the issues related to nanosheet stacking and production efficiency need to be resolved. Performance optimization requires further enhancements in the material stability and electrochemical properties. Fundamental research must deepen our understanding of the structure–property relationships in these materials. As research progresses, 2D materials are poised to achieve further breakthroughs in high-performance energy storage and electrocatalysis, offering viable solutions to global energy challenges.