Pentagon-Enriched Carbon Materials: Controlled Synthesis and Electrochemical Applications

ConspectusCarbon-based materials are widely investigated as sustainable electrodes for energy conversion, storage, and environmental remediation. Yet, pristine carbons with perfect sp²-hybridized hexagonal lattices usually exhibit limited electrochemical reactivity. This is primarily due to their ordered layered crystal structure and intrinsic electronic neutrality, which results in a lack of unsaturated coordination sites required for small-molecule activation. Therefore, the structural engineering of the carbon matrix is highly critical to addressing this bottleneck.Introducing pentagon motifs into carbon frameworks serves as an effective approach to breaking the planar lattices and electronic neutrality of pristine carbon. Specifically, the pentagon motifs induce geometric curvature and electronic modulation, thereby endowing the material with excellent performance in a range of electrochemical applications. Despite this potential, the controlled synthesis of pentagon-enriched carbons remains a long-standing challenge.To tackle this issue, our group has leveraged the inherent carbon pentagonal rings in fullerenes as a unique entry point, pioneering pathways for the construction and precise regulation of pentagons in carbon frameworks. Over the past decade, we have focused on developing carbon materials with intrinsic pentagon motifs and made progress in their controllable synthesis, functional modulation, and multilevel structural evolution.In this Account, we will summarize our recent progress on the controlled synthesis of pentagon-enriched carbon materials and their electrochemical applications. We first present promising practices to achieve the controlled incorporation of pentagon units into extended carbon frameworks under fullerene-reconstructed methodologies. We further highlight the advanced characterization techniques and theoretical investigations in determining the presence and functions of pentagonal rings in carbon frameworks. Based on these structural insights, we discuss their properties in electrochemical processes and highlight their relevance to applications. Finally, perspectives on the challenges and future opportunities of this emerging field are proposed. The strategies and insights presented herein not only establish a foundational framework for pentagon engineering in carbon materials but also offer guidelines for designing functional nanomaterials across energy and environmental applications.