Polyhedral Crystal Films of Covalent Organic Frameworks

Polyhedral Crystal Films of Covalent Organic Frameworks

Journal of the American Chemical Society

10.1021/jacs.5c07737

https://doi.org/10.1021/jacs.5c07737

Xiansong Shi, Qixing Liu, Haipei Shao, Chengjun Kang, He Li, Wen-Hua Li, Anwesha Mukherjee, Junyu Ren, Nengxiu Zhu, Wei Zhao, Dongchen Shi, Zhaoqiang Zhang, Yong Wang, Ming Lin, Dan Zhao

Covalent organic frameworks

29 July 2025

Shi, X., Liu, Q., Shao, H., Kang, C., Li, H., Li, W.-H., Mukherjee, A., Ren, J., Zhu, N., Zhao, W., Shi, D., Zhang, Z., Wang, Y., Lin, M., & Zhao, D. (2025). Polyhedral Crystal Films of Covalent Organic Frameworks. Journal of the American Chemical Society, 147(32), 29130–29141. https://doi.org/10.1021/jacs.5c07737

Porous crystal films offer great potential for tackling energy and environmental challenges. However, despite over a decade of intensive research, covalent organic framework (COF) films exhibiting polyhedral textures reflective of their crystalline nature remain exceedingly rare. Here we present a scalable and adaptable biphasic strategy to synthesize pyrene (Py)-COF polyhedral crystal films with exceptional crystalline order under ambient conditions. This method enables precise control over polycrystal formation in solution and crystal growth on substrates, yielding Py-COF polyhedral films with tunable nanometer-scale thicknesses on a 4 in. wafer scale. Among them, a Py-1P film achieves a record-high Brunauer−Emmett−Teller surface area reported for COF films with comparable pore sizes alongside remarkable chemical stability. Real-space electron microscopy reveals previously unreported details of the growth of COF crystal films. These polyhedral crystal films show anisotropic thermal responses along the [001] lattice direction, with dynamically adaptive thermal expansion coefficients of (1.64−2.15) × 10−4 K−1. Through sensor testing, we correlate film crystallinity with device performance and longevity. This research expands the boundaries of COF films, revealing tremendous possibilities to advance film science and its applications.

Publisher Copyright

This research / project is supported by the Centre for Hydrogen Innovations - NA
Grant Reference no. : CHI-P2024-01

This research / project is supported by the Ministry of Education - Academic Research Fund Tier 2
Grant Reference no. : MOE-T2EP10122-0002

This research / project is supported by the Agency for Science, Technology and Research - NA
Grant Reference no. : U2102d2004 and U2102d2012

This research / project is supported by the National Research Foundation Singapore - Competitive Research Programme, NRF Investigatorship
Grant Reference no. : NRF-CRP26-2021RS-0002 and NRF-NRFI08-2022-0008

This research / project is supported by the Science and Technology Support Program of Jiangsu Province - NA
Grant Reference no. : BZ2022056

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of the American Chemical Society, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see 10.1021/jacs.5c07737.

https://oar.a-star.edu.sg/communities-collections/articles/22674

0002-7863
1520-5126

Institute of Materials Research and Engineering