Two-dimensional covalent organic framework films prepared on various substrates through vapor induced conversion

Minghui Liu; Youxing Liu; Jichen Dong; Yichao Bai; Wenqiang Gao; Shengcong Shang; Xinyu Wang; Junhua Kuang; Changsheng Du; Ye Zou; Jianyi Chen; Yunqi Liu

doi:10.1038/s41467-022-29050-9

Two-dimensional covalent organic framework films prepared on various substrates through vapor induced conversion

Nat Commun. 2022 Mar 17;13(1):1411. doi: 10.1038/s41467-022-29050-9.

Authors

Minghui Liu^{1

2}, Youxing Liu^{1

2}, Jichen Dong^{1

2}, Yichao Bai^{1

2}, Wenqiang Gao^{1

2}, Shengcong Shang^{1

2}, Xinyu Wang^{1

2}, Junhua Kuang^{1

2}, Changsheng Du^{1

2}, Ye Zou^{1

2}, Jianyi Chen^{3

4}, Yunqi Liu^{5

6}

Affiliations

¹ Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, 100190, Beijing, PR China.
² University of Chinese Academy of Sciences, 100049, Beijing, PR China.
³ Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, 100190, Beijing, PR China. chenjy@iccas.ac.cn.
⁴ University of Chinese Academy of Sciences, 100049, Beijing, PR China. chenjy@iccas.ac.cn.
⁵ Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, 100190, Beijing, PR China. liuyq@iccas.ac.cn.
⁶ University of Chinese Academy of Sciences, 100049, Beijing, PR China. liuyq@iccas.ac.cn.

Abstract

Covalent organic frameworks (COFs) can exhibit high specific surface area and catalytic activity, but traditional solution-based synthesis methods often lead to insoluble and infusible powders or fragile films on solution surface. Herein we report large-area -C=N- linked two-dimensional (2D) COF films with controllable thicknesses via vapor induced conversion in a chemical vapor deposition (CVD) system. The assembly process is achieved by reversible Schiff base polycondensation between PyTTA film and TPA vapor, which results in a uniform organic framework film directly on growth substrate, and is driven by π-π stacking interactions with the aid of water and acetic acid. Wafer-scale 2D COF films with different structures have been successfully synthesized by adjusting their building blocks, suggesting its generic applicability. The carrier mobility of PyTTA-TPA COF films can reach 1.89 × 10^-3 cm² V^-1 s^-1. When employed as catalysts in hydrogen evolution reaction (HER), they show high electrocatalytic activity compared with metal-free COFs or even some metallic catalysts. Our results represent a versatile route for the direct construction of large-area uniform 2D COF films on substrates towards multi-functional applications of 2D π-conjugated systems.