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

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.

Well‐Defined Conjugated Reticular Oligomer “Blood Cells” and Conducting Polymer “Neurons” Constructing “Muscle”‐Biomimetic Electrocatalysts for Water Electrolysis

“…Inspired by the distinct geometric structure and preeminent HER performance of CROs-Ru, CROs-Ru are further researched for OER in 1 m KOH aqueous solution. [11,14,24,32] at 10 mA cm −2 . This may be due to the stacked bulk [12,13,32f,33] www.afm-journal.de www.advancedsciencenews.com…”

“…a) Bulk COFs-Ru and CROs-Ru: over-potential; b) Tafel slopes; c) R ct ; d) C dl ; e) mass activity and f) TOF values. g) HER performance of PEDOT/CRO OH -8-Ru and other reported COFs [11,14,24,32].…”

Interfacial Synthesis of 2D COF Thin Films

“…By heating the reactor to a specified temperature to control the evaporation of aldehyde monomers, the aldehyde monomers condense on the surface covered by amine monomers and polymerize with them, high-quality monolayer imine COF films can be prepared at the air/solid interface [41]. Recently, Yunqi Liu et al reported the preparation of large area imine PyTTA-TPA COF film with controllable thickness by gas-phase induced conversion in a CVD system (Figure 8d) [42]. The assembly process is achieved by reversible reaction between 4,4′,4″,4″′-(1,3,6,8-Tetrakis(4-aminophenyl)pyrene (PyTTA) film and terephthalaldehyde (TPA) vapor.…”

Photoresponse of CVD grown crystalline quantum dot-embedded covalent organic framework thin film

“…[50][51][52] Remarkably, as a new development, Liu et al.recently reported a vapor-induced process for largescale synthesis of 2D-COF lms on several substrates. 53 Another group reported COF-TpPa1 membranes fabrication by CVD method and used the membranes for dye separation. 50 COF-366 is one of the pioneering and promising porphyrin based-COF with very high charge carrier mobility reported by Yaghi and co-workers and later several research groups presented applications of COF-366.…”