Anisotropic Superprotonic Conduction in a Layered Single-Component Hydrogen-Bonded Organic Framework with Multiple In-Plane Open Channels

Hydrogen-bonded organic frameworks (HOFs) are promising proton conductive materials because of their inherent and abundant hydrogen-bonding sites. However, most superprotonic-conductive HOFs are constructed from multiple components to enable favorable framework architectures and structural integrity. In this contribution, layered HOF-TPB-A₃ with a single component is synthesized and exfoliated. The exfoliated nanoplates exhibited anisotropic superprotonic conduction, with in-plane proton conductivities reaching 1.34 × 10⁻² S cm⁻¹ at 296 K and 98% relative humidity (RH). This outperforms the previously reported single-component HOFs and is comparable with the state-of-the-art multiple-component HOFs. The high and anisotropic proton conductive properties can be attributed to the efficient proton transport along multiple open channels parallel to their basal planes. Moreover, an all-solid-state (ASS) proton rectifier device is demonstrated by combining HOF-TPB-A₃ and a hydroxide ion-conducting layered double hydroxide (LDH). This work suggests that single-component HOFs with multiple open channels offer more opportunities as versatile platforms for proton conductors, making them promising candidates for conducting media in protonic devices.