Bioinspired Chloride-Assisted Protein Channels: Enhancing Proton Transport for Sustainable Energy Harvesting from Acidic Wastewater
Wenxiu Jiang, Xuan Ding, Zihao Huang, Xiao-Chen Feng, Meiling Wang, Xinyue Zhang, Shuyu Ying, Huanting Wang, Jun Gao, Ying Zhu, Lei Jiang
Abstract
Highly efficient proton transfer in biological processes has driven the pursuit of synthetic analogs; however, replicating high proton permeance in natural systems remains a significant challenge. Herein, inspired by the function of the ClC-ec1 protein, we report the design of Cl – -assisted proton transport channels within a hybrid membrane composed of covalent organic frameworks (COFs) integrated with aramid nanofibers (ANFs). By leveraging buffer layer-mediated interfacial polymerization and the flocculation behavior of ANF in aqueous environments, we establish robust hydrogen-bonding interactions between COFs and ANFs. The hydride material enables Cl – binding, significantly accelerating proton transport in a manner similar to that of the ClC-ec1 protein channel. In the presence of a small concentration of Cl – ions (0.1% of the proton concentration), the proton permeation rate is enhanced approximately by 3 times, reaching 9.8 mol m –2 h –2 . Notably, the membrane facilitates sustainable osmotic power generation from acidic wastewater, delivering an output power density of 434.8 W m –2 . Theoretical calculations revealed that ANF preferentially binds Cl –, promoting proton hopping and lowering the energy barrier for proton transport. This study establishes a new paradigm for bioinspired ion-assisted proton transport, presenting an approach for sustainable energy harvesting from acidic wastewater.