Interfacial Super-Assembly of Vacancy Engineered Ultrathin-Nanosheets toward Nanochannels for Smart Ion Transport and Salinity Gradient Power Conversion

Abuduheiremu Awati; Ran Yang; Ting Shi; Shan Zhou; Xin Zhang; Hui Zeng; Yaokang Lv; Kang Liang; Lei Xie; Dazhang Zhu; Mingxian Liu; Biao Kong

doi:10.1002/anie.202407491

Interfacial Super-Assembly of Vacancy Engineered Ultrathin-Nanosheets toward Nanochannels for Smart Ion Transport and Salinity Gradient Power Conversion

Angew Chem Int Ed Engl. 2024 May 12:e202407491. doi: 10.1002/anie.202407491. Online ahead of print.

Authors

Abuduheiremu Awati¹, Ran Yang¹, Ting Shi¹, Shan Zhou², Xin Zhang³, Hui Zeng³, Yaokang Lv⁴, Kang Liang⁵, Lei Xie⁶, Dazhang Zhu¹, Mingxian Liu¹, Biao Kong⁷

Affiliations

¹ Tongji University, School of Chemical Science and Engineering, CHINA.
² Qingdao University, College of Materials Science and Engineering, CHINA.
³ Fudan University, Department of Chemistry, CHINA.
⁴ Zhejiang University of Technology, College of Chemical Engineering, CHINA.
⁵ University of New South Wales, School of Chemical Engineering, CHINA.
⁶ Xian Jiaotong University, School of Life Science and Technology, CHINA.
⁷ Fudan University, Department of Chemistry, Department of Chemistry, Fudan University, Shanghai 200433, P. R. China, 200433, Shanghai, CHINA.

PMID: 38735853
DOI: 10.1002/anie.202407491

Abstract

Ion-selective nanochannel membranes assembled from two-dimensional (2D) nanosheets hold immense promise for power conversion using salinity gradient. However, they face challenges stemming from insufficient surface charge density, which impairs both permselectivity and durability. Herein, we present a novel vacancy-engineered, oxygen-deficient NiCo layered double hydroxide (NiCoLDH)/cellulose nanofibers-wrapped carbon nanotubes (VOLDH/CNF-CNT) composite membrane. This membrane, featuring abundant angstrom-scale, cation-selective nanochannels, is designed and fabricated through a synergistic combination of vacancy engineering and interfacial super-assembly. The membrane shows interlayer free-spacing of ~3.62 Å, which validates the membrane size exclusion selectivity.This strategy, validated by DFT calculations and experimental data, improves hydrophilicity and surface charge density, leading to the strong interaction with K+ ions to benefit the low ion transport resistance and exceptional charge selectivity. When employed in an artificial river water|seawater salinity gradient power generator, it delivers a high-power density of 5.35 W/m2 with long-term durability (20,000s), which is almost 400% higher than that of the pristine NiCoLDH membrane. Furthermore, it displays both pH- and temperature-sensitive ion transport behavior, offering additional opportunities for optimization. This work establishes a basis for high-performance salinity gradient power conversion and underscores the potential of vacancy engineering and super-assembly in customizing 2D nanomaterials for diverse advanced nanofluidic energy devices.

Keywords: 2D membranes; interfacial super-assembly; nanochannel; salinity gradient power conversion; vacancy-engineering.