Polyoxometalate-based plasmonic electron sponge membrane for nanofluidic osmotic energy conversion

Chengcheng Zhu; Li Xu; Yazi Liu; Jiang Liu; Jin Wang; Hanjun Sun; Ya-Qian Lan; Chen Wang

doi:10.1038/s41467-024-48613-6

Polyoxometalate-based plasmonic electron sponge membrane for nanofluidic osmotic energy conversion

Nat Commun. 2024 May 17;15(1):4213. doi: 10.1038/s41467-024-48613-6.

Authors

Chengcheng Zhu¹, Li Xu¹, Yazi Liu², Jiang Liu³, Jin Wang¹, Hanjun Sun¹, Ya-Qian Lan^{4

5}, Chen Wang⁶

Affiliations

¹ Jiangsu Key Laboratory of New Power Batteries, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, 210023, China.
² School of Environment, Jiangsu Engineering Lab of Water and Soil Eco-remediation, Nanjing Normal University, Nanjing, 210023, China.
³ School of Chemistry, South China Normal University, Guangzhou, 510006, China.
⁴ Jiangsu Key Laboratory of New Power Batteries, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, 210023, China. yqlan@m.scnu.edu.cn.
⁵ School of Chemistry, South China Normal University, Guangzhou, 510006, China. yqlan@m.scnu.edu.cn.
⁶ Jiangsu Key Laboratory of New Power Batteries, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, 210023, China. wangchen@njnu.edu.cn.

Abstract

Nanofluidic membranes have demonstrated great potential in harvesting osmotic energy. However, the output power densities are usually hampered by insufficient membrane permselectivity. Herein, we design a polyoxometalates (POMs)-based nanofluidic plasmonic electron sponge membrane (PESM) for highly efficient osmotic energy conversion. Under light irradiation, hot electrons are generated on Au NPs surface and then transferred and stored in POMs electron sponges, while hot holes are consumed by water. The stored hot electrons in POMs increase the charge density and hydrophilicity of PESM, resulting in significantly improved permselectivity for high-performance osmotic energy conversion. In addition, the unique ionic current rectification (ICR) property of the prepared nanofluidic PESM inhibits ion concentration polarization effectively, which could further improve its permselectivity. Under light with 500-fold NaCl gradient, the maximum output power density of the prepared PESM reaches 70.4 W m^-2, which is further enhanced even to 102.1 W m^-2 by changing the ligand to P₅W₃₀. This work highlights the crucial roles of plasmonic electron sponge for tailoring the surface charge, modulating ion transport dynamics, and improving the performance of nanofluidic osmotic energy conversion.