2D Clay Nanofluidic Pairs With Opposite Ion Selectivity for Constructing Salinity-Gradient Cells

Abstract

The membrane-based reverse electrodialysis (RED) is considered as the most promising technique for salinity-gradient energy harvesting. However, the high cost and difficult processing of traditional membrane materials usually limit their development in the field. Herein, a salinity-gradient cell is constructed based on a group of anion- and cation-selective 2D clay nanofluidic membranes. The opposite surface charge and confined 2D nanofluidic channels contribute to the opposite ion selectivity of the two membranes. For constructing the salinity-gradient cell, a superposed electrochemical potential difference is created by complementing the diffusion of oppositely charged ions, and an output power density of up to 5.48 W m⁻² can be obtained at a salinity gradient of 0.5/0.01 M NaCl without the contribution of electrode material redox reaction, superior to other existing natural nanofluidic RED systems to our best knowledge. Furthermore, the output voltage of the cell can reach 1.8 V by connecting 15 tandem LM-RED stacks under artificial seawater and river water, which can power the electronic devices. According to detailed life cycle assessments, the fabrication of 2D clay nanofluidic pairs achieves a significant reduction in resource consumption by 90%, a decrease in greenhouse gas emissions by 90%, and a notable reduction in production costs by 67% compared with the classical 2D nanofluidics, promising good sustainability and paves the way for clay-based membranes in RED devices for the salinity-gradient energy harvesting.

Keywords

2D clay nanofluidic membranes / ion selectivity / life cycle assessments / natural clay nanofluidic membranes / salinity-gradient cell

References

[1] Z. Zhang, L. Wen, and L. Jiang, “Nanofluidics for Osmotic Energy Conversion,” Nature Reviews Materials 6 (2021): 622–639.

[2] A. Siria, M.-L. Bocquet, and L. Bocquet, “New Avenues for the Large-Scale Harvesting of Blue Energy,” Nature Reviews Chemistry 1 (2017): 0091.

[3] Y. Mei and C. Y. Tang, “Recent Developments and Future Perspectives of Reverse Electrodialysis Technology: A Review,” Desalination 425 (2018): 156–174.

[4] Z. Jia, B. Wang, S. Song, and Y. Fan, “Blue Energy: Current Technologies for Sustainable Power Generation From Water Salinity Gradient,” Renewable and Sustainable Energy Reviews 31 (2014): 91–100.

[5] B. E. Logan and M. Elimelech, “Membrane-Based Processes for Sustainable Power Generation Using Water,” Nature 488 (2012): 313–319.

[6] K. Xiao, L. Jiang, and M. Antonietti, “Ion Transport in Nanofluidic Devices for Energy Harvesting,” Joule 3 (2019): 2364–2380.

[7] Y. Wu, L. Jiang, and L. Wen, “Nanofluidic Membrane for Confined Ion Transport: From Uniform to Composite Strategy,” Materials Today 65 (2023): 189–206.

[8] W. Zhao, Y. Wang, M. Han, J. Xu, L. Han, and K. C. Tam, “Osmotic Energy Generation With Mechanically Robust and Oppositely Charged Cellulose Nanocrystal Intercalating GO Membranes,” Nano Energy 98 (2022): 107291.

[9] L. Bocquet, “Nanofluidics Coming of Age,” Nature Materials 19 (2020): 254–256.

[10] G. Xie, L. Wen, and L. Jiang, “Biomimetic Smart Nanochannels for Power Harvesting,” Nano Research 9 (2016): 59–71.

[11] A. R. Koltonow and J. Huang, “Two-Dimensional Nanofluidics,” Science 351 (2016): 1395–1396.

[12] W. Xin, L. Jiang, and L. Wen, “Two-Dimensional Nanofluidic Membranes Toward Harvesting Salinity Gradient Power,” Accounts of Chemical Research 54 (2021): 4154–4165.

[13] J. Gao, Y. Feng, W. Guo, and L. Jiang, “Nanofluidics in Two-Dimensional Layered Materials: Inspirations From Nature,” Chemical Society Reviews 46 (2017): 5400–5424.

[14] G. Liu, W. Jin, and N. Xu, “Two-Dimensional-Material Membranes: A New Family of High-Performance Separation Membranes,” Angewandte Chemie International Edition 55 (2016): 13384–13397.

[15] J. Ji, Q. Kang, Y. Zhou, et al., “Osmotic Power Generation With Positively and Negatively Charged 2D Nanofluidic Membrane Pairs,” Advanced Functional Materials 27 (2017): 1603623.

[16] F. Hashemifar and A. Esfandiar, “Oppositely Charged MXene Fibers as a Highly Efficient Osmotic Power Generator From Sea and River Water,” Journal of Materials Chemistry A 10 (2022): 24915–24926.

[17] L. Ding, D. Xiao, Z. Lu, et al., “Oppositely Charged Ti₃C₂T_x MXene Membranes With 2D Nanofluidic Channels for Osmotic Energy Harvesting,” Angewandte Chemie International Edition 132 (2020): 8798–8804.

[18] L. Xie, J. Tang, R. Qin, et al., “Surface Charge Modification on 2D Nanofluidic Membrane for Regulating Ion Transport,” Advanced Functional Materials 33 (2023): 2208959.

[19] J. Tang, Y. Wang, H. Yang, et al., “All-Natural 2D Nanofluidics as Highly-Efficient Osmotic Energy Generators,” Nature Communications 15 (2024): 3649.

[20] Y. Zhou, A. M. LaChance, A. T. Smith, H. Cheng, Q. Liu, and L. Sun, “Strategic Design of Clay-Based Multifunctional Materials: From Natural Minerals to Nanostructured Membranes,” Advanced Functional Materials 29 (2019): 1807611.

[21] M. F. Brigatti, E. Galan, and B. Theng, “Structure and Mineralogy of Clay Minerals.” Developments in Clay Science 5 (2013): 21–81.

[22] Y. Liu, J. Ping, and Y. Ying, “Anion-Selective Layered Double Hydroxide Composites-Based Osmotic Energy Conversion for Real-Time Nutrient Solution Detection,” Advanced Science 9 (2022): 2103696.

[23] M. Zhang, N. Sheng, Q. Song, et al., “Enhanced Selective Ion Transport by Assembling Nanofibers to Membrane Pairs With Channel-Like Nanopores for Osmotic Energy Harvesting,” Nano Energy 103 (2022): 107786.

[24] T. J. Konch, T. Dutta, A. B. Neog, R. Gogoi, and K. Raidongia, “Uphill Anion Pumping Through Triangular Nanofluidic Device of Reconstructed Layered Double Hydroxide,” Journal of Physical Chemistry C 125 (2021): 17939–17949.

[25] S. Qin, G. Yang, S. Wang, et al., “Tunable Surface Charge of Layered Double Hydroxide Membranes Enabling Osmotic Energy Harvesting From Anion Transport,” Small 20 (2024): 2400850.

[26] C. Wu, T. Xiao, J. Tang, et al., “Biomimetic Temperature-Gated 2D Cationic Nanochannels for Controllable Osmotic Power Harvesting,” Nano Energy 76 (2020): 105113.

[27] R. Qin, J. Tang, C. Wu, et al., “Nanofiber-Reinforced Clay-Based 2D Nanofluidics for Highly Efficient Osmotic Energy Harvesting,” Nano Energy 100 (2022): 107526.

[28] J.-J. Shao, K. Raidongia, A. R. Koltonow, and J. Huang, “Self-Assembled Two-Dimensional Nanofluidic Proton Channels With High Thermal Stability,” Nature Communications 6 (2015): 7602.

[29] J. Wang, Z. Cui, S. Li, et al., “Unlocking Osmotic Energy Harvesting Potential in Challenging Real-World Hypersaline Environments Through Vermiculite-Based Hetero-Nanochannels,” Nature Communications 15 (2024): 608.

[30] Y. Wu, T. Zhou, Y. Wang, et al., “The Synergistic Effect of Space and Surface Charge on Nanoconfined Ion Transport and Nanofluidic Energy Harvesting,” Nano Energy 92 (2022): 106709.

[31] E. Tombácz and M. Szekeres, “Colloidal Behavior of Aqueous Montmorillonite Suspensions: The Specific Role of pH in the Presence of Indifferent Electrolytes,” Applied Clay Science 27 (2004): 75–94.

[32] Z. Liu, R. Ma, M. Osada, et al., “Synthesis, Anion Exchange, and Delamination of Co−Al Layered Double Hydroxide: Assembly of the Exfoliated Nanosheet/Polyanion Composite Films and Magneto-Optical Studies,” Journal of the American Chemical Society 128 (2006): 4872–4880.

[33] L. Xie, S. Wang, J. Tang, et al., “Clay-Based Anion-Selective 2D Nanofluidics Boost Natural Osmotic Power Generation,” Journal of Materials Chemistry A 13 (2025): 3872–3881.

[34] S. Kaufhold and R. Dohrmann, “The Variable Charge of Dioctahedral Smectites,” Journal of Colloid and Interface Science 390 (2013): 225–233.

[35] X. Xu, J. Wang, A. Zhou, et al., “High-Efficiency CO₂ Separation Using Hybrid LDH-Polymer Membranes,” Nature Communications 12 (2021): 3069.

[36] J. Zhu, X. Liu, M. L. Geier, et al., “Layer-by-Layer Assembled 2D Montmorillonite Dielectrics for Solution-Processed Electronics,” Advanced Materials 28 (2016): 63–68.

[37] Z. Zhang, S. Yang, P. Zhang, J. Zhang, G. Chen, and X. Feng, “Mechanically Strong MXene/Kevlar Nanofiber Composite Membranes as High-Performance Nanofluidic Osmotic Power Generators,” Nature Communications 10 (2019): 2920.

[38] W. Xin, Z. Zhang, X. Huang, et al., “High-Performance Silk-Based Hybrid Membranes Employed for Osmotic Energy Conversion,” Nature Communications 10 (2019): 3876.

[39] Q. Zhu, Y. Li, Q. Qian, et al., ““A Sulfonated Ultramicroporous Membrane With Selective Ion Transport Enables Osmotic Energy Extraction From Multiform Salt Solutions With Exceptional Efficiency,” Energy & Environmental Science 15 (2022): 4148–4156.

[40] Z. Zhang, P. Bhauriyal, H. Sahabudeen, et al., “Cation-Selective Two-Dimensional Polyimine Membranes for High-Performance Osmotic Energy Conversion,” Nature Communications 13 (2022): 3935.

[41] Y. Qian, D. Liu, G. Yang, et al., “Boosting Osmotic Energy Conversion of Graphene Oxide Membranes via Self-Exfoliation Behavior in Nano-Confinement Spaces,” Journal of the American Chemical Society 144 (2022): 13764–13772.

[42] X. Zhu, J. Hao, B. Bao, et al., “Unique Ion Rectification in Hypersaline Environment: A High-Performance and Sustainable Power Generator System,” Science Advances 4 (2018): eaau1665.

[43] X. He, W. Xin, C. Yang, et al., “Two-Dimensional Molybdenum Disulfide/Graphene Oxide Composite Membrane for Stable Osmotic Energy Conversion,” Journal of Membrane Science 732 (2025): 124251.

[44] T. Liu, S. Huang, W. Xin, et al., “High-Performance Graphene Oxide/Sodium Alginate Composite Membrane for Marine Osmotic Energy Conversion,” Journal of Membrane Science 724 (2025): 123987.

[45] T. Zhou, T. Liu, S. Huang, et al., “The Influence of Divalent Ions on the Osmotic Energy Conversion Performance of 2D Cation Exchange Membrane in Reverse Electrodialysis Process,” Desalination 591 (2024): 118036.

[46] Z. Wu, P. Ji, B. Wang, et al., “Oppositely Charged Aligned Bacterial Cellulose Biofilm With Nanofluidic Channels for Osmotic Energy Harvesting,” Nano Energy 80 (2021): 105554.

[47] M. A. Khan, A. R. Safira, and M. Kaseem, “Modulating Chelation With pH Sensitivity for Controlled Structural Defects and Enhanced Electrochemical and Photocatalytic Activities of LDH Films,” Journal of Materials Chemistry A 12 (2024): 3411–3433.

[48] K. Chen, X. Tang, B. Jia, et al., “Graphene Oxide Bulk Material Reinforced by Heterophase Platelets With Multiscale Interface Crosslinking,” Nature Materials 21 (2022): 1121–1129.

[49] K. R. G. Lim, M. Shekhirev, B. C. Wyatt, B. Anasori, Y. Gogotsi, and Z. W. Seh, “Fundamentals of MXene Synthesis,” Nature Synthesis 1 (2022): 601–614.

[50] M. Dadashi Firouzjaei, S. K. Nemani, M. Sadrzadeh, E. K. Wujcik, M. Elliott, and B. Anasori, “Life-Cycle Assessment of Ti₃C₂T_x MXene Synthesis,” Advanced Materials 35 (2023): 2300422.

RIGHTS & PERMISSIONS

2025 The Authors. Carbon Neutralization published by Wenzhou University and John Wiley & Sons Australia, Ltd.