Dual Convection Driven Humidity Management: A Novel Route to Efficient and Stable Solar Desalination

Abstract

Solar-driven interfacial evaporation has evolved into a sustainable technology with the potential to alleviate the shortage of freshwater resources. Despite remarkable progress in developing photothermal materials, substrates and hybrid configurations, these approaches aimed at improving the evaporation performance appear to have hit a plateau. This limitation can be attributed to the neglect of thermal convection, a critical factor that significantly impacts evaporator performance. Herein, a wood-based evaporator featuring a dual convection structure was developed by creating a central cavity in a wood block and integrating MXene photothermal materials. It is worth highlighting that the evaporator delivers an exceptional evaporation rate of 2.16 kg/(m²·h) and a photothermal conversion efficiency of 118% without necessitating the use of special materials or intricate architectures. Simulations revealed that the purposely designed dual-convection structure effectively regulates the heat distribution and reduces the humidity above the evaporation surface, which proved to greatly enhance both the evaporation rate and the overall photothermal conversion efficiency. Furthermore, the device demonstrates good resistance to saline conditions and long-term operational stability, even under extreme pH conditions. This work provides novel insights into the design of high-efficiency, structurally simplified solar interfacial evaporators and broadens the potential applications of wood-based materials in solar-driven evaporation systems.

Keywords

dual convection structure / MXene / solar-driven interfacial evaporation / surface humidity modulation / wood

References

[1] X. Wu, Y. Lu, X. Ren, et al., “Interfacial Solar Evaporation: From Fundamental Research to Applications,” Advanced Materials 36, no. 23 (2024): 2313090.

[2] D. Macias, B. Bisselink, C. Carmona-Moreno, et al., “The Overlooked Impacts of Freshwater Scarcity on Oceans as Evidenced by the Mediterranean Sea,” Nature Communications 16, no. 1 (2025): 998.

[3] Y. Yang, D. He, X. Feng, and X. Xiao, “Low-Dimension Confinement Effect in COF-Based Hetero-Photocatalyst for Energy-Conversion Application,” SmartMat 5, no. 3 (2024): e1238.

[4] Z. Bai, P. Wang, J. Xu, R. Wang, and T. Li, “Progress and Perspectives of Sorption-Based Atmospheric Water Harvesting for Sustainable Water Generation: Materials, Devices, and Systems,” Science Bulletin 69, no. 5 (2024): 671–687.

[5] L. Hou, S. Li, Y. Qi, et al., “Advancing Efficiency in Solar-Driven Interfacial Evaporation: Strategies and Applications,” ACS Nano 19, no. 10 (2025): 9636–9683.

[6] J. Wang, Y. Kong, Z. Liu, and H. Wang, “Solar-Driven Interfacial Evaporation: Design and Application Progress of Structural Evaporators and Functional Distillers,” Nano Energy 108 (2023): 108115.

[7] Q. Xiong, D. Wang, B. Shao, et al., “Unlocking Zero Liquid Discharge: A Parallel Water Supply Strategy to Realize Selective Salt Crystallization for Long-Term Interfacial Solar Evaporation,” Advanced Functional Materials 35, no. 7 (2025): 2409257.

[8] Y. Dong, Y. Tan, K. Wang, et al., “Reviewing Wood-Based Solar-Driven Interfacial Evaporators for Desalination,” Water Research 223 (2022): 119011.

[9] N. Liu, L. Hao, B. Zhang, R. Niu, J. Gong, and T. Tang, “Rational Design of High-Performance Bilayer Solar Evaporator by Using Waste Polyester-Derived Porous Carbon-Coated Wood,” Energy & Environmental Materials 5, no. 2 (2022): 617–626.

[10] B. Yang, C. Li, Z. Wang, and Q. Dai, “Thermoplasmonics in Solar Energy Conversion: Materials, Nanostructured Designs, and Applications,” Advanced Materials 34, no. 26 (2022): 2107351.

[11] X. Cui, Q. Ruan, X. Zhuo, et al., “Photothermal Nanomaterials: A Powerful Light-To-Heat Converter,” Chemical Reviews 123, no. 11 (2023): 6891–6952.

[12] Y. Zhang, X. Li, W. Xi, et al., “Constructing a Hierarchical MoS₂/MXene Heterostructure for Efficient Capacitive Deionization of Saline Water,” Chemical Synthesis 4, no. 2 (2024): 19.

[13] J. Chang, B. Pang, H. Zhang, K. Pang, M. Zhang, and J. Yuan, “MXene/Cellulose Composite Cloth for Integrated Functions (If-Cloth) in Personal Heating and Steam Generation,” Advanced Fiber Materials 6, no. 1 (2024): 252–263.

[14] Y. Li, Y. Shi, H. Wang, et al., “Recent Advances in Carbon-Based Materials for Solar-Driven Interfacial Photothermal Conversion Water Evaporation: Assemblies, Structures, Applications, and Prospective,” Carbon Energy 5, no. 11 (2023): e331.

[15] X. Ma, R. Su, Z. Zeng, L. Li, H. Wang, and S. Wang, “Wood-Based Solar-Driven Interfacial Evaporators: Design and Application,” Chemical Engineering Journal 471 (2023): 144517.

[16] H. Lu, W. Shi, F. Zhao, et al., “High-Yield and Low-Cost Solar Water Purification via Hydrogel-Based Membrane Distillation,” Advanced Functional Materials 31, no. 19 (2021): 2101036.

[17] J. Chen, M. Lee, Y. Qiu, C. Wu, B. Li, and Y. Yin, “Emulsion-Templated Synthesis of 3D Evaporators for Efficient Solar Steam Generation,” SmartMat 4, no. 2 (2023): 69–77.

[18] J. Li, H. Li, L. Xu, et al., “Biomimetic Nanoporous Aerogels From Branched Aramid Nanofibers Combining High Heat Insulation and Compressive Strength,” SmartMat 2, no. 1 (2021): 76–87.

[19] J. Li, X. Wang, Z. Lin, et al., “Over 10 kg m⁻² h⁻¹ Evaporation Rate Enabled by a 3D Interconnected Porous Carbon Foam,” Joule 4, no. 4 (2020): 928–937.

[20] L. Liu, H. Liu, Z. Fan, et al., “Simultaneous Solar-Driven Interfacial Evaporation and Photo-Fenton Oxidation by Semiconducting Metal–Organic Framework From Waste Polyimide,” Energy & Environmental Materials 8, no. 2 (2024): e12812.

[21] F. Zhao, X. Zhou, Y. Shi, et al., “Highly Efficient Solar Vapour Generation via Hierarchically Nanostructured Gels,” Nature Nanotechnology 13, no. 6 (2018): 489–495.

[22] L. Peng, X. Gu, H. Yang, D. Zheng, P. Wang, and H. Cui, “Ultra-High Evaporation Rate 3D Evaporator With Vertical Sheets Based on Full Use of Convection Flow,” Journal of Cleaner Production 345 (2022): 131172.

[23] X. Zhao, Y. Liu, L. Zhao, et al., “A Scalable High-Porosity Wood for Sound Absorption and Thermal Insulation,” Nature Sustainability 6, no. 3 (2023): 306–315.

[24] Q. Ding, B. Jin, Y. Zheng, et al., “Integration of Bio-Enzyme-Treated Super Wood and AIE-Based Nonwoven Fabric for Efficient Evaporating the Wastewater With High Concentration of Ammonia Nitrogen,” Nano-Micro Letters 17, no. 1 (2025): 176.

[25] Y. Lu, H. Zhang, D. Fan, Z. Chen, and X. Yang, “Coupling Solar-Driven Photothermal Effect Into Photocatalysis for Sustainable Water Treatment,” Journal of Hazardous Materials 423 (2022): 127128.

[26] M. S. Irshad, N. Arshad, M. S. Asghar, et al., “Advances of 2D-Enabled Photothermal Materials in Hybrid Solar-Driven Interfacial Evaporation Systems Toward Water-Fuel-Energy Crisis,” Advanced Functional Materials 33, no. 51 (2023): 2304936.

[27] M. Gao, T. Zhang, and G. W. Ho, “Advances of Photothermal Chemistry in Photocatalysis, Thermocatalysis, and Synergetic Photothermocatalysis for Solar-To-Fuel Generation,” Nano Research 15, no. 12 (2022): 9985–10005.

[28] Y. Lu, D. Fan, Z. Shen, H. Zhang, H. Xu, and X. Yang, “Design and Performance Boost of a MOF-Functionalized-Wood Solar Evaporator Through Tuning the Hydrogen-Bonding Interactions,” Nano Energy 95 (2022): 107016.

[29] W. Li, T. Li, B. Deng, et al., “Fabrication of a Facile Self-Floating Lignin-Based Carbon Janus Evaporators for Efficient and Stable Solar Desalination,” Advanced Composites and Hybrid Materials 7, no. 2 (2024): 52.

[30] Y. Liu, X. Tan, Z. Liu, et al., “Heat-Localized and Salt-Resistant 3D Hierarchical Porous Ceramic Platform for Efficient Solar-Driven Interfacial Evaporation,” Small 20, no. 34 (2024): 2400796.

[31] X. He, C. Cui, Y. Chen, L. Zhang, X. Sheng, and D. Xie, “MXene and Polymer Collision: Sparking the Future of High-Performance Multifunctional Coatings,” Advanced Functional Materials 34, no. 51 (2024): 2409675.

[32] X. Geng, P. Yang, and Y. Wan, “How to Reduce Enthalpy in the Interfacial Solar Water Generation System for Enhancing Efficiency,” Nano Energy 123 (2024): 109434.

[33] H. Zheng, J. Fan, A. Chen, et al., “Enhancing Solar-Driven Water Purification by Multiscale Biomimetic Evaporators Featuring Lamellar MoS₂/GO Heterojunctions,” ACS Nano 18, no. 4 (2024): 3115–3124.

[34] J. Ren, L. Chen, J. Gong, J. Qu, and R. Niu, “Hofmeister Effect Mediated Hydrogel Evaporator for Simultaneous Solar Evaporation and Thermoelectric Power Generation,” Chemical Engineering Journal 458 (2023): 141511.

[35] C. Wang, K. Xu, G. Shi, and D. Wei, “Water Skin Effect and Arched Double-Sided Evaporation for Boosting All-Weather High Salinity Desalination,” Advanced Energy Materials 13, no. 21 (2023): 2300134.

[36] Y. Wang, H. Ma, J. Yu, et al., “All-Dielectric Insulated 3D Plasmonic Nanoparticles for Enhanced Self-Floating Solar Evaporation Under One Sun,” Advanced Optical Materials 11, no. 7 (2023): 2201907.

[37] Y. Zou, C. Qin, H. Zhai, C. Sun, B. Zhang, and X. Wu, “The Optical Characteristics of C@Cu Core-Shell Nanorods for Solar Thermal Applications,” International Journal of Thermal Sciences 182 (2022): 107824.

[38] L. Song, X. F. Zhang, Z. Wang, T. Zheng, and J. Yao, “Fe₃O₄/Polyvinyl Alcohol Decorated Delignified Wood Evaporator for Continuous Solar Steam Generation,” Desalination 507 (2021): 115024.

[39] Z. Yu, S. Cheng, C. Li, Y. Sun, and B. Li, “Enhancing Efficiency of Carbonized Wood Based Solar Steam Generator for Wastewater Treatment by Optimizing the Thickness,” Solar Energy 193 (2019): 434–441.

[40] F. He, M. Han, J. Zhang, et al., “A Simple, Mild and Versatile Method for Preparation of Photothermal Woods Toward Highly Efficient Solar Steam Generation,” Nano Energy 71 (2020): 104650.

[41] H. Jang, J. Choi, H. Lee, and S. Jeon, “Corrugated Wood Fabricated Using Laser-Induced Graphitization for Salt-Resistant Solar Steam Generation,” ACS Applied Materials & Interfaces 12, no. 27 (2020): 30320–30327.

[42] Y. Gu, D. Wang, Y. Gao, et al., “Solar-Powered High-Performance Lignin-Wood Evaporator for Solar Steam Generation,” Advanced Functional Materials 33, no. 43 (2023): 2306947.

[43] K. Goharshadi, S. A. Sajjadi, E. K. Goharshadi, and R. Mehrkhah, “Highly Efficient Plasmonic Wood/Ag/Pd Photoabsorber in Interfacial Solar Steam Generation,” Materials Research Bulletin 154 (2022): 111916.

[44] S. Chen, Z. Sun, W. Xiang, et al., “Plasmonic Wooden Flower for Highly Efficient Solar Vapor Generation,” Nano Energy 76 (2020): 104998.

[45] Y. Pang, C. Ma, L. Song, et al., “Constructing Thermal Convection Film for Low Heat Loss and High Salt Resistance in Wood-Based Solar Evaporators,” Small 20, no. 42 (2024): 2403141.

[46] Y. Pang, X. Chu, L. Song, et al., “Laser-Engraved Wood-Based Evaporators: A Sustainable Approach for Solar Interfacial Evaporation,” Chemical Engineering Journal 479 (2024): 147891.

[47] Y. Li, J. Chen, P. Cai, and Z. Wen, “An Electrochemically Neutralized Energy-Assisted Low-Cost Acid-Alkaline Electrolyzer for Energy-Saving Electrolysis Hydrogen Generation,” Journal of Materials Chemistry A 6, no. 12 (2018): 4948–4954.

[48] Z. Lei, X. Sun, S. Zhu, et al., “Nature Inspired MXene-Decorated 3D Honeycomb-Fabric Architectures Toward Efficient Water Desalination and Salt Harvesting,” Nano-Micro Letters 14, no. 1 (2022): 10.

[49] M. A. Abdelsalam, M. Sajjad, A. Raza, F. Almarzooqi, and T. Zhang, “Sustainable Biomimetic Solar Distillation With Edge Crystallization for Passive Salt Collection and Zero Brine Discharge,” Nature Communications 15, no. 1 (2024): 874.

RIGHTS & PERMISSIONS

2026 The Author(s). SmartMat published by Tianjin University and John Wiley & Sons Australia, Ltd.