Freshwater scarcity is one of the key challenges facing global sustainable development. Solar-driven interfacial evaporation uses clean, low-cost solar energy to generate localized heating at the water-air interface, offering potential for seawater desalination, wastewater purification, and distributed water supply. In recent years, two-dimensional photothermal fabrics and membrane materials have attracted attention because they are lightweight, flexible, and easy to process. However, during practical outdoor operations, they still face issues such as coating delamination, cracking after repeated bending, insufficient mechanical strength, and difficulty in effectively localizing heat, which restrict their long-term stable application.
To address these bottlenecks, the team from the College of Chemistry and Chemical Engineering of Shaanxi University of Science and Technology and Functional Inorganic Materials Energy Conversion Laboratory started from "yarn" as a continuously processable and weave-integrable material unit. They designed a dynamic electrostatic cladding-spinning strategy that integrates a high-strength mechanical skeleton, a photothermal conversion shell, and thermoelectric waste-heat recovery into a single yarn platform.
Research Highlights
The PM-series core-shell photothermal yarns developed in this study use high-modulus stainless-steel wire as the load-bearing core and a polymer shell containing carbon-based photothermal components as the outer layer. Through dual-channel injection, high-speed rotational cladding, and continuous winding, the photothermal outer layer is uniformly and densely anchored onto the metal core, forming a stable core-shell heterostructure. The hierarchical micro-/nanostructure on the yarn surface extends the propagation and scattering paths of light within the material, thereby enhancing broadband absorption. Meanwhile, the crosslinked interpenetrating network provides continuous pathways for stress transfer, structural stability, and electron transport.
The PM-1.35 photothermal yarn combines high mechanical strength with excellent photothermal performance. A single yarn reaches a maximum tensile strength of 3692 MPa, can be knotted and used to bear weight, and remains structurally intact after repeated folding at liquid-nitrogen temperature, demonstrating outstanding resistance to embrittlement and crack propagation. Under 1 sun irradiation, PM-1.35 reaches a stable photothermal temperature of 78.4 °C. When used for solar-driven interfacial evaporation, it achieves an evaporation rate of 2.18 kg m-2 h-1 and an evaporation efficiency of 89.6%. After 40 consecutive cycling tests, the evaporation rate remains at 2.19 ± 0.05 kg m-2 h-1, confirming good long-term operational stability.
More importantly, the team further integrated the photothermal yarns with commercial thermoelectric modules, converting low-grade waste heat that would otherwise be lost during evaporation into electrical energy. In thermoelectric tests, the system reached a maximum open-circuit voltage of 150.3 mV. Under 1 sun evaporation-cogeneration conditions, the PM-1.35 device stably outputs 40.3 ± 0.6 mV and 4.83 ± 0.24 mA, realizing synergistic clean-water production and thermoelectric power generation.
This work is not simply about increasing the surface temperature of photothermal material. Instead, it couples yarn architecture, mechanical reliability, interfacial evaporation, and waste-heat recovery within one material system. This continuously manufacturable core-shell photothermal yarn is expected to provide a weavable and integrable platform for outdoor desalination, distributed water supply, and low-grade thermal-energy utilization.
Research Group or Author Profile
This study was completed by the College of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, and the Functional Inorganic Materials Energy Conversion Laboratory. The team focuses on the design and synthesis of hybrid azolate frameworks, solar-driven interfacial evaporation, and water-electricity cogeneration devices. It is committed to developing high-performance functional materials and integrated systems for clean-water acquisition, solar-energy utilization, and low-grade heat recovery.
The paper, titled "Dynamic electrostatic cladding spun core- shell photothermal yarns for sustainable solar-driven water-electricity cogeneration," was published in Nano Research on July 16, 2026. Kaiping Tian and Bokun Wang are co-first authors; Bokun Wang, Guiqiang Fei, and Wenhuan Huang are corresponding authors. This work provides a new technical route for the design of high-strength, long-life, multifunctionally integrated photothermal evaporation devices.
This work was supported by the National Key R&D Program of China, the National Natural Science Foundation of China, the Shaanxi Science Fund for Distinguished Young Scholars, the Key Research and Development Program of Shaanxi Province, the Natural Science Basic Research Program of Shaanxi Province, the Key Laboratory Project of the Shaanxi Provincial Department of Education, and the Xi'an Science and Technology Plan Project.
DOI Link:
https://doi.org/10.26599/NR.2026.94908937
About Nano Research
Nano Research is a peer-reviewed, open access, international and interdisciplinary research journal, sponsored by Tsinghua University and the Chinese Chemical Society, published by Tsinghua University Press on the platform SciOpen. It publishes original high-quality research and significant review articles on all aspects of nanoscience and nanotechnology, ranging from basic aspects of the science of nanoscale materials to practical applications of such materials. After 18 years of development, it has become one of the most influential academic journals in the nano field. Nano Research has published more than 1,000 papers every year from 2022, with its cumulative count surpassing 8,000 articles. In 2025 InCites Journal Citation Reports, its 2025 IF is 9.4 (8.3, 5 years), and it continues to be the Q1 area among the four subject classifications. Nano Research Award, established by Nano Research together with TUP and Springer Nature in 2013, and Nano Research Young Innovators (NR45) Awards, established by Nano Research in 2018, have become international academic awards with global influence.
