MXene/B-doped g-C3N4 for synergistic solar water purification: Coupling interfacial evaporation and photocatalysis

The world faces dual challenges of water scarcity and pollution. Interfacial solar steam generation technology utilizes solar energy to efficiently produce freshwater, offering a sustainable off-grid purification solution. However, it primarily removes non-volatile substances like salts, while its effectiveness against volatile organic pollutants and pathogens remains a key limitation.

The “Green and Functional Polymer Innovation Team” led by Luke Yan from Chang’an University designed and fabricated a multifunctional composite membrane. This novel membrane ingeniously integrates efficient solar-driven water evaporation with simultaneous deep degradation of pollutants. Through meticulous structural design, the team mechanically interlocked two nanomaterials—highly efficient photothermal 2D MXene and boron-doped graphitic carbon nitride nanospheres—to construct a new synergistic "photothermal-photocatalytic" membrane.

The membrane designed by the research team features a structure that forms nanochannels conducive to the rapid transport of water molecules while achieving minimal heat loss. Under one sun irradiation, the membrane surface temperature rapidly rises to approximately 62°C, delivering an evaporation rate as high as 2.10 kg m^-2 h^-1 and an excellent photothermal conversion efficiency of 94.2%. More importantly, a favorable band structure formed between MXene and the modified carbon nitride significantly promotes the separation of photogenerated charges, resulting in a 2.8-fold increase in transient photocurrent response. This activates the material's strong oxidative degradation capability under light. In practical testing using water from a eutrophic lake, the membrane not only stably produced clean freshwater but also achieved comprehensive water quality improvement: total organic carbon (TOC) removal reached 90.0%, chemical oxygen demand (COD) was reduced by 92.0%, total microbial count (TMC) decreased by 93.1%, and it demonstrated a potent sterilization rate exceeding 99% against both E. coli and S. aureus. Luke Yan said: “This research marks a critical step toward multifunctional integration in water purification technology. It simultaneously addresses the dual challenges of 'water scarcity' and 'water pollution' on a single, streamlined platform, providing a scalable and innovative blueprint for developing the next generation of energy-efficient, high-performance, and sustainable distributed water treatment systems.”

Other contributors include Luke Yan, Xi Chen, Xushuai Chen, Panpan Zhang, Ruiqi Zhao, Chunjia Luo and Min Chao from the School of Materials Science and Engineering, Chang’an University, Xi’an, China.

This work was supported by Innovation Capability Support Program of Shaanxi (2023-CX-TD-43), Key Research and Development Program of Shaanxi (2024GX-YBXM-412), Fundamental Research Funds for the Central Universities, CHD (300102313208, 300102314105, 300102314401).

DOI Link:

https://doi.org/10.26599/NR.2026.94908325

About the Authors

Yan Luke (1979 -): male, from Fufeng, Shaanxi Province; Ph. D. of Material Science, Professor; Doctor Tutor; Young Academic Leader of Chang’an University; Visiting Scholar of Leibniz Polymer Research Institute, Dresden, Germany. He is expert in the design, preparation, modification and application of green and functional polymer, separation membranes, traffic functional materials, special engineering plastics and polymer composites, as well as green recycling and high-value utilization of waste plastics. For more information, visit his research homepage: https://js.chd.edu.cn/clkxygcxy/ylk/list.htm.

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.