Issue

Vol. 18 (2026)

Carbon Dots Intercalated MXene for Flexible Organic Hydrogel Absorbers with Synergistically Enhanced Dielectric Loss

https://doi.org/10.1007/s40820-026-02135-6
Bokai Lu
State Key Laboratory of Solidification Processing, Center of Advanced Lubrication and Seal Materials, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, People’s Republic of China
Guangkai Jin
State Key Laboratory of Solidification Processing, Center of Advanced Lubrication and Seal Materials, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, People’s Republic of China
Yuhong Cui
State Key Laboratory of Solidification Processing, Center of Advanced Lubrication and Seal Materials, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, People’s Republic of China
Tianyi Zhang
State Key Laboratory of Solidification Processing, Center of Advanced Lubrication and Seal Materials, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, People’s Republic of China
Shujuan Liu
State Key Laboratory of Solidification Processing, Center of Advanced Lubrication and Seal Materials, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, People’s Republic of China
Qian Ye
State Key Laboratory of Solidification Processing, Center of Advanced Lubrication and Seal Materials, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, People’s Republic of China
Xuqing Liu
State Key Laboratory of Solidification Processing, Center of Advanced Lubrication and Seal Materials, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, People’s Republic of China
Feng Zhou
State Key Laboratory of Solidification Processing, Center of Advanced Lubrication and Seal Materials, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, People’s Republic of China

Corresponding Author: Xuqing Liu

xqliu@nwpu.edu.cn

Nano-Micro Letters, Vol. 18 (2026), Article Number: 302

Abstract

With the rapid development of flexible electronics and wearable devices, there is an increasing demand for absorbing materials that exhibit high electromagnetic wave absorption efficiency and mechanical flexibility. In this work, we present a novel and effective strategy for fabricating flexible microwave absorbers via synergistically integrating a polymer framework with conductive fillers. Carbon dots (CDs) functionalized with catechol groups were first synthesized via a bottom-up approach using directed ultrasonication, employing tannic acid dispersed in acetone as the precursor. Owing to the abundant surface functional groups, the as-prepared CDs were uniformly anchored onto MXene nanosheets through chemical bonding, forming a well-dispersed MXene/CDs composite. Subsequently, this hybrid filler was incorporated into a polymer network composed of polyvinyl alcohol (PVA) and acrylamide, with water and glycerol as co-solvents, to fabricate a flexible MXene/CDs organic hydrogel. Notably, glycerol plays an important role in adjusting the polarity of the gel system, thereby effectively optimizing impedance matching. Meanwhile, the abundant heterogeneous interfaces between MXene and CDs significantly enhanced interfacial polarization, and the synergistic coupling of optimized impedance matching with strong dielectric loss endowed the MXene/CDs organic hydrogel with outstanding electromagnetic wave absorption performance. The absorber achieves a minimum reflection loss (RLmin) of − 47.9 dB at 9.46 GHz with a matching thickness of 3.1 mm, along with an effective absorption bandwidth of 3.5 GHz. Furthermore, the synergistic reinforcement of dual-crosslinked polymer chains and the MXene/CDs filler endowed the hydrogel with excellent mechanical robustness, making it suitable for flexible and wearable absorption applications.


Highlights:
1 Catechol-functionalized carbon dots chemically anchor onto MXene nanosheets, enhancing interfacial polarization and enabling impedance matching optimization through glycerol-regulated gel polarity.
2 A flexible organic hydrogel absorber was constructed via synergistic integration of a dual-crosslinked polymer network and conductive MXene/carbon dots (CDs) hybrid fillers.
3 The MXene/CDs hydrogel exhibits outstanding performance (RLmin= −47.9 dB, 3.5 GHz bandwidth at 3.1 mm) together with improved mechanical robustness.

Keywords

Carbon dots MXene Organic hydrogel Microwave absorber
Lu, Bokai, Guangkai Jin, Yuhong Cui, Tianyi Zhang, Shujuan Liu, Qian Ye, Xuqing Liu, and Feng Zhou. 2026. “Carbon Dots Intercalated MXene for Flexible Organic Hydrogel Absorbers With Synergistically Enhanced Dielectric Loss”. Nano-Micro Letters 18 (March):302. https://doi.org/10.1007/s40820-026-02135-6.
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References
  1. H. Liang, S. Hui, L. Zhang, K. Tao, Q. Chen et al., High-density dual atoms pairs coupling for efficient electromagnetic wave absorbers. Small 21(3), e2408396 (2025). https://doi.org/10.1002/smll.202408396
  2. G. Liu, P. Zhu, J. Teng, R. Xi, X. Wang et al., Optimizing MOF-derived electromagnetic wave absorbers through gradient pore regulation for Pareto improvement. Adv. Funct. Mater. 35(18), 2413048 (2025). https://doi.org/10.1002/adfm.202413048
  3. Y. Ma, Y. Lin, Y. Liu, Y. Cheng, Y. Ma et al., Sugar-gourd-like Co@carbon nanofibers for ultralightweight and outstanding electromagnetic wave absorber. J. Energy Chem. 113, 146–154 (2026). https://doi.org/10.1016/j.jechem.2025.09.032
  4. Y. Cui, F. Wu, J. Wang, Y. Wang, T. Shah et al., Three dimensional porous MXene/CNTs microspheres: Preparation, characterization and microwave absorbing properties. Compos. Part A Appl. Sci. Manuf. 145, 106378 (2021). https://doi.org/10.1016/j.compositesa.2021.106378
  5. Z. Wei, X. Chen, D. Chen, J. Liang, Z. Liao et al., N and S dual doping and defect engineering to modulate electronic structure of 3D honeycomb-like carbon for boosting microwave absorption. Carbon 233, 119925 (2025). https://doi.org/10.1016/j.carbon.2024.119925
  6. G. Wu, Y. Han, D. Lan, S. Zhang, Z. Gao et al., Polyaniline decorative MnCo2O4.5 microspheres coupled with CoNi layered double hydroxides with remarkable electromagnetic wave absorption capacity. Carbon 244, 120631 (2025). https://doi.org/10.1016/j.carbon.2025.120631
  7. D. Mandal, B. Bhandari, S.V. Mullurkara, P.R. Ohodnicki, All-around electromagnetic wave absorber based on Ni-Zn ferrite. ACS Appl. Mater. Interfaces 16(26), 33846–33854 (2024). https://doi.org/10.1021/acsami.4c06498
  8. S. Dong, X. Zhang, P. Hu, W. Zhang, J. Han et al., Biomass-derived carbon and polypyrrole addition on SiC whiskers for enhancement of electromagnetic wave absorption. Chem. Eng. J. 359, 882–893 (2019). https://doi.org/10.1016/j.cej.2018.11.101
  9. D.D. Lim, S. Lee, J.-H. Lee, W. Choi, G.X. Gu, Mechanical metamaterials as broadband electromagnetic wave absorbers: investigating relationships between geometrical parameters and electromagnetic response. Mater. Horiz. 11(10), 2506–2516 (2024). https://doi.org/10.1039/D3MH01959D
  10. P. Chen, S. He, Z. Zou, T. Wang, J. Hu et al., Intelligent hydrogels enabled large-scale variability in continuously tunable microwave absorption. Adv. Funct. Mater. 35(39), 2506308 (2025). https://doi.org/10.1002/adfm.202506308
  11. Y. Tang, X. Wang, Y. Xin, X. Ren, H. Yuan et al., Multi-functional electromagnetic wave absorption hydrogel with adjustable absorption frequency. Carbon 238, 120238 (2025). https://doi.org/10.1016/j.carbon.2025.120238
  12. Z. Zhao, L. Zhang, H. Wu, Hydro/organo/ionogels: “controllable” electromagnetic wave absorbers. Adv. Mater. 34(43), 2205376 (2022). https://doi.org/10.1002/adma.202205376
  13. Y. Wang, C. Zhao, Y. Tian, Y. Sun, M. Zhang et al., Lightweight MXene composite films with hollow egg-box structures: enhanced electromagnetic shielding performance beyond pure MXene. Adv. Sci. 12(10), 2411932 (2025). https://doi.org/10.1002/advs.202411932
  14. C. Li, S. Guo, G. Shi, J. Wang, D. Wang et al., Gas-phase chlorohydrocarbon etching for the synthesis of MXenes. Chem. Eng. J. 519, 165349 (2025). https://doi.org/10.1016/j.cej.2025.165349
  15. H. Shen, H. Zhao, L. Yan, J. Xu, L. Li et al., Photothermal processing of crumpled Ti3C2Tx MXenes with nitrogen/sulfur co-modification for boosting capacitance performance. Carbon 234, 120021 (2025). https://doi.org/10.1016/j.carbon.2025.120021
  16. J. Zhang, L. Xia, L. Yang, J. Li, Y. Liu et al., Ti3C2Tx MXene nanobelts with alkali ion intercalation: dual-purpose for enhanced lithium-ion batteries and microwave absorption. Carbon 237, 120148 (2025). https://doi.org/10.1016/j.carbon.2025.120148
  17. G. Jin, S. Xue, R. Zhang, S. Liu, S. Wang et al., Pulsed laser manufactured heteroatom doped carbon dots via heterocyclic aromatic hydrocarbons for improved tribology performance. Small 20(29), 2311876 (2024). https://doi.org/10.1002/smll.202311876
  18. H. Zhang, J. Bai, X. Chen, L. Wang, W. Peng et al., Surface state-based panchromatic luminescent carbon dots. J. Colloid Interface Sci. 678, 77–87 (2025). https://doi.org/10.1016/j.jcis.2024.08.073
  19. S. Narwal, A. Sura, A. Singh, M. Azam, M. Alam et al., In-situ fabrication of N-doped carbon dots on novel blue-emitting Y2TiWO8: Ce3+ nanophosphor for thermal sensing and fingerprint detection applications. Carbon 219, 118768 (2024). https://doi.org/10.1016/j.carbon.2023.118768
  20. X. Zhou, S. Li, H. Xi, P. Zhong, J. Sun et al., Construction of 0D/2D heterojunction in 3D MXene/GQDs hybrid aerogels for enhanced broad electromagnetic wave absorption. J. Alloys Compd. 1016, 179021 (2025). https://doi.org/10.1016/j.jallcom.2025.179021
  21. H. Huo, J. Shen, J. Wan, H. Shi, H. Yang et al., A tough and robust hydrogel constructed through carbon dots induced crystallization domains integrated orientation regulation. Nat. Commun. 16, 6221 (2025). https://doi.org/10.1038/s41467-025-61535-1
  22. J. Jian, S. Wang, Q. Ye, F. Li, G. Su et al., Activating a semiconductor-liquid junction via laser-derived dual interfacial layers for boosted photoelectrochemical water splitting. Adv. Mater. 34(19), e2201140 (2022). https://doi.org/10.1002/adma.202201140
  23. X. Wang, T. Wang, X. Zhang, S. Liu, Q. Ye et al., Fabrication of nanocomposite supramolecular oleogel lubricant incorporating functionalized Ti3C2Tx MXene for enhanced anti-wear and friction reduction. Colloids Surf. A Physicochem. Eng. Aspects 725, 137530 (2025). https://doi.org/10.1016/j.colsurfa.2025.137530
  24. K.P. Marquez, M.A. Judicpa, R.A.J. Malenab, R.M.C.R. Ramos, E. Austria Jr. et al., Chemically tunable Ti3C2Tx MXene surfaces. ACS Appl. Mater. Interfaces 17(10), 15877–15885 (2025). https://doi.org/10.1021/acsami.5c00314
  25. S. Wu, W. Li, Y. Sun, X. Zhang, J. Zhuang et al., Synthesis of dual-emissive carbon dots with a unique solvatochromism phenomenon. J. Colloid Interface Sci. 555, 607–614 (2019). https://doi.org/10.1016/j.jcis.2019.07.089
  26. C.-F. Du, Z. Wang, X. Wang, X. Zhao, J. Gao et al., Probing the lubricative behaviors of a high MXene-content epoxy-based composite under dry sliding. Tribol. Int. 165, 107314 (2022). https://doi.org/10.1016/j.triboint.2021.107314
  27. L. Qu, S. Zhao, Q. Chang, Y. Xie, J. Wang et al., MXene/carbon dot nanocomposites with photothermal/physical synergistic antibacterial capability for wound healing. ACS Appl. Nano Mater. 8(17), 9044–9054 (2025). https://doi.org/10.1021/acsanm.5c01313
  28. Y. Cui, G. Ru, T. Zhang, K. Yang, S. Liu et al., Schottky interface engineering in Ti3C2Tx/ZnS organic hydrogels for high-performance multifunctional flexible absorbers. Adv. Funct. Mater. 35(11), 2417346 (2025). https://doi.org/10.1002/adfm.202417346
  29. X. Liu, B. Zheng, Y. Hua, S. Lu, Z. Nong et al., Ultralight MXene/rGO aerogel frames with component and structure controlled electromagnetic wave absorption by direct ink writing. Carbon 230, 119650 (2024). https://doi.org/10.1016/j.carbon.2024.119650
  30. Q. Tang, S. Yang, G. Liu, S. Chen, A. Guo et al., Dual-sized diamond synergized Ti3C2Tx MXene for vertically aligned structures to enhance thermal conductivity and microwave absorption performance. Compos. Part A Appl. Sci. Manuf. 195, 108953 (2025). https://doi.org/10.1016/j.compositesa.2025.108953
  31. Y. Cui, S. Xue, S. Wang, X. Chen, S. Liu et al., Fabrication of carbon dots intercalated MXene hybrids via laser treatment as oil-based additives for synergistic lubrication. Carbon 205, 373–382 (2023). https://doi.org/10.1016/j.carbon.2023.01.053
  32. Y. Han, Z. Yin, H. Zhuang, Y. Yao, Y. Yu et al., Synergistic effects of photoactivation and photothermal in MXene heterostructures for the enhanced H2S detection capability. Adv. Funct. Mater. 35(50), e09735 (2025). https://doi.org/10.1002/adfm.202509735
  33. L. Xue, Q. Xu, C. Meng, S. Lei, G. Zhang et al., Achieving the ultra-low friction and wear rate of PEEK-PTFE composites by Ti3C2Tx MXene reinforcement. Tribol. Int. 199, 110030 (2024). https://doi.org/10.1016/j.triboint.2024.110030
  34. D.-Q. Cao, K. Tang, G. Yihuo, Y. Jin, Y.-X. Song et al., Extracellular polymeric substance-intercalated MXene membrane for osmotic power generation. Chem. Eng. J. 515, 163879 (2025). https://doi.org/10.1016/j.cej.2025.163879
  35. J. Park, W. Guan, G. Yu, Smart hydrogels for sustainable agriculture. EcoMat 7(4), e70011 (2025). https://doi.org/10.1002/eom2.70011
  36. Q. Zhang, S. He, A. Mei, W. Xia, Y. Cao et al., Negative swelling and mechanical self-enhancement TAFe@PVA photothermal hydrogel mediated via semi-crystallization for medical implants. Adv. Funct. Mater. 35(24), 2423048 (2025). https://doi.org/10.1002/adfm.202423048
  37. Z. Wang, J. Jiang, K. Wei, X. Zhou, M.W. Shahzad et al., Advanced cellulose-based gels for wearable physiological monitoring: from fiber modification to application optimization. Adv. Funct. Mater. 36(2), e15132 (2026). https://doi.org/10.1002/adfm.202515132
  38. F. Li, N. Wu, H. Kimura, Y. Wang, B.B. Xu et al., Initiating binary metal oxides microcubes electrsomagnetic wave absorber toward ultrabroad absorption bandwidth through interfacial and defects modulation. Nano-Micro Lett. 15(1), 220 (2023). https://doi.org/10.1007/s40820-023-01197-0
  39. D. Zhang, H. Wang, J. Cheng, C. Han, X. Yang et al., Conductive WS2-NS/CNTs hybrids based 3D ultra-thin mesh electromagnetic wave absorbers with excellent absorption performance. Appl. Surf. Sci. 528, 147052 (2020). https://doi.org/10.1016/j.apsusc.2020.147052
  40. N. Zhang, Y. Huang, M. Wang, Synthesis of graphene/thorns-like polyaniline/α-Fe2O3@SiO2 nanocomposites for lightweight and highly efficient electromagnetic wave absorber. J. Colloid Interface Sci. 530, 212–222 (2018). https://doi.org/10.1016/j.jcis.2018.06.088
  41. T. Li, J. Li, D. Zhi, J. Li, W. Deng et al., Top-level electromagnetic design of multishell resonant cavity for microspherical microwave structural absorbers. Small Struct. 6(8), 2400666 (2025). https://doi.org/10.1002/sstr.202400666
  42. Y. Ma, H. Zhao, N. Luo, F. Chen, Q. Fu, From magnetoelectric core-shell structure to compound eye-inspired metamaterials: multiscale design of ultra-wideband electromagnetic wave absorber device. Small 21(24), e2502186 (2025). https://doi.org/10.1002/smll.202502186
  43. Z. Zhu, L. Zhang, P. Liu, C. Liu, J. Ai et al., MOF-derived multicore-shell Fe3O4@Fe@C composite: an ultrastrong electromagnetic wave absorber. Carbon 215, 118477 (2023). https://doi.org/10.1016/j.carbon.2023.118477
  44. F. Gan, Q. Rao, J. Deng, L. Cheng, Y. Zhong et al., Controllable architecture of ZnO/FeNi composites derived from trimetallic ZnFeNi layered double hydroxides for high-performance electromagnetic wave absorbers. Small 19(27), 2300257 (2023). https://doi.org/10.1002/smll.202300257
  45. S. Zhang, Y. Huang, J. Wang, X. Han, G. Zhang et al., Cu1.5Mn1.5O4 hollow sphere decorated Ti3C2Tx MXene for flexible all-solid-state supercapacitor and electromagnetic wave absorber. Carbon 209, 118006 (2023). https://doi.org/10.1016/j.carbon.2023.118006
  46. Y. Lei, J. Tao, J. Zhou, Z. Yao, P. Liu et al., Anion activation engineering for stimulating the dielectric response of MXene electromagnetic wave absorbers. J. Mater. Sci. Technol. 256, 310–320 (2026). https://doi.org/10.1016/j.jmst.2025.06.057
  47. R. Zhang, B. Yuan, F. Pan, H. Liang, H. Jiang et al., Ultratransparent, stretchable, and durable electromagnetic wave absorbers. Matter 8(3), 101956 (2025). https://doi.org/10.1016/j.matt.2024.101956
  48. L. Yu, Q. Zhu, Z. Guo, Y. Cheng, Z. Jia et al., Unique electromagnetic wave absorber for three-dimensional framework engineering with copious heterostructures. J. Mater. Sci. Technol. 170, 129–139 (2024). https://doi.org/10.1016/j.jmst.2023.06.024
  49. C. Zhang, H. Zhao, T. Zhou, B. Guo, S. Huang et al., Ni Co -C/polyacrylamide hydrogels derived from mixed metal MOF-74 for synergistically enhanced electromagnetic wave absorption and thermal conduction performances. Chem. Eng. J. 505, 159506 (2025). https://doi.org/10.1016/j.cej.2025.159506
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