Issue

Vol. 18 (2026)

Quantitative Defect–Property Correlations in Ti3C2Tx MXenes via Precursor-Controlled Defect Engineering

https://doi.org/10.1007/s40820-026-02106-x
Tufail Hassan
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Seobu‑Ro 2066, Jangan‑Gu, Suwon‑Si, Gyeonggi‑Do 16419, Republic of Korea
Doyeon Lee
Division of Advanced Materials Engineering, College of Engineering, Jeonbuk National University, Jeonju 54896, Republic of Korea
Shabbir Madad Naqvi
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Seobu‑Ro 2066, Jangan‑Gu, Suwon‑Si, Gyeonggi‑Do 16419, Republic of Korea
Myungjae Kim
Hydrogen Technology Research Team, Hyundai‑Steel, Bukbusneop‑ro, Songak‑Eup, Dangjin‑Si, Chungnam 31719, Republic of Korea
Jung‑Min Oh
R&D Center, INNOMXENE Co., Ltd., Daejeon 34365, Republic of Korea
Sang Woon Park
R&D Center, INNOMXENE Co., Ltd., Daejeon 34365, Republic of Korea
Aamir Iqbal
Swiss Federal Laboratories for Materials Science and Technology, Empa, 8600 Dubendorf, Switzerland
Soo Yeong Cho
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Seobu‑Ro 2066, Jangan‑Gu, Suwon‑Si, Gyeonggi‑Do 16419, Republic of Korea
Zhiwang Hao
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Seobu‑Ro 2066, Jangan‑Gu, Suwon‑Si, Gyeonggi‑Do 16419, Republic of Korea
Noushad Hussain
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Seobu‑Ro 2066, Jangan‑Gu, Suwon‑Si, Gyeonggi‑Do 16419, Republic of Korea
Zubair Khalid
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Seobu‑Ro 2066, Jangan‑Gu, Suwon‑Si, Gyeonggi‑Do 16419, Republic of Korea
Shakir Zaman
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Seobu‑Ro 2066, Jangan‑Gu, Suwon‑Si, Gyeonggi‑Do 16419, Republic of Korea
Xiangmeng Kong
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Seobu‑Ro 2066, Jangan‑Gu, Suwon‑Si, Gyeonggi‑Do 16419, Republic of Korea
Ki‑Min Roh
Resources Utilization Research Division, Korea Institute of Geoscience & Mineral Resources, Daejeon 34132, Republic of Korea
Hanjung Kwon
Division of Advanced Materials Engineering, College of Engineering, Jeonbuk National University, Jeonju 54896, Republic of Korea
Chong Min Koo
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Seobu‑Ro 2066, Jangan‑Gu, Suwon‑Si, Gyeonggi‑Do 16419, Republic of Korea

Corresponding Author: Chong Min Koo

chongminkoo@skku.edu

Nano-Micro Letters, Vol. 18 (2026), Article Number: 264

Abstract

Defect engineering holds great promise for tailoring the multifunctional properties of MXenes. However, quantitative correlations between defect and material performance remain largely unexplored due to the lack of a reliable strategy to precisely control defect densities. Here, we demonstrate that the defect density of Ti3C2Tx MXenes—including titanium and carbon vacancies, substitutional oxygen defects, and the associated lattice strain—is precisely controlled by adjusting carbon stoichiometry during TiC precursor synthesis and aluminum content during Ti3AlC2 MAX formation. The defect densities propagate from precursors to final MXenes, enabling the fabrication of a series of Ti3C2Tx MXenes with systematically controlled defect densities. This allows a quantitative correlation between defect density and multifunctional properties including electrical and thermal conductivities, infrared emissivity, electromagnetic shielding effectiveness, Joule heating performance, and oxidation stability. The defect-minimized Ti3C2Tx MXene exhibits outstanding performance, with an electrical conductivity of 26,000 S cm−1, thermal conductivity of 57 W m−1 K−1, electromagnetic shielding effectiveness of 90.5 dB at 10 µm, Joule heating performance of 263 °C at 1.5 V, ultralow infrared emissivity of 0.05, and superior oxidation resistance (activation energy of 72 kJ mol−1). Furthermore, this work establishes a comprehensive quantitative framework linking defect structure to multifunctional performance and stability.


Highlights:
1 Titanium vacancies (VTi), carbon vacancies (VC), and substitutional oxygen (SO) defects were precisely tuned in TiC and Ti3AlC2 MAX phases by adjusting C and Al feed ratios, yielding Ti3C2Tx MXenes with systematically varied defect densities.
2 Defect minimization resulted in excellent multifunctional performance, including electrical conductivity of 26,000 S cm−1, thermal conductivity of 57 W m−1 K−1, infrared emissivity of 0.05, EMI shielding of 90.5 dB (at 10 µm), Joule heating of 263 °C (at 1.5 V), and activation energy of 72 kJ mol−1.
3 The defect-minimized MXene exhibited excellent oxidation stability, retaining ~90% optical absorption after 4 months in dilute dispersion (0.02 mg mL−1).
4 This study establishes a comprehensive quantitative framework linking precursor-derived defect structures to electrical, thermal, optical, and environmental stability of MXenes.

Keywords

MXenes Defect engineering Vacancies and substitutions defects Defect–property correlation Oxidation resistance
Hassan, Tufail, Doyeon Lee, Shabbir Madad Naqvi, Myungjae Kim, Jung‑Min Oh, Sang Woon Park, Aamir Iqbal, Soo Yeong Cho, Zhiwang Hao, Noushad Hussain, Zubair Khalid, Shakir Zaman, Xiangmeng Kong, Ki‑Min Roh, Hanjung Kwon, and Chong Min Koo. 2026. “Quantitative Defect–Property Correlations in Ti3C2Tx MXenes via Precursor-Controlled Defect Engineering”. Nano-Micro Letters 18 (March):264. https://doi.org/10.1007/s40820-026-02106-x.
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