Chemical Research in Chinese Universities ›› 2025, Vol. 41 ›› Issue (3): 564-572.doi: 10.1007/s40242-025-4253-3

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Room Temperature Mo2CTx MXene Sensor for Selective Detection of ppb-Level H2S

LI Ouhang1, WANG Bo1, LIU Yong1, GAO Xinxin3, ZHANG Kan3, SUN Peng1,2, LIU Fangmeng1, LU Geyu1,2   

  1. 1. State Key Laboratory of Integrated Optoelectronics, JLU Region, Key Laboratory of Advanced Gas Sensors, Jilin Province, College of Electronic Science and Engineering, Jilin University, Changchun 130012, P. R. China;
    2. International Center of Future Science, Jilin University, Changchun 130012, P. R. China;
    3. Department of Materials Science and Key Laboratory of Automobile Materials of Ministry of Education, State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, P. R. China
  • Received:2024-12-25 Revised:2025-02-06 Online:2025-06-01 Published:2025-05-27
  • Contact: LIU Fangmeng,E-mail:liufangmeng@jlu.edu.cn E-mail:liufangmeng@jlu.edu.cn
  • Supported by:
    This work was supported by the National Key Research and Development Program of China (No. 2021YFB3201300), the National Natural Science Foundation of China (Nos. 62122030 and 62333008), the Application and Basic Research Program of Jilin Province, China (No. 20130102010-JC), and the Jilin Provincial Science and Technology Development Program, China (No. 20230101072JC).

Abstract: The sensitive and selective detection of ppb-level (ppb: parts per billion) H2S using miniaturized and portable gas sensor is of great significance in environmental monitoring, medical diagnosis and many other fields. MXenes, with high electrical conductivity, large surface area, and abundant active sites, hold great promise for room temperature gas sensing applications. In this work, a room temperature H2S sensor was constructed utilizing Mo2CTx MXene sensitive material, synthesized by a typical LiF/HCl etching method. The H2S sensing characteristics of Mo2CTx sensor were further improved by controlling ultrasonic time and optimizing heat-treated temperature. The M-50 sensor utilizing optimized Mo2CTx sensing material exhibited good selectivity, the highest response value (-39.92%) to 1 ppm (ppm: parts per million) H2S, and the lowest detection limit of 30 ppb (theoretically 0.35 ppb). The enhanced H2S sensing properties are largely attributed to the fragmented nanosheet structure and surface defects caused by prolonging ultrasonic time and adjusting treatment temperature. Additionally, density functional theory (DFT) calculations demonstrated that surface Mo atom vacancy and edge of Mo2CTx could significantly improve the adsorption ability of H2S. The present work contributes to advancing exploration of Mo2CTx material in sensing applications.

Key words: Room temperature H2S sensor, Mo2CTx MXene, Ultrasound, Vacuum heat treatment, Density functional theory (DFT) calculation