Chen Winston Yenyu, Sullivan Connor Daniel, Lai Sz-Nian, Yen Chao-Chun, Jiang Xiaofan, Peroulis Dimitrios, Stanciu Lia A
School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907, United States.
Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States.
ACS Omega. 2022 Aug 10;7(33):29195-29203. doi: 10.1021/acsomega.2c03272. eCollection 2022 Aug 23.
Two-dimensional transition-metal carbides and nitrides (MXenes) have been regarded as promising sensing materials because of their high surface-to-volume ratios and outstanding electronic, optical, and mechanical properties with versatile transition-metal and surface chemistries. However, weak gas-molecule adsorption of MXenes poses a serious limitation to their sensitivity and selectivity, particularly for trace amounts of volatile organic compounds (VOCs) at room temperature. To deal with these issues, Au-decorated MXenes are synthesized by a facile solution mixing method for room-temperature sensing of a wide variety of oxygen-based and hydrocarbon-based VOCs. Dynamic sensing experiments reveal that optimal decoration of Au nanoparticles (NPs) on TiCT MXene significantly elevates the response and selectivity of the flexible sensors, especially in detecting formaldehyde. Au-TiCT gas sensors exhibited an extremely low limit of detection of 92 ppb for formaldehyde at room temperature. Au-TiCT provides reliable gas response, low noise level, ultrahigh signal-to-noise ratio, high selectivity, as well as parts per billion level of formaldehyde detection. The prominent mechanism for Au-TiCT in sensing formaldehyde is elucidated theoretically from density functional theory simulations. The results presented here strongly suggest that decorating noble-metal NPs on MXenes is a feasible strategy for the development of next-generation ultrasensitive sensors for Internet of Things.
二维过渡金属碳化物和氮化物（MXenes）因其高的表面体积比以及具有多种过渡金属和表面化学性质的出色电子、光学和机械性能，而被视为有前景的传感材料。然而，MXenes对气体分子的吸附较弱，这严重限制了它们的灵敏度和选择性，尤其是在室温下对痕量挥发性有机化合物（VOCs）的检测。为了解决这些问题，通过一种简便的溶液混合方法合成了金修饰的MXenes，用于对多种基于氧和基于碳氢化合物的VOCs进行室温传感。动态传感实验表明，在TiCT MXene上对金纳米颗粒（NPs）进行最佳修饰可显著提高柔性传感器的响应和选择性，尤其是在检测甲醛方面。Au-TiCT气体传感器在室温下对甲醛的检测限极低，为92 ppb。Au-TiCT具有可靠的气体响应、低噪声水平、超高信噪比、高选择性以及十亿分之一级别的甲醛检测能力。从密度泛函理论模拟出发，从理论上阐明了Au-TiCT传感甲醛的突出机制。此处给出的结果有力地表明，在MXenes上修饰贵金属NPs是开发下一代物联网超灵敏传感器的可行策略。
