Zhang Yalin, Yang Xueli, Sun Zhen, Hu Zheng, Liu Wenlu, Pan Guofeng, Guo Lanlan
School of Electronics and Information Engineering, Hebei University of Technology, Tianjin Key Laboratory of Electronic Materials and Devices, 5340 Xiping Road, Beichen District, Tianjin, 300401, China.
School of Electronics and Information Engineering, Hebei University of Technology, Tianjin Key Laboratory of Electronic Materials and Devices, 5340 Xiping Road, Beichen District, Tianjin, 300401, China; Innovation and Research Institute of Hebei University of Technology in Shijiazhuang, Shijiazhuang, 050299, China.
Anal Chim Acta. 2025 Feb 1;1337:343578. doi: 10.1016/j.aca.2024.343578. Epub 2024 Dec 21.
Trimethylamine (TMA) is a colorless, volatile gas with a strong irritating odor. Prolonged exposure to a certain amount of TMA can cause symptoms such as dizziness, nausea and difficulty breathing, and may even be life-threatening. Therefore, effective detection of TMA is crucial. Gas sensors, due to their convenience, affordability and ability to real-time detect volatile gases including TMA, are increasingly favored. However, gas sensors based on single metal oxide materials have numerous drawbacks and may not meet practical requirements. Therefore, it is necessary to modify gas-sensitive materials to achieve sensors with higher sensitivity and selectivity at lower operating temperatures.
In this research, gas-sensitive materials for detecting TMA were synthesized using liquid-phase methods. Firstly, metal-organic framework-derived ZnO nanoparticles were prepared via a co-precipitation method, followed by the in-situ reduction method to prepare ZnO modified with Au, Pd, and AuPd bimetallic nanoparticles. The experimental results revealed that when the total loading of AuPd was 2 wt% and the ratio was Au:Pd = 1:1, the gas-sensitive performance was enhanced significantly. The AuPd-ZnO sensor exhibited a remarkable high response of 1608.3 to 100 ppm TMA at 200 °C, which was approximately 140 times that of pristine ZnO (R/R = 11.5, 275 °C), and the optimal operating temperature was reduced by 75 °C. Additionally, the sensor boasted a rapid response time (3 s), and low detection limit (50 ppb), high selectivity along with good long-term stability.
The modified material can enable lower power consumption, increased sensitivity and enhanced stability for real-time detection of TMA. Combined with multiple characterization methods, the sensing mechanism of performance improvement was analyzed, which benefited from the electronic and chemical sensitization of Au and Pd, along with the synergistic effect of the AuPd bimetal. This research provided an effective strategy for the design of high-performance TMA gas sensors.
三甲胺（TMA）是一种无色、挥发性气体，具有强烈的刺激性气味。长时间暴露于一定量的TMA会导致头晕、恶心和呼吸困难等症状，甚至可能危及生命。因此，有效检测TMA至关重要。气体传感器因其便利性、经济性以及能够实时检测包括TMA在内的挥发性气体而越来越受到青睐。然而，基于单一金属氧化物材料的气体传感器存在诸多缺点，可能无法满足实际需求。因此，有必要对气敏材料进行改性，以实现能够在较低工作温度下具有更高灵敏度和选择性的传感器。
在本研究中，采用液相法合成了用于检测TMA的气敏材料。首先，通过共沉淀法制备了金属有机框架衍生的ZnO纳米颗粒，然后采用原位还原法制备了用Au、Pd和AuPd双金属纳米颗粒改性的ZnO。实验结果表明，当AuPd的总负载量为2 wt%且比例为Au:Pd = 1:1时，气敏性能显著增强。AuPd-ZnO传感器在200°C下对100 ppm TMA表现出高达1608.3的显著高响应，约为原始ZnO（R/R = 11.5，275°C）的140倍，并且最佳工作温度降低了75°C。此外，该传感器具有快速响应时间（3 s）、低检测限（50 ppb）、高选择性以及良好的长期稳定性。
改性材料能够实现更低的功耗、更高的灵敏度以及增强的稳定性，用于实时检测TMA。结合多种表征方法，分析了性能提升的传感机制，这得益于Au和Pd的电子和化学敏化以及AuPd双金属的协同效应。本研究为高性能TMA气体传感器的设计提供了一种有效策略。
