Molybdenum Trioxide (α-MoO3) Nanoribbons for Ultrasensitive Ammonia (NH3) Gas Detection: Integrated Experimental and Density Functional Theory Simulation Studies
Molybdenum Trioxide (α-MoO3) Nanoribbons for Ultrasensitive Ammonia (NH3) Gas Detection: Integrated Experimental and Density Functional Theory Simulation Studies
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DOI：
10.1021/acsami.8b20502
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发表时间：
2019-03-20
影响因子：
9.5
通讯作者：
Lei, Yu
中科院分区：
文献类型：
--
作者：
Kwak, Dongwook;Wang, Mengjing;Lei, Yu
研制了一种基于三氧化钼纳米带的高灵敏氨气传感器。采用水热法成功合成了a-MoO 3纳米带（MoO 3 NRs），并利用各种先进技术对其进行了系统表征。采用简单的滴铸工艺，在Au叉指电极上沉积MoO 3 NR敏感膜，制备了高性能的化学电阻式NH3传感器。在450 ℃的最佳工作温度下，MoO 3纳米带基传感器在低至50 ppb的NH3浓度下表现出优异的灵敏度（0.72），21 s的快速响应时间，良好的稳定性和再现性，以及对干扰气体（如H-2，NO2和O-2）的令人印象深刻的选择性。更重要的是，该传感器代表了280 ppt的显著检测限（基于信噪比3计算），这使得所制备的MoO 3 NR传感器成为文献中最灵敏的NH3传感器。此外，密度泛函理论（DFT）模拟，以了解吸附能量和电子结构，从而阐明传感性能的基本原理。NH3的增强灵敏度明确讨论和解释的显着的能带结构的修改，因为NH3吸附在a-MoO 3纳米带上的氧空位位置。这些结果验证了水热生长的MoO 3纳米带是一种有前途的传感材料，用于增强NH3气体监测。
A highly-sensitive ammonia (NH3) gas sensor based on molybdenum trioxide nanoribbons was developed in this study. a-MoO3 nanoribbons (MoO3 NRs) were successfully synthesized via a hydrothermal method and systematically characterized using various advanced technologies. Following a simple drop-cast process, a high-performance chemiresistive NH3 sensor was fabricated through the deposition of a MoO3 NR sensing film onto Au interdigitated electrodes. At an optimal operation temperature of 450 degrees C, the MoO3 nanoribbon-based sensor exhibited an excellent sensitivity (0.72) at NH3 concentration as low as 50 ppb, a fast response time of 21 s, good stability and reproducibility, and impressive selectivity against the interfering gases such as H-2, NO2, and O-2. More importantly, the sensor represents a remarkable limit of detection of 280 ppt (calculated based on a signal-to-noise ratio of 3), which makes the as-prepared MoO3 NR sensor the most sensitive NH3 sensor in the literature. Moreover, density functional theory (DFT) simulations were employed to understand the adsorption energetics and electronic structures and thus shed light on the fundamentals of sensing performance. The enhanced sensitivity for NH3 is explicitly discussed and explained by the remarkable band structure modification because of the NH3 adsorption at the oxygen vacancy site on a-MoO3 nanoribbons. These results verify that hydrothermally grown MoO3 nanoribbons are a promising sensing material for enhanced NH3 gas monitoring.