CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei, 230026, China.
Research Center for Biomimetic Functional Materials and Sensing Devices, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031, China.
Chemosphere. 2018 Aug;204:202-209. doi: 10.1016/j.chemosphere.2018.04.050. Epub 2018 Apr 10.
Ammonia (NH), is a precursor for the formation of atmospheric fine particulate matter (PM), and thus establishing efficient and cost-effective methods to detect ammonia emission is highly desired. Transition metal oxide semiconductors-based sensors for electrochemical gas sensing have been extensively explored. Among various types of semiconductors, tungsten oxide (WO) possesses an anisotropic layered crystalline structure and is recognized as a promising material for gas sensing. However, the performance of commercial WO is unsatisfactory because of its high impedance and low charge transportation efficiency. Thus, the modification of commercial WO is needed to make it an efficient ammonia sensor material. In this work, closely packed WO microspheres with oxygen vacancies were synthesized successfully through a novel two-step hydrothermal route. Our WO showed a good selectivity to ammonia sensing, and its response intensity was 2.6 times higher than that of commercial WO because of its optimized conductivity. Moreover, the mechanism behind its robust ammonia sensing performance was elucidated. The effectiveness of the as-prepared WO microspheres for ammonia sensing also suggests a new strategy for modifying transition metal oxide materials.
氨（NH）是大气细颗粒物（PM）形成的前体，因此，人们非常希望建立高效且具有成本效益的氨排放检测方法。基于过渡金属氧化物半导体的电化学气体传感器已经得到了广泛的研究。在各种类型的半导体中，氧化钨（WO）具有各向异性层状晶体结构，被认为是一种很有前途的气体传感材料。然而，由于商业 WO 的阻抗高、电荷传输效率低，其性能并不令人满意。因此，需要对商业 WO 进行改性，使其成为一种高效的氨传感器材料。在这项工作中，通过一种新颖的两步水热法成功合成了具有氧空位的紧密堆积 WO 微球。我们的 WO 对氨传感表现出良好的选择性，其响应强度比商业 WO 高 2.6 倍，这是因为其导电性得到了优化。此外，还阐明了其具有稳健氨传感性能的机制。所制备的 WO 微球在氨传感方面的有效性也为过渡金属氧化物材料的改性提供了一种新策略。
