Acetone sensing mechanism of PdO-modified hexagonal WO3 (001) surface: DFT calculations
Acetone sensing mechanism of PdO-modified hexagonal WO3 (001) surface: DFT calculations
复制标题
PdO 修饰的六方 WO3 (001) 表面的丙酮传感机制：DFT 计算
DOI：
10.1016/j.apsusc.2019.143532
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发表时间：
2019-11-30
影响因子：
6.7
通讯作者：
Hu, Jifan
中科院分区：
文献类型：
--
作者：
Cao, Yue;Qin, Hongwei;Hu, Jifan
用密度泛函理论研究了PdO修饰的六方晶系WO 3（001）表面的丙酮传感机理。结果表明，与纯h-WO（3）（001）表面相比，PdO改性后的h-WO（3）（n-型半导体材料）表面能增加丙酮的吸附位，并使丙酮向材料表面的电荷转移量急剧增加，从而降低了hWO（3）的电阻.此外，我们发现氧气浓度和实验温度对Pd O修饰的h-WO 3（001）表面的丙酮敏感性有显著影响。在缺氧环境中，来自丙酮的O容易吸附在W或Pd位点上。随着温度的升高，丙酮从材料中解吸，解释了实验中观察到的h-WO 3传感器用于丙酮的最佳操作温度。此外，在富氧环境中，一些中间产物的产生，这表明一个替代的考虑丙酮传感机制的解释。
DFT calculations are used to investigate the acetone sensing mechanism of PdO-modified hexagonal WO3 (001) surface. It is concluded that compared to the pure h-WO3 (001) surface, modifying the surface with PdO could increase the available adsorption sites for acetone and leads to a sharp increase in the amount of charge transferred from acetone to the surface of the material, which contributes to a decrease in the resistance of hWO(3) (n-type semiconductor material). Moreover, we found that the oxygen concentration and experimental temperature have significant effects on the acetone sensitivity of the PdO-modified h-WO3 (001) surface. In an anoxic environment, the O originating from acetone easily adsorbs on a W or Pd site. With increasing temperature, acetone desorbs from the material, explaining the optimal operating temperature of h-WO3 sensors for acetone observed in experiments. Moreover, in oxygen-rich environments, some intermediate products were generated, which suggests an alternative consideration for the interpretation of acetone sensing mechanism.