Faculty of Applied Sciences, Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands.
Faculty of Applied Sciences, Department of Radiation Science and Technology, Delft University of Technology, Mekelweg 15, 2629 JB Delft, The Netherlands.
Nat Commun. 2017 Jun 5;8:15718. doi: 10.1038/ncomms15718.
Hydrogen detection is essential for its implementation as an energy vector. So far, palladium is considered to be the most effective hydrogen sensing material. Here we show that palladium-capped hafnium thin films show a highly reproducible change in optical transmission in response to a hydrogen exposure ranging over six orders of magnitude in pressure. The optical signal is hysteresis-free within this range, which includes a transition between two structural phases. A temperature change results in a uniform shift of the optical signal. This, to our knowledge unique, feature facilitates the sensor calibration and suggests a constant hydrogenation enthalpy. In addition, it suggests an anomalously steep increase of the entropy with the hydrogen/metal ratio that cannot be explained on the basis of a classical solid solution model. The optical behaviour as a function of its hydrogen content makes hafnium well-suited for use as a hydrogen detection material.
氢的检测对于将其作为能源载体至关重要。到目前为止，钯被认为是最有效的氢气感应材料。在这里，我们表明，在压力范围内超过六个数量级的氢气暴露下，钯覆盖的铪薄膜显示出高度可重复的光学传输变化。在这个范围内，光学信号没有滞后，其中包括两个结构相之间的转变。温度变化会导致光学信号均匀移动。这种独特的特性有助于传感器校准，并表明氢焓值恒定。此外，它还表明氢/金属比的熵异常陡峭增加，这不能用经典的固溶体模型来解释。其氢含量的光学行为使得铪非常适合用作氢气检测材料。
