Cao Jing, Zhang Ningrui, Wang Shuangming, Zhang Haiming
School of Physical Science and Technology, Tiangong University, Tianjin 300387, People's Republic of China.
School of Physical Science and Technology, Tiangong University, Tianjin 300387, People's Republic of China.
J Colloid Interface Sci. 2020 Oct 1;577:19-28. doi: 10.1016/j.jcis.2020.05.028. Epub 2020 May 21.
Constructing p-n heterojunction is considered as an effective approach to improve gas-sensing performance of nanomaterials, and the general focus is that the formation of a p-n junction can effectively broaden the electron-depletion layer, enhancing the amount of the adsorption oxygen, and being beneficial to the improvement of the gas-sensing performance. However the widening of the depletion layer can only contribute to the improvement of the sensitivity, the effect of p-n junction on other sensing parameters is still not well understood. Herein, the InO/CoO core/shell hierarchical heterostructures (InO/CoO HHS) are investigated to discern how p-n junction alters the sensing process. The construction of p-n junction can effectively adjust Fermi level, influence the oxidation ability of the adsorbed oxygen and significantly heighten the selectivity of sensing materials, resulting in superior sensing activity. Especially, InO/CoO HHS exhibits obviously enhanced gas sensing performance toward formaldehyde at 180 °C with high response and good selectivity. Our findings promote the recognition of the important role of electronic structure on gas sensing performance and provide a new strategy to design sensing materials for gas detection.
构建p-n异质结被认为是提高纳米材料气敏性能的有效途径，普遍的观点是p-n结的形成可以有效地拓宽电子耗尽层，增加吸附氧的量，有利于气敏性能的提高。然而，耗尽层的拓宽仅有助于灵敏度的提高，p-n结对其他传感参数的影响仍未得到很好的理解。在此，研究了InO/CoO核壳分级异质结构（InO/CoO HHS），以了解p-n结如何改变传感过程。p-n结的构建可以有效地调节费米能级，影响吸附氧的氧化能力，并显著提高传感材料的选择性，从而产生优异的传感活性。特别是，InO/CoO HHS在180°C下对甲醛表现出明显增强的气敏性能，具有高响应和良好的选择性。我们的研究结果促进了对电子结构在气敏性能中重要作用的认识，并为设计用于气体检测的传感材料提供了新策略。
