Enhanced sensitivity of hydrogenated α-Fe2O3 nanoplates having {001} facets and the gas sensing mechanism
Enhanced sensitivity of hydrogenated α-Fe2O3 nanoplates having {001} facets and the gas sensing mechanism
复制标题
具有{001}面和气体传感机制的氢化α-Fe2O3纳米板的增强灵敏度
DOI：
10.1007/s10854-021-07555-1
复制
发表时间：
2022-01-27
影响因子：
2.8
通讯作者：
Yang，Heqing
中科院分区：
文献类型：
--
作者：
Meng，Xiaohua;Qi，Chen;Yang，Heqing
以乙醇为晶面控制剂，合成了暴露{001}晶面的六方α-Fe2O3纳米片。与商业粉末相比，合成的纳米板对乙醇、甲醇和三乙胺表现出更高的响应，并且可以通过氢化进一步增强响应。灵敏度的增强归因于氢化后暴露的（001）晶面处的3配位Fe（Fe3c）原子密度的增加。 Fe 封端的极性 (001) 表面的不饱和 Fe3c 原子被证明可以作为气体传感的活性位点，并提出了原子尺度的气体传感机制。在(001)表面，3配位的Fe原子吸附氧并催化吸附氧与测试气体的反应。氧气的吸附和解吸导致α-Fe2O3纳米板传感器的电阻发生变化。该机制对于理解气敏反应以及高灵敏度气敏材料和器件的设计具有指导意义。
Hexagonal α-Fe2O3nanoplates exposing {001} crystal planes have been synthesized by using ethanol as the control agent of crystal facets. The as-synthesized nanoplates exhibit higher responses to ethanol, methanol and triethylamine than commercial powders, and the responses can be further increased by hydrogenation. The enhancement of sensitivity is attributed to an increase in density of 3-coordinated Fe (Fe3c) atoms at the exposed (001) crystal plane after hydrogenating. The unsaturated Fe3catoms at the Fe-terminated polar (001) surface are evidenced to serve as an active site for gas sensing, and a gas sensing mechanism at atomic scale is presented. On the (001) surface, the 3-coordinated Fe atoms adsorb oxygen and catalyzes the reaction of the adsorb oxygen with test gases. The adsorption and desorption of oxygen leads to a change in resistance of the α-Fe2O3nanoplate sensor. This mechanism is instructive for the comprehending of gas sensing reactions, and the design of highly sensitivity gas sensing materials and devices.