Nanosensors: towards morphological control of gas sensing activity. SnO2, In2O3, ZnO and WO3 case studies
Nanosensors: towards morphological control of gas sensing activity. SnO2, In2O3, ZnO and WO3 case studies
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DOI：
10.1039/c0nr00560f
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发表时间：
2011-01-01
期刊：
影响因子：
6.7
通讯作者：
Gurlo, Aleksander
中科院分区：
文献类型：
--
作者：
Gurlo, Aleksander
各向异性是单晶的基本性质。不同的刻面/表面具有不同的几何结构和电子结构，导致不同的功能特性。几个案例研究明确表明，金属氧化物的气敏活性是由暴露于环境气体的表面的性质决定的。因此，需要控制晶体形态，即控制晶体中面的角度关系、尺寸和形状，以开发在气体的化学测定中具有增加的选择性和灵敏度的更好的传感器。对这种纳米形态控制的气体传感性能的第一步是设计和合成的定义明确的纳米晶体是均匀的大小，形状和表面结构。这些材料具有对称集{hkl}的平面，因此在化学反应和吸附过程中必须表现相同。由于这些特性，形状控制的纳米晶体是气体传感机制的基础研究的理想候选者，其应涉及（i）特定表面上的气体传感测量，（ii）它们的原子/量子化学建模和（ii）在传感器的操作条件下在相同表面上获得的光谱信息。
Anisotropy is a basic property of single crystals. Dissimilar facets/surfaces have different geometric and electronic structure that results in dissimilar functional properties. Several case studies unambiguously demonstrated that the gas sensing activity of metal oxides is determined by the nature of surfaces exposed to ambient gas. Accordingly, a control over crystal morphology, i.e. over the angular relationships, size and shape of faces in a crystal, is required for the development of better sensors with increased selectivity and sensitivity in the chemical determination of gases. The first step toward this nanomorphological control of the gas sensing properties is the design and synthesis of well-defined nanocrystals which are uniform in size, shape and surface structure. These materials possess the planes of the symmetrical set {hkl} and must therefore behave identically in chemical reactions and adsorption processes. Because of these characteristics, the form-controlled nanocrystals are ideal candidates for fundamental studies of mechanisms of gas sensing which should involve (i) gas sensing measurements on specific surfaces, (ii) their atomistic/quantum chemical modelling and (ii) spectroscopic information obtained on same surfaces under operation conditions of sensors.