Hierarchical WO₃ nanomesh, assembled from single-crystalline WO₃ nanowires, is prepared via a hydrothermal method using thiourea (Tu) as the morphology-controlling agent. Formation of the hierarchical architecture comprising of WO₃ nanowires takes place via Ostwald ripening mechanism with the growth orientation. The sensor based on WO₃ nanomesh has good electrical conductivity and is therefore suitable as NO₂ sensing material. The WO₃ nanomesh sensor exhibited high response, short response and recovery time, and excellent selectivity towards ppb-level NO₂ at low temperature of 160 ℃. The superior gas performance of the sensor was attributed to the high-purity hexagonal WO₃ with high specific surface area, which gives rise to enhanced surface adsorption sites for gas adsorption. The electron depletion theory was used for explaining the NO₂-sensing mechanism by the gas adsorption/desorption and charge transfer happened on the surface of WO₃ nanomesh.

中文翻译：

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纳米线组装的WO 3纳米网，可在低温下快速检测ppb级NO 2

由单晶WO ₃纳米线组装而成的分层WO ₃纳米网是通过使用硫脲（Tu）作为形态控制剂的水热法制备的。包含WO ₃纳米线的分层体系结构的形成是通过具有生长方向的奥斯特瓦尔德成熟机制进行的。基于WO ₃纳米网的传感器具有良好的导电性，因此适合用作NO ₂传感材料。WO ₃纳米网状传感器表现出高响应，短响应和恢复时间以及对ppb级NO _2的优异选择性在160℃的低温下。传感器的优异气体性能归因于具有高比表面积的高纯度六角形WO ₃，从而提高了气体吸附的表面吸附位。利用电子耗竭理论通过WO ₃纳米网表面的气体吸附/解吸和电荷转移来解释NO _2的感应机理。