Oxygen Vacancies Modulation of Ammonium Tungsten Bronze by NH4+-Assisted Heat Treatment for Highly Sensitive Detection of NO2

en Introducing oxygen vacancies has emerged as an essential strategy to affect the sensing properties of nanomaterials. However, existing methods for manipulating oxygen require high cost, complex operation, and harsh conditions. Herein, a simple NH 4 + -assisted heat treatment approach was designed to regulate the concentration of oxygen vacancies of ammonium tungsten bronze ((NH 4 ) 0.25 WO 3 , named as NWO). The resultant NWO-300 sensor exhibited an extremely high response of 118 to 1 ppm NO 2 at 40°C. It achieved a detection limit as low as 10 ppb. Such outstanding sensing properties of NWO-300 were ascribed to the modulated electronic structure and increased active sites caused by oxygen vacancies. The formation of a large number of oxygen vacancies in NWO-300 is due to the H and N atoms in NH 3 can extract O atoms on the surface of materials, which was confirmed by X-ray photoelectron spectroscopy (XPS) and thermogravimetric-mass spectrometry (TG-MS) techniques. Moreover, the excellent NO 2 detection ability of the NWO-300 sensor enables the detection of air quality under different floors, and its development can be utilized in the field of environmental monitoring applications. 摘要 zh 引入氧空位已成为影响纳米材料传感性能的一项关键策略。然而, 现有调控氧空位的方法成本高昂、操作复杂且条件苛刻。因此, 设计了一种简单的NH 4 + 辅助热处理方法来调节铵钨青铜 ((NH 4 ) 0.25 WO 3 , 命名为NWO) 中氧空位的浓度。制备的NWO-300传感器在40 °C时对1 ppm 的NO 2 显示出高达118的响应, 其检测限低至10 ppb。NWO-300传感器如此出色的传感性能归因于氧空位所导致的电子结构的调节和活性位点的增加。NWO-300中大量氧空位的形成是由于NH 3 中的H和N原子可以从材料表面提取O原子, 这一点通过XPS和TG-MS技术得到了证实。此外, 由于NWO-300传感器出色的NO 2 检测能力使其能够检测不同楼层的空气质量, 其开发可用于环境监测领域。