Adhyapak Parag V, Bang Amruta D, More Pooja, Munirathnam N R
Centre for Materials for Electronics Technology Panchawati, Pashan Road Pune 411008 India
Savitribai Phule Pune University Pune 411007 India.
RSC Adv. 2018 Oct 4;8(59):34035-34040. doi: 10.1039/c8ra06065g. eCollection 2018 Sep 28.
WO has emerged as an outstanding nanomaterial composite for gas sensing applications. In this paper, we report the synthesis of WO using two different capping agents, namely, oxalic acid and citric acid, along with cetyltrimethyl ammonium bromide (CTAB). The effect of capping agent on the morphology of WO material was investigated and presented. The WO materials were characterized using X-ray diffraction analysis (XRD), field emission transmission electron microscopy (FETEM), field emission scanning electron microscopy (FESEM), particle size distribution (PSD) analysis, and UV-visible spectroscopic analysis. WO synthesized using oxalic acid exhibited orthorhombic phase with crystallite size of 10 nm, while WO obtained using citric acid shows monoclinic phase with crystallite size of 20 nm. WO obtained using both capping agents were used to study their gas sensing characteristics, particularly for NO gas. The cross sensitivity towards interfering gases and organic vapors such as acetone, ethanol, methanol and triethylamine (TEA) was monitored and explained. Furthermore, the composites of WO were prepared with graphene by physical mixing to improve the sensitivity, response and recovery time. The composites were tested for gas sensing at room temperature as well as at 50 °C and 100 °C. The results indicated that the citric acid-assisted WO material exhibits better response towards NO sensing when compared with oxalic acid-assisted WO. Moreover, the sensitivity of the WO/graphene nanocomposite was better than that of the pristine WO material towards NO gas. The WO composite prepared using citric acid as capping agent and graphene exhibits sensing response and recovery time of 29 and 24 s, respectively.
WO已成为用于气体传感应用的一种出色的纳米材料复合材料。在本文中，我们报告了使用两种不同的封端剂，即草酸和柠檬酸，以及十六烷基三甲基溴化铵（CTAB）合成WO的方法。研究并展示了封端剂对WO材料形态的影响。使用X射线衍射分析（XRD）、场发射透射电子显微镜（FETEM）、场发射扫描电子显微镜（FESEM）、粒度分布（PSD）分析和紫外可见光谱分析对WO材料进行了表征。用草酸合成的WO呈现正交相，微晶尺寸为10纳米，而用柠檬酸获得的WO显示单斜相，微晶尺寸为20纳米。使用这两种封端剂获得的WO被用于研究它们的气敏特性，特别是对NO气体的气敏特性。监测并解释了对干扰气体和有机蒸汽如丙酮、乙醇、甲醇和三乙胺（TEA）的交叉敏感性。此外，通过物理混合将WO与石墨烯制备成复合材料以提高灵敏度、响应和恢复时间。在室温以及50℃和100℃下对复合材料进行气敏测试。结果表明，与草酸辅助的WO相比，柠檬酸辅助的WO材料对NO传感表现出更好的响应。此外，WO/石墨烯纳米复合材料对NO气体的灵敏度优于原始WO材料。使用柠檬酸作为封端剂和石墨烯制备的WO复合材料的传感响应和恢复时间分别为29秒和24秒。
