Ag Nanoparticle-Sensitized WO3 Hollow Nanosphere for Localized Surface Plasmon Enhanced Gas Sensors

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• 作者：Yao Yao ; Fangxu Ji ; Mingli Yin ; Xianpei Ren ; Qiang Ma ; Junqing Yan ; Shengzhong Frank Liu
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：July 20, 2016
• 年：2016
• 卷：8
• 期：28
• 页码：18165-18172
• 全文大小：555K
• 年卷期：0
• ISSN：1944-8252

文摘

Ag nanoparticle (NP)-sensitized WO₃ hollow nanospheres (Ag-WO₃–HNSs) are fabricated via a simple sonochemical synthesis route. It is found that the Ag-WO₃–HNS shows remarkable performance in gas sensors. Field-emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM) images reveal that the Ag_x-WO₃ adopts the HNS structure in which WO₃ forms the outer shell framework and the Ag NPs are grown on the inner wall of the WO₃ hollow sphere. The size of the Ag NPs can be controlled by adjusting the addition amount of WCl₆ during the reaction. The sensor Ag_x-WO₃ exhibits extremely high sensitivity and selectivity toward alcohol vapor. In particular, the Ag_(15nm)-WO₃ sensor shows significantly lower operating temperature (230 °C), superior detection limits as low as 0.09 ppb, and faster response (7 s). Light illumination was found to boost the sensor performance effectively, especially at 405 and 900 nm, where the light wavelength resonates with the absorption of Ag NPs and the surface oxygen vacancies of WO₃, respectively. The improved sensor performance is attributed to the localized surface plasmon resonance (LSPR) effect.