Solution-Processed Gas Sensors Employing SnO2 Quantum Dot/MWCNT Nanocomposites

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• 作者：Huan Liu ; Wenkai Zhang ; Haoxiong Yu ; Liang Gao ; Zhilong Song ; Songman Xu ; Min Li ; Yang Wang ; Haisheng Song ; Jiang Tang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：January 13, 2016
• 年：2016
• 卷：8
• 期：1
• 页码：840-846
• 全文大小：431K
• ISSN：1944-8252

文摘

Solution-processed SnO₂ colloidal quantum dots (CQDs) have emerged as an important new class of gas-sensing materials due to their potential for low-cost and high-throughput fabrication. Here we employed the design strategy based on the synergetic effect from highly sensitive SnO₂ CQDs and excellent conductive properties of multiwalled carbon nanotubes (MWCNTs) to overcome the transport barrier in CQD gas sensors. The attachment and coverage of SnO₂ CQDs on the MWCNT surfaces were achieved by simply mixing the presynthesized SnO₂ CQDs and MWCNTs at room temperature. Compared to the pristine SnO₂ CQDs, the sensor based on SnO₂ quantum dot/MWCNT nanocomposites exhibited a higher response upon exposure to H₂S, and the response toward 50 ppm of H₂S at 70 °C was 108 with the response and recovery time being 23 and 44 s. Because of the favorable energy band alignment, the MWCNTs can serve as the acceptor of the electrons that are injected from H₂S into SnO₂ quantum dots in addition to the charge transport highway to direct the electron flow to the electrode, thereby enhancing the sensor response. Our research results open an easy pathway for developing highly sensitive and low-cost gas sensors.