Humidity sensing mechanism of mesoporous MgO/KCl-SiO₂ composites analyzed by complex impedance spectra and bode diagrams

详细信息    查看全文

• 作者：Wangchang Geng^a ; ^{w.geng@nwpu.edu.cn}Author Vitae ; Qing Yuan^bAuthor Vitae ; Xingmao Jiang^cAuthor Vitae ; Jinchun Tu^dAuthor Vitae ; Libing Duan^aAuthor Vitae ; Junwei Gu^aAuthor Vitae ; Qiuyu Zhang^a ; ^{qyzhang@nwpu.edu.cn}Author Vitae
• 关键词：Humidity sensing ; Composites ; Mesoporous silica ; Complex impedance spectra ; Bode diagrams
• 刊名：Sensors and Actuators B: Chemical
• 出版年：2012
• 出版时间：November, 2012
• 年：2012
• 卷：174
• 期：Complete
• 页码：513-520
• 全文大小：1525 K

文摘

Composites of mesoporous silica SBA-15 and MgO/KCl were prepared by a simple grind method following a heat-treatment process. Their structures were characterized by X-ray diffraction (XRD). Humidity sensing properties were studied and the results indicated that, under the same preparation condition, KCl-SBA-15 composite was more suitable to be a promising humidity sensing material than MgO-SBA-15 composite. The impedance of KCl-SBA-15 composite changed more than four orders of magnitude when relative humidity changed from 11 % to 95 % . The response and recovery time were about 6 s and 26 s, respectively. High stability and low hysteresis were also observed. Complex impedance spectra, the corresponding equivalent circuit, and bode diagrams under different relative humidity was analyzed to explore the humidity sensing mechanism of this material.