Fast response with high performance humidity sensing of Ag–SnO2/SBA-15 nanohybrid sensors

• Mesoporous SnO2/SBA-15 was synthesized by in-situ hydrothermal processes.
• Ag nanoparticles were loaded in SnO2/SBA-15 using wet impregnation process.
• Impedance of Ag–SnO2/SBA-15 sensor changes from 108 Ω to 102 Ω in 11–98%RH range.
• The sensor displays superfast response (5 s) and recovery time (8 s).

In this work, a simple and straight forward technology of loading Ag nanoparticles in SnO2/SBA-15 nanocomposite for measuring room temperature relative humidity (RH) is demonstrated. The nanocomposite SnO2/SBA-15 comprising Ag nanoparticles exhibit several fundamental characteristics, such as high specific surface area, open porous structure and good interconnectivity. Therefore, the RH sensors based on Ag–SnO2/SBA-15 hybrid nanocomposite shows very high sensitivity and ultrafast response/recovery time to humidity, which outperform current porous structure based sensors. The impedance of synthesized nanocomposite sensor varies from 108 Ω to 102 Ω between 11 RH% and 98 RH%, the humidity range required for a sensor to operate at ambient humidity. Moreover, the resultant sensors also display relatively small hysteresis and long-term stability. This study demonstrates that Ag–SnO2/SBA-15 complex hybrid material is a step towards fabricating futuristic high performance humidity sensors.

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