Humidity Detection Using Metal Organic Framework Coated on QCM

Abstract EN

Quartz crystal microbalance (QCM) coated with poly-4-vinylpyridine (PVP) and metal organic framework HKUST-1 are investigated and compared for humidity sensing.

Drop casting method is employed to coat the PVP and HKUST-1 solutions onto the surface of a quartz crystal microbalance.

The resonance frequencies of these sensors with varying relative humidity (RH) from 22% RH to 69% RH are measured using impedance analysis method.

The sensitivity, humidity hysteresis, response, and recovery times of these sensors are studied.

The sensitivities of uncoated, PVP, and HKUST-1 coated QCM sensors are 7 Hz, 48 Hz, and 720 Hz, respectively, in the range of 22% RH–69% RH.

The extraction of desorption rate and adsorption energy associated with the adsorption and desorption of water molecules on these surfaces reveals that HKUST-1 has better sensing properties than PVP and uncoated QCM sensors.

In this work, the HKUST-1 coated QCM is shown to be a promising material for moisture detection.