Fabrication a sensor based on sulfonate-based COF for humidity sensing

Sensing material is crucial to the performance of humidity sensors. Porous material is widely used for humidity sensing but suffers from the narrow detecting range and slow response speed. Herein, the porous TpBDSA-Na COF with a large pore size (∼1.7 nm) and high density of hydrophilic active sites is used as sensing material for humidity detector. The superior adsorption capacity of water molecules (∼396 mg/g) in TpBDSA-Na COF makes the humidity detector exhibit fast response speed (18/9 s), small hysteresis (∼3% RH) and long-term stability (∼20 days) in 11%–95% RH range. Moreover, the sensing mechanism of TpBDSA-Na sensor is also discussed in detail. This research indicates the 2D COF with a hydrophilic channel can be used as a promising material for humidity sensing.