Regulating the dissociation of LiCl and transportation of Li ions within UiO-66-NH2 framework for humidity sensing applications with superb comprehensive performances

摘要

The novel humidity sensor, fabricated from inorganic electrolyte doped porous metal-organic framework composite (denoted as LiCl@UiO-66-NH2), is reported in the present work. The humidity sensing properties of LiCl@UiO-66-NH2 composites have been investigated. The much higher comprehensive sensing properties of composites are obtained in LiCl@UiO-66-NH2 with 12.5 wt% LiCl. It shows the excellent linearity (R-2 = 0.994) in a broad relative humidity (RH) range. The impedance modulus of LiCl@UiO-66-NH2 (12.5 wt%) decreases nearly four orders of magnitude from 33% RH to 95% RH at 100 Hz. Besides, the LiCl@UiO-66-NH2 (12.5 wt%) humidity sensor exhibits fast response (6s) and recovery (18s) speed and excellent long-term stability. The sensing mechanism was discussed through the investigation of complex impedance curves. These results suggest that LiCl@UiO-66-NH2 have the potential application in humidity sensing. Our work offers a promising strategy for the fabrication of high performance humidity sensors. (C) 2019 Elsevier B.V. All rights reserved.