Cubic mesoporous Ag@CN: a high performance humidity sensor

Abstract

The fabrication of highly responsive, rapid response/recovery and durable relative humidity (%RH) sensors that can precisely monitor humidity levels still remains a considerable challenge for realizing the next generation humidity sensing applications. Herein, we report a remarkably sensitive and rapid %RH sensor having a reversible response using a nanocasting route for synthesizing mesoporous g-CN (commonly known as g-CN). The 3D replicated cubic mesostructure provides a high surface area thereby increasing the adsorption, transmission of charge carriers and desorption of water molecules across the sensor surfaces. Owing to its unique structure, the mesoporous g-CN functionalized with well dispersed catalytic Ag nanoparticles exhibits excellent sensitivity in the 11-98% RH range while retaining high stability, negligible hysteresis and superior real time %RH detection performances. Compared to conventional resistive sensors based on metal oxides, a rapid response time (3 s) and recovery time (1.4 s) were observed in the 11-98% RH range. Such impressive features originate from the planar morphology of g-CN as well as unique physical affinity and favourable electronic band positions of this material that facilitate water adsorption and charge transportation. Mesoporous g-CN with Ag nanoparticles is demonstrated to provide an effective strategy in designing high performance %RH sensors and show great promise for utilization of mesoporous 2D layered materials in the Internet of Things and next generation humidity sensing applications.

Embedding 1D Conducting Channels into 3D Isoporous Polymer Films for High‐Performance Humidity Sensing

“…Furthermore,t he response curve for adsorption and desorption exhibited negligible hysteresis,i ndicating good reliability of the sensor and low vapor residence time. [15] (Figure 2f). It is noteworthy that owing to the miniaturized size of the present sensors, arrays of such sensors can be fabricated on as mall piece of film (Figure 2f,inset).…”

Fully printed high performance humidity sensors based on two-dimensional materials

“…3 Generally, an ideal humidity sensor material requires high sensitivity, a wide humidity detection range, a quick response and short recovery time, as well as the potential for inexpensive large scale fabrication. 5 Humidity responsiveness normally relies on the total area of the sensing material exposed to moisture molecules; thus a range of different humidity sensitive materials with large specific surface areas have been developed in recent years, including: metal oxide nanorods or nanotubes, 6,7 semiconductor nanoparticles or nanowires, [9][10][11] and carbon nanotubes. 12,13 These materials have shown improvements in the sensitivity.…”

Embedding 1D Conducting Channels into 3D Isoporous Polymer Films for High‐Performance Humidity Sensing

“…It is apparent that the resistance change of the sensor can be correlated to the orderly water vapor uptake by the nanoporous polymer matrix at room temperature as well as at 50 °C, indicating similar chemiresistive behavior at elevated temperature (Supporting Information, Figure S9 b,c). Furthermore, the response curve for adsorption and desorption exhibited negligible hysteresis, indicating good reliability of the sensor and low vapor residence time . (Figure f).…”