Opportunity and Challenge of Emerging COFs in Chemiresistive Sensing for Gas and Humidity

Novel 2D materials for chemiresistive sensors are attractive due to their large surface area and structure diversity. Covalent organic frameworks (COFs) have received much attention due to their unique properties, including the abundant choice of organic building units, permanent pore structure and crystallinity, which show huge potential of implement in gas and humidity detection in complex environment. Recently, the development of the synthesis and modification methods for COFs powder and film contributes to the sensitivity and compatibility in chemiresistive sensors and integrated devices. In the present review, the current synthesis methods of COFs powder and film as well as their application in the chemiresistive sensors are summarized. The current challenge and future modification strategy are discussed for the further development of COFs as active materials in gas and humidity sensors.