Advances in microporous framework materials as chemiresistive gas sensors

In order to timely and effectively detect the harmful gases emitted into the atmosphere which pose serious risks to the human health and human living environment, the efficient detection of gases is great meaningful. Microporous framework materials (MFMs), such as metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), are constructed by assembly of building blocks (e.g. organic linkers/metal ion or metal cluster, mixed organic linkers) with regular microporous structures and record-breaking surface area, have been widely used as functional materials to manufacture chemiresistive gas sensor with excellent sensitivity, selectivity, stability and long lifetime. Numerous novel materials (such as conductive MOFs and COFs), versatile manipulation strategies for MFMs structure synthesis and film preparation, and fascinating gas sensing properties have erupted in the last ten years. In this review, there was a presentation on the comprehensive progress of chemiresistive sensors developed through the use of MFMs. Firstly, the basic principles of MFM-based chemiresistive sensor were elucidate. Then, the recent advancements of MFMs-based chemiresistive sensor were present in detail. In this section, key focus is allocated to the structures and morphology of MFMs, and their corresponding sensing performance. The well-defined structures MFMs significantly enhance our understanding of the relationships between structure and sensing properties. Finally, the challenges and future trends in this field was discussed.