Chemiresistive gas sensors based on layered double hydroxides (LDHs) structures: A review

A wide range of materials and nanomaterials have been considered gas sensors due to the growing needs of developed and developing societies. It has been more than six decades since Taguchi introduced the first commercial gas sensor, yet the development of sensors has grown exponentially and has not slowed down. Researchers always look for new materials with more efficient morphologies. It can probably be said that one of the newest materials discussed is LDH nanosheets, which has been discussed for less than two decades. Thus, in this review, after defining the general structure of LDH and giving a general description of nanomaterials, we have discussed the relevant terms and various methods of synthesis. The film preparation of nanomaterial sensor is then discussed in detail as a scalable approach in line with the various methods of nanomaterial synthesis (especially with a focus on LDH nanosheets). The following is discussed the unique properties of LDH nanosheets and their effect on the detection of various contaminants. Since LDH nanomaterials fall into both n- and p-type categories, the pollutant (gas) measurement approach has been investigated in both categories. This creates a specific comparative approach for the reader. Concisely, this study describes the use of LDH nanosheets in the field of gas sensors and may provide the idea for more extensive and practical research on LDHs.