Etching strategies induced multihierarchical structures of MOFs and their derivatives for gas sensing applications: a review

A growing need for accurate monitoring of both outdoor and indoor pollution sources demands enhanced gas sensors with improved sensitivity, selectivity, stability, fast response and low detection limits. Metal-organic frameworks (MOFs), a class of porous materials, stand out as superior candidates for high performance gas detection due to their exceptional structure characteristics, including tunable porosity, limitless structural motifs, and customizable chemical components. Tailoring the structure and functionalization of MOFs through etching has opened up new opportunities to adjust the gas-sensing capabilities of MOFs. In this review article, we provide a concise overview of the most recent advancements in three distinct aspects of etching MOFs: pore engineering, chemical modification, and transformation of MOFs into targeted derivatives. Despite extensive progress, research on etching strategies to elucidate the intricate relationship between the innovative structure and the sensing properties remains in its infancy. Focusing on MOFs and their derivative-based gas sensors with distinct critical structural features, the schemes to enhance sensor performance are introduced. We also outline the current barriers and future prospects in the field of gas sensing. This review seeks to offer guidance on modulating MOF-based gas sensors by strategically applying efficient etching methods, navigating contemporary challenges and future prospects in the gas sensing field.