Metal-organic frameworks bearing free carboxylic acids: Preparation, modification, and applications

Metal-organic frameworks (MOFs) bearing free –COOH groups (MOF-COOHs) have attracted particular attention in the field of MOF research. Several MOF-COOHs have been prepared by direct and post-synthetic modification methods, showing remarkable progress and prospects in applications such as adsorption, catalysis, proton conductivity, sensing, and precursors for other functions. This review summarizes the state-of-the-art advances and applications of MOF-COOHs, while suggesting future perspectives in additional fields based on the progress and achievements so far.