Single-Atoms on Covalent or Metal-Organic Frameworks: Current Findings and Perspectives for Pollutants Abatement, Hydrogen Evolution, and Reduction of CO 2 .

Nowadays, attention to single-atoms and also porous structures like metal-organic frameworks (MOFs) and covalent-organic frameworks (COFs) for the preparation of high-performance material is expanding rapidly. These dazzling materials with unprecedented properties have lots of applications, especially as promising catalysts for organic pollutants abatement, hydrogen evolution, reduction of CO 2 , etc. To provide an in-depth understanding, in this mini-review, we begin with a brief description and a general background about single-atoms, COFs, as well as MOFs. After considering some fundamentals, the synergism effects, advantages, and their applications are discussed.