Synthesis and effect of metal–organic frame works on CO₂ adsorption capacity at various pressures: A contemplating review

The most important environmental challenge that the world is facing today is the control of the quantity of CO₂ in the atmosphere, because it causes global warming. Increase in the global temperature results in greenhouse gas emission, interruption of the volcanic activity, and climatic changes. The alarming rise of the CO₂ level impels to take some serious action to control these climatic changes. Various techniques are being utilized to capture CO₂. However, chemical absorption and adsorption are supposed to be the most suitable techniques for post-combustion CO₂ capture, but the main focus is on adsorption. The aim of this study is to provide a brief overview on the CO₂ adsorption by a novel class of adsorbents called the metal–organic framework. The metal–organic framework is a porous material having high surface area with high CO₂ adsorption capacity. The metal–organic frameworks possess dynamic structure and have large capacity to adsorb CO₂ at either low pressure or high pressure due to its cavity size and surface area. Adsorption of CO₂ in the metal–organic framework at various pressures depends upon pore volume and heat of adsorption correspondingly. In this review, different synthesis methods of the metal–organic framework such as slow evaporation, solvo thermal, mechanochemical, electrochemical, sonochemical, and microwave-assisted synthesis are briefly described as the structure of the metal–organic frameworks are mostly dependent upon synthesis techniques. In addition to this, different strategies are discussed to increase the CO₂ adsorption capacity in the metal organic-framework. (Figure presented.).