Magnesium and Nitrogen Co-Doped Mesoporous Carbon with Enhanced Microporosity for CO₂ Adsorption

Efficacies of Carbon-Based Adsorbents for Carbon Dioxide Capture

Carbon dioxide (CO2), a major greenhouse gas, capture has recently become a crucial technological solution to reduce atmospheric emissions from fossil fuel burning. Thereafter, many efforts have been put forwarded to reduce the burden on climate change by capturing and separating CO2, especially from larger power plants and from the air through the utilization of different technologies (e.g., membrane, absorption, microbial, cryogenic, chemical looping, and so on). Those technologies have often suffered from high operating costs and huge energy consumption. On the right side, physical process, such as adsorption, is a cost-effective process, which has been widely used to adsorb different contaminants, including CO2. Henceforth, this review covered the overall efficacies of CO2 adsorption from air at 196 K to 343 K and different pressures by the carbon-based materials (CBMs). Subsequently, we also addressed the associated challenges and future opportunities for CBMs. According to this review, the efficacies of various CBMs for CO2 adsorption have followed the order of carbon nanomaterials (i.e., graphene, graphene oxides, carbon nanotubes, and their composites) < mesoporous -microporous or hierarchical porous carbons < biochar and activated biochar < activated carbons.

Effects of Alkali Metal (Li, Na, and K) Incorporation in NH₂⁻MIL125(Ti) on the Performance of CO₂ Adsorption

A series of titanium-based, metal–organic framework (MOF) materials, xM@NH₂-MIL125(Ti) (x is the alkali metal loading percentage during the synthesis; M = Li, Na, K), have been synthesized solvothermally. Alkali metal doping in the NH₂–MIL125(Ti) in situ solvothermal process demonstrated a vital modification of the material structure and surface morphology for the CO₂ adsorption capacity at ambient conditions. By changing the reactants’ precursor, including different kinds of alkali metal, the morphology of xM@NH₂–MIL125(Ti) can be adjusted from a tetragonal plate through a circular plate to a truncated octahedron. The variation of the alkali metal loading results in substantial differences in the CO₂ adsorption. The properties of xM@NH₂–MIL125(Ti) were evaluated via functional group coordination using FT-IR, phase identification based on X-ray diffraction (XRD), surface morphology through scanning electron microscopy (SEM), as well as N₂ and CO₂ adsorption by physical gas adsorption analysis. This work reveals a new pathway to the modification of MOF materials for high-efficiency CO₂ adsorption.

Preparation and Application of Hybrid Nanomaterials

The growing demand of new materials with tailored physicochemical properties has propelled hybrid materials to a position of prominence in materials science by virtue of their remarkable new properties and multifunctional nature. [...].