Study of novel ZIF materials with dual recognition of internal and external CO₂ and efficient CO₂/N₂ separation

Abstract

To address the growing issue of the greenhouse effect, CO₂ capture has emerged as a key area of research. In this paper, zeolite imidazolium salt framework-8 (ZIF-8) was synthesized via a one-step method involving the linkage and in situ growth of graphitic phase carbon nitride (g-C₃N₄) on iron trioxide (Fe₂O₃). Subsequently, the material was amine-functionalised, yielding the PEI-Fe-C-ZIF-8 adsorbent, which exhibited dual endo-external recognition capability. The adsorbent exhibited a high CO₂ adsorption capacity, which can rapidly adsorb CO₂ at room temperature and low pressure. The ideal adsorbed solution theory (IAST) selectivity for CO₂/N₂ (15/85) reached 963.76 at 298 K, 0–100 kPa. Molecular simulations revealed that the material trades partial specific surface area for an increased number of adsorption sites. The synergistic effect of multiple sites facilitated the separation of CO₂/N₂ by the material.

Keywords

CO₂ separation / ZIF-8 / surface modified / amine functionalization / Monte Carlo simulation

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Central South University