UV activated monolithic graphene Oxide-Based adsorbents for dynamic CO2 Capture: Kinetic, isotherm and thermodynamic studies

Abstract

In this research article, the synthesis of monolithic graphene oxide-based adsorbent was prepared by the self-assembly process of graphene oxide followed by oxalic acid reduction with various mass ratios and activated by UV treatments. The optimized adsorbent reveals an excellent dynamic CO2 capture capacity of 1.65 mmol g−1 at 25 °C, owing to its elevated BET surface area of 577.3 m2/g. Considering the desorption step with a constant volume flow rate, it becomes evident that the pressure drop results in excessive consumption of desorbing gas (N2) approximately 50 % for the regeneration process. Several studied were investigated; the regenerability of 98.8 %, an excellent CO2/N2 selectivity, fast kinetics, the pseudo-second-order kinetic model and Freundlich isotherm model were best fitted. Thermodynamic studies reveal the heterogeneity of adsorption site, the adsorption process endothermic nature, as indicated by ΔH° value of + 13.1154139 KJ mol−1, underscoring the distinctive characteristic property of chemisorption.