Composite From Superparamagnetic Iron Oxide Nanoparticles and Copper Benzene-1,3,5-Tricarboxylate as Rapidly Regenerated CO2 Adsorbent

Abstract

Rising global warming concerns drive the demand for cost-effective CO₂ capture technologies for industrial reuse. In this study, a novel composite material for CO₂ adsorption based on superparamagnetic iron oxide nanoparticles (SPIONs) and copper benzene-1,3,5-tricarboxylate (CuBTC) was proposed by a chronoamperometry electrochemical method. XRD, FT-IR, and SEM–EDX techniques confirmed the presence of SPION and CuBTC in the synthesized composites. SPIONs were small, uniform, and spherical, facilitating their effective combination with CuBTC. Among the synthesized composites, the 1:1 ratio of SPION to CuBTC exhibited the highest CO₂ adsorption capacity. Under controlled laboratory conditions (0°C, 1 bar, without the influence of ambient moisture or CO₂ diffusion limitations), the SPION/CuBTC 1:1 composite demonstrated a CO₂ adsorption capacity of 3.5 mmol/g. Under more realistic conditions (25°C, 1 bar, with the influence of ambient moisture) the SPION/CuBTC 1:1 composite exhibited the highest CO₂ adsorption efficiency of 12% (expressed as weigh percentage of dry sorbent). The CO₂ adsorption capacity of the composite decreased by more than half when the CO₂ concentration dropped from 100% to 15%. The adsorption mechanism is primarily driven by chemical adsorption via surface functional groups and physical adsorption through microcapillary formation and van der Waals interactions, mainly due to CuBTC. The incorporation of SPION in the composite accelerated the CO₂ desorption process. The combined magnetic behavior and heat generation results suggest that SPION/CuBTC composites possess enhanced magnetic properties and thermal responses, highlighting their potential for efficient heat-mediated desorption in industrial applications.