High capture capacity of CO2 in a nickel intercalated Ti3C2Tx MXene-fluorohectorite clay heterostructure.

Carbon dioxide (CO2) capture under elevated pressure conditions is of particular relevance for pre-combustion capture and syngas purification processes. Here, we report CO2 adsorption in a nickel-intercalated titanium carbide Ni-Ti3C2Tx MXene-fluorohectorite clay heterostructure, designed to modify the high-pressure adsorption behavior characteristic of pristine MXenes. The heterostructure exhibits a CO2 adsorption capacity of 1.909 mmol g-1 at 50 bar and retains measurable uptake upon pressure release, with 0.602 mmol g-1 remaining at 1 bar after desorption. These results indicate that MXene-clay heterostructures are promising candidates for high-pressure CO2 separation, while also providing a platform for future exploration of CO2 conversion strategies beyond the scope of the present study.