High capture capacity of CO₂ in a nickel intercalated Ti₃C₂T_x 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-Ti₃C₂T_x 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.