Fabrication of TiNbC-Mxene-based vanadium dioxide, and polydopamine with sodium alginate 3D-framework for the removal of volatile organic compounds.

In this work, an environmentally friendly method was employed to synthesize a composite hydrogel possessing superior photocatalytic capabilities for removal of volatile organic compound (VOC). TiNbC-MXene were synthesized by exfoliation of TiNbAlC-Maxphase, then TiNbC/VO2 composites were synthesized by water bath heating synthesis method. After that, polydopamine was in situ deposited on the surface of TiNbC/VO2 composites to synthesize TiNbC/VO2@PDA materials. Finally, the TiNbC/VO2@PDA composites were successfully incorporated in sodium alginate (SA) by titration and two-step composite cross-linking process to form TiNbC/VO2@PDA-SA. Its morphological properties and structure were investigated through a series of characterizations. This study further investigates the photocatalytic performance of TiNbC/VO2@PDA-SA for the degradation of six VOCs under UV-light. Toluene, Xylene, and Acetone achieved degradation efficiencies of 88.2 %, 91.6 %, and 94.3 %, respectively, following first-order kinetics. Vinyl Chloride, Isopropyl Alcohol, and Formaldehyde showed removal rates of 86.8 %, 90.3 %, and 92.6 %. A 30-min dark adsorption phase was critical for achieving equilibrium. Moreover, the proposed mechanism and quenching study indicate that hydroxyl and oxygen radicals play a key role in the degradation process. The materials also exhibited outstanding regeneration capability and maintained strong recyclability over ten successive cycles. Overall, the results confirm that TiNbC/VO2@PDA-SA is a highly efficient photocatalyst for VOCs removal.