Green In Situ Fabrication of 3D Porous MoO₃/Ti₃C₂T<i>_x</i> Aerogel Films for Enhanced Supercapacitor Performance without Organic Solvents

Abstract A synergistic modification strategy is adopted to address the restacking issue of MXene nanosheets and enhance the electrochemical performance of MXene‐based electrode materials. 3D porous MoO 3 /Ti 3 C 2 T x aerogel films are successfully prepared via the in‐ situ synthesis of MoO 3 nanobelts on Ti 3 C 2 T x MXene using (NH 4 ) 6 Mo 7 O 24 ·4H 2 O as a molybdenum source. This environmentally friendly method, involving freeze‐drying and carbonization processes, eliminates the need for organic reagents and complex operations like repeated centrifugation and washing. Besides, the construction of a 3D porous structure and the in‐situ introduction of additional pseudocapacitance into MXene as a synergistic modification strategy can effectively improve the restacking of MXene nanosheets, fully expose the electrochemical reaction active sites, and significantly enhance their electrochemical performance. Consequently, the as‐fabricated MoO 3 /Ti 3 C 2 T x aerogel film electrode achieved a specific capacitance of 430.74 F g −1 at 2 mV s −1 , a 42.06% improvement compared to the pure MXene film. It also demonstrated good rate performance at high scan‐rates (200 mV s −1 ) and retained 93.10% of its capacitance after 9000 charge–discharge cycles. The excellent electrochemical performances of high specific capacitance and long‐cycling stability make the MoO 3 /Ti 3 C 2 T x aerogel films promising materials for supercapacitors, and the synergistic modification strategy also provides new insights for fabricating highly efficient electrode materials.