Self-assembled Fe₃O₄ nanoparticles on V₂C MXene for enhanced supercapacitor and microwave absorption applications

Rapid advancements in modern electronic devices necessitate the development of materials that can simultaneously provide efficient energy storage and effective microwave absorption. Herein, a novel composite material was prepared via the self-assembly of Fe₃O₄ nanoparticles on the surface of V₂C MXene. This composite exhibited characteristics suitable for supercapacitor and electromagnetic absorption applications, highlighting the synergistic relationship between energy storage and electromagnetic wave absorption capability. The electrochemical tests revealed that the specific capacity of the V₂C MXene/Fe₃O₄ composite (42.67 mAh·g⁻¹) considerably improved compared with those of the raw materials. The prepared V₂C MXene/Fe₃O₄//V₂C MXene/Fe₃O₄ symmetric supercapacitor (SSC) demonstrated an energy density of 44.8 Wh·L⁻¹, a power density of 959.4 W·L⁻¹, and a capacity retention of 80.14% after 8000 cycles. Moreover, the V₂C MXene/Fe₃O₄ composite exhibited an optimal reflection loss (RL) of −42.4 dB in the Ku band, with an effective absorption bandwidth of 1.9 GHz (14.6–16.5 GHz). This composite material has broad application potential in modern electronic devices owing to its high energy storage capacity and effective electromagnetic wave absorption. This dual functionality improves device performance and offers a compact solution for energy storage and effective microwave absorption.