Mixed‐Sized Graphene Oxides Induce Highly Densified MXene‐Based Films with High Conductivity and Exceptional Stability

Abstract MXene‐based films are prevalent in a variety of applications owing to their advantages such as high metallic conductivity and unique mechanical properties. However, the stability issue is the primary drawback that greatly constrains their practical applications. In this study, an MXene‐based film featuring excellent stability, high conductivity, and remarkable flexibility is designed and fabricated. It is worth noting that this film, denoted as MX‐GO(l/s), is afforded via the rational combination of mixed‐sized graphene oxide (GO) nanosheets with MXene layers. Comprehensive explorations reveal that compact and highly dense structures are formed in MX‐GO(l/s), which is ascribed to the synergistic effect of both electrostatic repulsion and intercalation. Furthermore, the exceptional stability of MX‐GO(l/s) is demonstrated by the high retention rates in conductivity under a 90‐day exposure in air and a 12‐h immersion in seawater, which are determined as 98% and 92%, respectively. The radio frequency identification (RFID) antenna based on MX‐GO(l/s) is fabricated and evaluated, showing great potential in practical applications. This study paves the way for the further development of MXene‐based films via controlled addition of the second phase, which is beneficial for their broad application prospects.