Heteronanoarchitecture of Ti3C2Tx MXene and Amorphous MOF for Exceptional Durability in Electro-Ionic Soft Actuator

Abstract

The assembly of 2D nanosheets with other functional nanomaterials enables the creation of materials with unique property combinations that cannot be achieved in single-phase materials. In particular, a combination of inorganic and organic components provides a pathway to structures offering highly durable ionic and electronic conductivity simultaneously. Here, a controlled growth of amorphous metal–organic framework (aMOF) in the interlayer spaces of Ti₃C₂T_x MXene for enhancing oxidation stability and accelerating fast ion transport is reported. The hydrophilic terminations of MXene provide support for the continuous growth of iron-based aMOF in the available interlayer 2D slits. Effective electronic interactions involving hydrogen bonding, coordination, and esterification in-between the open surfaces of MXene and nanoporous aMOF enhance the electrochemical strength of MXene–aMOF hybrid electrodes and allow the design of extremely durable electro-ionic soft actuators. The MXene–aMOF exhibits a fivefold increment in electroactuation compared to a conventional poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) soft actuator, with robust stability up to 50 000 cycles in open air. Using the MXene–aMOF soft actuator, a deformable morphing surface with reversibly adjustable shapes and patterns is demonstrated.