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 Ti3C2Tx 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.