Controllable Patterning of Porous MXene (Ti3C2) by Metal-Assisted Electro-Gelation Method

Since discovered in 2011, transition metal carbides or nitrides (MXenes) have attracted enormous attention due to their unique properties. Morphology regulation strategies assembling 2D MXene sheets into 3D architecture have endowed the as-formed porous MXene with a better performance in various fields. However, the direct patterning strategy for the porous MXene into integration with multifunctional and multichannel electronic devices still needs to be investigated. The metal-assisted electro-gelation method the authors propose can directly generate porous-structured MXene hydrogel with a tunable feature. By electrolyzing the sacrificial metal, the released metal cations initiate the electro-gelation process during which electrostatic interactions occur between cations and the MXene sheets. A high spatial resolution down to micro-meter level is achieved utilizing the method, enabling high-performance hydrogels with more complex architectures. Electronics prepared through this metal-assisted electro-gelation process have shown promising applications of the porous MXene in energy and biochemical sensing fields. Energy storage devices with a capacitance at 33.3 mF cm^?2 and biochemical sensors show prominent current responses towards metabolites (sensitivity of H₂O₂: 165.6  µ A mm ^?1 cm^?2; sensitivity of DA: 212 nA  µ m ^?1 cm^?2), suggesting that the metal-assisted electro-gelation method will become a prospective technique for advanced fabrication of MXene-based devices.