# Ion‐Confinement‐Assisted Erasure Purifies Oxidized MXene for Reuse

## TL;DR

A new method purifies oxidized MXene by removing insulating oxides, restoring its conductivity and enabling reuse in energy and stealth applications.

## Contribution

The novel erasure-purification strategy enables selective removal of TiO2 from oxidized MXene surfaces, allowing functional recovery and reuse.

## Key findings

- Recovered MXene shows high volumetric capacitance of 1801 F cm−3 and good rate performance.
- Purified MXene exhibits low-frequency electromagnetic attenuation and low infrared emissivity.
- The process achieves ~70% material recovery and is applicable to MXene with various morphologies and oxidation states.

## Abstract

Titanium carbide (Ti3C2T
x
) MXene has attracted broad interest owing to its versatile functional properties. However, its intrinsic instability in aqueous environments drives spontaneous surface oxidation to insulating TiO2, resulting in pronounced performance degradation and posing a major obstacle to practical utilization. Here, we propose an erasure‐purification strategy that selectively targets surface‐derived oxide phases on oxidized MXene. By constructing an ion‐confined interfacial environment followed by a brief acid‐washing step, further oxidation is mitigated while pre‐existing TiO2 is selectively removed. The recovered MXene exhibits restored colloidal stability and can be reassembled into conductive films delivering high volumetric capacitance and favorable rate performance. In addition, the purified MXene demonstrates competitive low‐frequency electromagnetic attenuation and low infrared emissivity in assembled forms. This approach is applicable to MXene with different morphologies and oxidation states, offering a practical and generalizable route for reclaiming and reusing oxidized MXene materials.

An erasure‐purification strategy removes surface‐derived TiO2 from oxidized Ti3C2T
x
MXene by ion‐confinement‐induced interfacial conversion to soluble titanates, followed by brief acid washing. The scalable process enables approximately 70% material recovery, restores electrical conductivity, and recovers functional performance, including high volumetric capacitance (1801 F cm−3), low‐frequency electromagnetic absorption, and competitive infrared stealth.