Sediment Recycling from the Preparation of Ti₃C₂T_<i>x</i> for Strain Sensors

Carbides/nitrides (MXenes) have been applied in various fields due to their unique two-dimensional structure and excellent conductivity. However, the sediments from the preparation of MXenes were often discarded without full utilization, which generates huge waste and potential environmental pollution. Here, a strategy of turning waste into treasure is proposed. Sediments from the preparation of Ti3C2Tx have been effectively recycled, and strain sensors have been fabricated based on a 25% Ti3C2Tx-Ti3AlC2/PVA composite film for human motion monitoring. The strain sensor shows a fast response with a gauge factor of 5.53 under the strain of less than 10%. We give a model to explain the operating mechanism of Ti3C2Tx-Ti3AlC2/PVA during the stretching process. The monitoring of human motions on fingers and wrists demonstrates extremely high sensitivity (response time <100 ms). Moreover, the strain sensor exhibits excellent stability. This research opens the door for the future recycling of the sediments generated during the preparation of MXenes.