The Evaluation of Potential Usage of Ti4N3Tx MXene as Interface Layer Catalyst of Bipolar Membrane

Abstract

Modifications to the membrane and interface layer are crucial for enhancing bipolar membrane (BPM) performance. This study investigates the potential use of Ti₄N₃T_x in the BPM interface layer. Ti₄N₃Tₓ was synthesized from the Ti₄AlN₃ MAX phase via salt melting, and its successful synthesis was confirmed through X-ray diffraction, X-ray photoelectron spectroscopy, thermogravimetric analysis, atomic force microscopy, and water contact angle analyses. Incorporating Ti₄N₃T_x significantly increased BPM hydrophilicity. The water uptake capacity of BPM-1/PS (without Ti₄N₃Tₓ) and BPM-3/PS (containing 0.4 wt% Ti₄N₃Tₓ in polymer suspensions) was 10% and 17%, respectively. The Young’s modulus of BPM-1/PS was 634 MPa, whereas BPM-2/PS (with 0.2 wt% Ti₄N₃Tₓ in polymer suspension) exhibited 963 MPa, enhancing BPM stability. However, increasing the MXene content raised electrical resistance from 0.26 Ω·cm² (BPM-1/PS) to 2.00 Ω·cm². Compared to conventional BPM interface materials, such as metal oxides and carbon-based nanomaterials, Ti₄N₃Tₓ MXene offers a unique combination of tunable hydrophilicity, mechanical reinforcement, and surface charge modulation, providing an alternative strategy for optimizing BPM performance. These findings suggest that MXene-modified BPMs are promising for electrochemical water splitting, electrodialysis, and redox flow batteries, as well as wastewater treatment and energy storage applications.