Synergistic incorporation of Ti3C2Tx with sulfonated poly(phenylene oxide) membranes: Unravelling multifaceted advancements in physicochemical, electrochemical, and antibacterial domains for enhanced electrodialytic desalination

Abstract

This study delves into the solution-phase incorporation of Ti3C2Tx nanosheets into sulfonated poly(phenylene oxide) (SPPO) to prevail the conventional challenge of distant ionic channels in membranes. A series of membranes incorporating MXene (Ti3C2Tx nanosheets) at varying weight percentages (1 wt%, 2 wt%, and 5 wt%) underwent meticulous scrutiny of their physicochemical and electrochemical attributes. Among this series, MXe-02 emerged as particularly noteworthy, showing remarkable water sorption (WS= 43.8%), ion exchange capacity (IEC: 1.65 ± 0.05 meqg−1), and ionic conductivity (IC: 2.83×10−2 S cm−1), coupled with minimal dimensional change of 8.57% compared to its pristine counterpart, SPPO-B (WS=35.70%, IEC: 1.03±0.05 meqg−1, IC: 1.98×10–2 S cm−1). Advanced analytical techniques such as atomic force microscopy (AFM) and field emission-scanning electron microscopy (FE-SEM) provided insights into hydrophilic-hydrophobic phase separation, ionic domain clustering, and membrane surface attributes pivotal for enhancing electrochemical properties. Beyond optimal concentrations (>2 wt%), a significant composite-agglomeration effect hindered further advancements in physicochemical and electrochemical aspects, as verified by zeta potential measurements. The optimized MXe-02 membrane boasted a notable transport number of 0.89 with a substantial limiting current density (Ilim = 45 mA cm−2), offering a wide window for swift electrodialytic desalination. Moreover, MXe-02 membranes demonstrated an energy consumption of 0.98 kWh kg−1 and 93.52% energy efficiency, affirming their efficacy for brackish water desalination. Antibacterial properties were evaluated against Escherichia coli and Staphylococcus aureus, revealing MXe-02 and MXe-05's distinct zones of inhibition against S. aureus, highlighting their excellent antibacterial efficacy against Gram-positive bacteria. This comprehensive study shows the intricate interplay of MXene-incorporated membranes, offering valuable insights for advancing electrochemical and antibacterial performance in water desalination.