Search

Potable clean water is in high demand for human life. Numerous technologies like reverse osmosis, flash distillation and electrodialysis are employed and explored to overcome the scarcity of potable water. Last decade has witnessed great attraction of researchers towards membrane capacitive deionization (MCDI) as an alternative technology for water desalination. MCDI holds ability to compete with benchmark desalination techniques as it involves adsorption of ions by porous carbon material on application of low voltage (<1.4 V). Ions are desorbed back into the stream on reversing the potential hence, regenerating the electrodes. Addition of ion exchange membranes enhances the desalination efficiency by reducing the effect of co-ions, which is not possible in traditional capacitive deionization (CDI). Present study aims to synthesize and explore the best fit carbon-based material for MCDI. SPEEK and QPPO polymers were used for CEM and AEM preparation over the porous carbon materials respectively. SEM, XRD and Raman spectroscopy were used to investigate the structural information about carbon materials. Nyquist plots were obtained to analyze diffusive behavior and formation of electrolyte double layer (EDL) on electrode-electrolyte interface. Capacitive behavior of the electrodes was analyzed through cyclic voltammetry (CV) and Galvanostatic charge discharge (GCD). Water desalination performance of membrane coated carbon materials was observed through batch-mode MCDI set-up. Important CDI parameters like salt adsorption capacity (SAC) and specific capacitance were also calculated to evaluate performance of the prepared MCDI electrodes. Among all four synthesized materials, CMGO (carbon spheres modified graphene oxide) reports highest SAC value i.e. 22.5 mg g−1 which suggest CMGO as a promising material for large scale MCDI application. [Display omitted] [ABSTRACT FROM AUTHOR]

Potable clean water is in high demand for human life. Numerous technologies like reverse osmosis, flash distillation and electrodialysis are employed and explored to overcome the scarcity of potable water. Last decade has witnessed great attraction of researchers towards membrane capacitive deionization (MCDI) as an alternative technology for water desalination. MCDI holds ability to compete with benchmark desalination techniques as it involves adsorption of ions by porous carbon material on application of low voltage (<1.4 V). Ions are desorbed back into the stream on reversing the potential hence, regenerating the electrodes. Addition of ion exchange membranes enhances the desalination efficiency by reducing the effect of co-ions, which is not possible in traditional capacitive deionization (CDI). Present study aims to synthesize and explore the best fit carbon-based material for MCDI. SPEEK and QPPO polymers were used for CEM and AEM preparation over the porous carbon materials respectively. SEM, XRD and Raman spectroscopy were used to investigate the structural information about carbon materials. Nyquist plots were obtained to analyze diffusive behavior and formation of electrolyte double layer (EDL) on electrode-electrolyte interface. Capacitive behavior of the electrodes was analyzed through cyclic voltammetry (CV) and Galvanostatic charge discharge (GCD). Water desalination performance of membrane coated carbon materials was observed through batch-mode MCDI set-up. Important CDI parameters like salt adsorption capacity (SAC) and specific capacitance were also calculated to evaluate performance of the prepared MCDI electrodes. Among all four synthesized materials, CMGO (carbon spheres modified graphene oxide) reports highest SAC value i.e. 22.5 mg g−1 which suggest CMGO as a promising material for large scale MCDI application. [Display omitted] [ABSTRACT FROM AUTHOR]

This study delves into the solution-phase incorporation of Ti 3 C 2 T x nanosheets into sulfonated poly(phenylene oxide) (SPPO) to prevail the conventional challenge of distant ionic channels in membranes. A series of membranes incorporating MXene (Ti 3 C 2 T x 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 (I lim = 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. [Display omitted] • Ti 3 C 2 T x nanosheets are incorporated into SPPO to trade-offs of long-range ionic conductivity. • MXe-02 membrane shows excellent electrochemical and physicochemical atributes. • A wide window for fast desalination is possible with 93.52% energy efficiency. • CEMs demonstrates strong antibacterial activity against gram-positive bacteria. [ABSTRACT FROM AUTHOR]