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Solar-driven interfacial evaporation is recognized as an energy-efficient and sustainable approach to combat the global freshwater crisis, particularly in rural areas where continuous energy inputs are limited. Additionally, these regions often lack effective sterilization methods for their water sources. By incorporating photothermal materials with inherent antibacterial properties, water purification can be enhanced without relying on external sterilization steps. Herein, we designed a multi-functional photothermal (MFP) evaporator based on a Cu dendrite@ CuO with abundant nanowires via a template-free method for solar-thermal clean water production. Compared to flat-type structures, the MPF evaporator with its dendritic architecture not only exhibits efficient photon absorption but also expands the evaporation area by over sevenfold, facilitating enhanced water evaporation with an efficient pathway for water transfer. Under 1 kW m−2, the MFP evaporator achieves an impressive evaporation rate of 1.40 kg m−2 h−1 and an efficiency of 87.8 %. Furthermore, the MFP evaporator demonstrates remarkable antibacterial capabilities, effectively inhibiting bacterial growth in raw water by damaging bacterial cell walls. Hence, the as-prepared MFP evaporator exhibits tremendous potential as an innovative system for solar-driven interfacial water evaporation and purification. We proposed a multi-functional photothermal (MFP) evaporator for solar-thermal clean water production which realized a photothermal evaporation temperature of 40.6 °C and an evaporation rate of >1.40 kg m−2 h−1 via ∼ 87.8 % solar conversion under 1 sunlight illumination, originating from the large photo-thermal evaporation area, narrow heat conduction path, and efficient water transfer. Besides, the MFP evaporator was fabricated through a simple process of low cost and can be connected together to form large-scale floating networks for water evaporation. Moreover, the MFP evaporator possessed a great antibacterial ability, inhibiting the growth of bacteria in raw water by destroying the cell wall of bacteria. Thus, the as-prepared MFP evaporator has great potential serves as a novel system for implementing solar-driven interfacial water evaporation and water purification. [Display omitted] • A multi-functional photothermal evaporator was designed for solar water evaporation. • Enhanced light trapping and large evaporation area contributed an excellent evaporator. • The MFP evaporator with inherent antibacterial properties (rejection rate exceeded 99.9 %). • The conversion efficiency of the setup reaches as high as 87.8 % under 1 sun. • A low-cost and well-controllable fabrication process enables for large-scale applications. [ABSTRACT FROM AUTHOR]

The physicochemical and structural properties of the AMX (homogeneous AEM), AMA (semi-homogeneous AEM) and HAEM (heterogeneous AEM) were characterized systematically to examine their effects on membrane fouling from sodium dodecyl sulfate (SDS) in electrodialysis. Results demonstrated that the fouling of three AEMs was closely related to their membrane structure, and the denser membrane structure caused more SDS accumulated on the membrane surface to make the severer membrane fouling. The existence of SDS in the dilute solution caused the desalination rate of AMX, AMA and HAEM decreased by 42.3%, 15.3% and 9.2%, respectively. Different fouling layer was formed on the surface of AMX and AMA except HAEM, which was demonstrated firstly by element mapping of membrane cross-section. Electrochemical impedance spectroscopy (EIS) suggested the ionic migration through the fouled AMX was restricted completely, different from the transmembrane migration of partial ions through the fouled AMA and HAEM. Compared with the fouled AMA and HAEM, the performance of the fouled AMX caused by SDS was more difficult to be recovered due to its denser membrane structure. [ABSTRACT FROM AUTHOR]

One of the most widely used CDI processes is flow electrode capacitive deionization (FCDI), which is preferred over conventional CDI with static electrode due to its continuous treatment of high-salt wastewater and ability to scale production. However, the discontinuous charge transport network in flow electrodes restricts the improvement of desalination performance. In this study, we prepared nickel hexacyanoferrate and carbon nanotubes composites (NiHCF@CNTs) by a simple ball-milling method and constructed an asymmetric FCDI (AFCDI) system using NiHCF@CNTs and AC as flow cathode and anode, respectively. Then the desalination performance of AFCDI was examined and compared with that of symmetric FCDI system using AC as both flow electrodes under different conditions. The stability was also investigated by a 20-cycle operation test. It was found that AFCDI system showed higher average salt removal rate and lower energy consumption compared with FCDI, owing to the enhancement of charge transport resulting from the couple of high specific capacitance of NiHCF and excellent electrical conductivity of CNTs. Moreover, AFCDI system has stable desalination performance in continuous operation. These results indicate that compositing Faradic materials and CNTs is an effective strategy for improving desalination performance of FCDI. [Display omitted] • NiHCF@CNTs composite was prepared by a simple ball-milling method. • AFCDI was constructed with NiHCF@CNTs as cathode and AC as anode. • Composite of NiHCF and CNTs can strengthen charge transport of flow electrode. • AFCDI showed better desalination performance than FCDI-AC. • AFCDI has stable and efficient desalination performance in continuous operation. [ABSTRACT FROM AUTHOR]

Flow-electrode capacitive deionization (FCDI) provides the opportunity for continuous desalination operation of high concentration saline water. In this study, we firstly report the application of a battery material (a Prussian blue analogue, copper hexacyanoferrate, CuHCF) as flowable electrode in FCDI system, where it is coupled with activated carbon (AC). Its desalination performance under different voltage is evaluated when dealing with 10 g L−1 NaCl solution. Results show that the salt removal rate and salt removal efficiency of the designed FCDI is enhanced as increasing in applied voltage from 1.2 to 2.8 V. Moreover, benefiting from the high capacity of CuHCF material, the novel FCDI based on CuHCF-AC pair shows superiority over conventional FCDI with AC-AC pair when operates at high voltage over 2.0 V (e.g. salt removal rate of 0.12 vs. 0.11 mg cm−2 min−1, salt removal efficiency of ~91 vs. 84% and current efficiency of ~96 vs. 95% at 2.8 V), even though the pH of the concentrated water changes more significantly. The results indicate that FCDI based on CuHCF-AC electrode pair is effective in dealing with high saline water at high voltage. Other sodium ion intercalation material may also be applied in FCDI. Unlabelled Image • Copper hexacyanoferrate (CuHCF) is firstly used as flowable electrode in FCDI. • FCDI with CuHCF-AC pair works better than that with AC-AC pair at high voltage. • Desalination performance in FCDI was enhanced as increase in voltage from 1.2 to 2.8 V. [ABSTRACT FROM AUTHOR]

A new strategy combining electrodeposition with co-deposition modification was proposed to in-situ construct a stable antifouling modified layer on the AEM surface without disassembling the membrane stack. Specifically, dopamine (DA) was introduced into the electrodeposition process of poly (sodium 4-styrene sulfonate) (PSS) to co-deposit onto the AEM surface, in which the polymerization reaction could promote by supporting electrolyte (NaCl). The formation of cross-linked structure and π-π stacking effect during in-situ modification could ensure the stability of the modified layer. The in-situ modified AEM had a negatively charged and more hydrophilic surface, significantly improving the antifouling performance against organic matter (sodium dodecylbenzene sulfonate) without affecting desalination performance. Moreover, it still had excellent antifouling properties after 96 h neutral rinsing. This work provided a novel approach for preventing organic fouling of AEM in ED process through surface modification. [Display omitted] • AEM was in-situ modified by combining electrodeposition with co-deposition. • The laws of key operating parameters on the modification effect were found out. • NaCl help to promote polymerization reaction which improve modified layer stability. • In-situ modified AEM exhibited good antifouling ability and stability. [ABSTRACT FROM AUTHOR]

Ordered mesoporous carbons (OMCs) with various pore properties and oxygen-containing functional groups were obtained by changing preparation conditions and thermal or chemical modification after preparation. The modification hardly changed the pore structure of OMCs but did tailor surface properties. Desalination performance of capacitive deionization (CDI) by OMCs was investigated during 50 continuous cyclic adsorption/desorption experiments using a 500 mg/L NaCl solution and an applied potential of 1.2 V. The results showed pronounced degradation in the desalination performance for all materials as the cycle number increased, and an inversion in conductivity appeared at the beginning of the adsorption or desorption stage after several cycles. The surface properties are important for initial desalination, with the material with moderate oxygen functional groups displaying the largest desalination capacity, rate and charge efficiency. However, these groups had a negligible effect on the long-term desalination stability. The material which had a very small surface area and pore size underwent the most remarkable performance degradation, and large surface area and pore diameter were more favorable towards long-term stability. The deterioration in CDI performance was attributed partially to the decrease in surface area and mostly to an increase in oxygen functional groups on the electrodes, especially the anodes. [ABSTRACT FROM AUTHOR]

Flow electrode capacitive deionization (FCDI) has attracted growing attention for the treatment of high-concentration saline water and continuous operation, but the mechanism responsible for the separation of ions has so far received minimal attention. In this study, an asymmetric FCDI (AFCDI) was assembled with nickel hexacyanoferrate (NiHCF) as cathode and activated carbon (AC) as anode. Its desalination performance and distribution of the removed ions were investigated and compared with FCDI using AC as both cathode and anode. Results showed better desalination performance for AFCDI than FCDI at high applied voltages of 2.4 and 2.8 V. The removed ions were adsorbed by active materials (capacitance contribution) and existed in the electrode electrolyte (charge neutralization contribution). However, the contribution of capacitance and charge neutralization was significantly different between NiHCF electrode and AC electrode. When NiHCF was used as electrode, capacitance contribution dominated the removal of sodium and more than 80% sodium was adsorbed by NiHCF at applied voltages of 1.2–2.8 V. On the contrary, the removed ions mainly existed in electrode solution when AC was used as electrode and charge neutralization contributed to about 80% of removed ions at 2.8 V. These results clarify the mechanism of ions removal in FCDI. [Display omitted] • AFCDI was assembled with NiHCF as cathode and AC as anode. • AFCDI showed better desalination performance than FCDI under higher voltage. • Both charge neutralization and capacitance contributed to the removal of ions. • Capacitance contribution dominated the removal of sodium in AFCDI. • Removed ions mainly existed in electrode solution in FCDI. [ABSTRACT FROM AUTHOR]