High Ion Research Articles

A novel ion-responsive hydrogel based on quaternized chitosan and hydroxyethyl cellulose for high efficient chloride ion adsorption

Chloride removal is crucial for industrial wastewater discharge, seawater purification and concrete structure durability. In this study, a novel hydrogel with excellent chloride adsorption property was prepared and the adsorption capacity in relation to external pH and other ions was evaluated. The hydrogel was synthesized using a one-pot method with quaternized chitosan (HACC), hydroxyethyl cellulose (HEC), and carboxymethyl chitosan (CMC) as monomers. By adjusting the material compositions, we effectively modulated the microstructure and charge characteristics of hydrogel, achieving a balanced swelling ratio and optimal adsorption performance. The optimal process conditions were identified as 25 °C and a chloride ion concentration of 40 mmol L−1, achieving a maximum adsorption capacity of 1080 mg g−1. Isotherm modeling showed that the adsorption fits well with the Freundlich isotherm, suggesting multilayer adsorption. The quaternary ammonium groups serve as fixed positive charge sites or active adsorption sites, enabling the hydrogel to efficiently adsorb anions through the synergistic effects of electrostatic interactions, physical adsorption, and amino protonation. The varied adsorption capacities of quaternary ammonium groups for different anions give rise to competitive adsorption phenomena among them. The incorporation of silver ions into the hydrogel greatly enhances its selective adsorption of chloride ions through chemical combination. This work presents a comprehensive strategy for designing a novel hydrogel with exceptional adsorption properties specifically tailored for chloride ions.

Redistribution of Nb and other alloying elements in Nb-doped Zr alloy under high dose ion irradiation

ABSTRACT To understand the microstructural changes in Nb-doped zirconium alloy cladding at high irradiation doses, the Mitsubishi Developed Alloy (MDA) cladding was ion- irradiated up to 40 dpa at 400 ◦ C and the distribution of alloying elements was in- vestigated using atom probe tomography (APT) and scanning transmission electron microscopy and energy dispersive X-ray spectroscopy (STEM-EDS). APT analysis revealed two types of Nb nanoclusters with different Nb contents after the ion irradia- tion. The Nb concentration in the matrix decreased significantly with ion irradiation up to 10 dpa and then decreased slowly to 40 dpa. STEM-EDS analysis estimated that the secondary phase precipitates (SPPs) of Zr(Fe,Cr,Nb)2 and Zr(Fe,Cr)2 were formed before the ion irradiation. Although Fe, Cr, and Nb were dissolved from the SPPs during the ion irradiation, these alloying elements still remained in the SPPs after 40 dpa irradiation. Other Fe-Cr nanoclusters, Nb-rich phase, and Fe-rich phase were also formed during the ion irradiation. These radiation-induced precip- itates were observed until after 40 dpa irradiation and were expected to be stable under irradiation conditions.

Single ion mobility monitoring (SIM2) stitching method for high-throughput and high ion mobility resolution chiral analysis

Chiral analysis is of high interest in many fields such as chemistry, pharmaceuticals and metabolomics. Mass spectrometry and ion mobility spectrometry are useful analytical tools, although they cannot be used as stand-alone methods. Here, we propose an efficient strategy for the enantiomer characterization of amino acids (AAs) using non-covalent copper complexes. A single ion mobility monitoring (SIM2) method was applied on a TIMS-ToF mass spectrometer to maximize the detection and mobility separation of isomers. Almost all of the 19 pairs of proteinogenic AA enantiomers could be separated with at least one combination with the chiral references L-Phe and L-Pro. Furthermore, we extended the targeted SIM2 method by stitching several mobility ranges, in order to be able to analyze complex mixtures in a single acquisition while maintaining high mobility resolution. Most of the enantiomeric pairs of AAs separated with the SIM2 method were also detected with this approach. The SIM2 stitching method thus opens the way to a more comprehensive chiral analysis with TIMS-ToF instruments.Graphical

Ion-selective supramolecular membrane with pH-regulated smart nanochannels for lithium extraction

Tunable gating ion-conducting membranes with high water permeability and precise ion selectivity remain urgently demanded in smart nanofiltration for efficient lithium extraction. Herein, inspired by the filtration function of protein channels, we report a smart and high-performance supramolecular membrane constructed via coordination between quaternary ammonium ligands (m-phenylenediamine/polyethyleneimine) and metal ion center (Cu2+). The pore architecture of the supramolecular membrane is dynamic and can be switched by applying pH stimulus, where coordinated interchain expands when exposed to acidic operating conditions and induces concomitantly reinforced electrostatic exclusion due to enhanced local charge density. The tunable gating regularity enables operando modulation of precise ionic separation in situ. The resulting membrane exhibits significantly enhanced water permeance (19.8 L m−2 h−1·bar−1) and simultaneously promoted Li+/Mg2+ selectivity (RMg2+ = 96.4 %), surpassing typical trade-off between permeability and selectivity at pH 3 condition. This study demonstrates the amazing capability of environmental-responsive regulation of membrane pore-channel structure, and provides inspiration for engineering advanced supramolecular membranes for lithium extraction and beyond.

Antimicrobial potential and protein binding affinity of a hybrid ternary nanocomposite matrix: Zinc oxide functionalization with poly(vinyl alcohol)-sulphonated graphene oxide-poly pyrrole

The present study focuses on the application of a ternary PVA/sGO/ZnO-NP/PP nanocomposite as an antibacterial and antifungal agent. The process involved utilizing a solution casting technique to fabricate the inorganic–organic blend material, where 4-sulfophthalic acid (SPTA) was used in the sulfonation of graphitic oxide (GO) sheets. The amalgamation of polyvinyl alcohol polymer (PVA) and sulphonated GO (sGO) was achieved through a chemical oxidation polymerization process carried out in a water-based environment. This process developed a PVA/sGO film, in which zinc oxide nanoparticles (ZnO-NP) and pyrrole monomers were introduced. The PVA/sGO film served as the initial stage for the in-situ deposition and formation of polypyrrole (PP), leading to the fabrication of PVA/sGO/ZnO-NP/PP membrane. The structure was stabilized by hydrogen bonding and electrostatic interactions between the components, while SPTA acted as a cross-linker and a sulphonating agent. The Fourier transform infrared (FTIR) spectra of the quad-component composite unraveled the presence of distinctive functional groups, including PVA, sGO, PP, and Zn-O bands. The UV–visible spectra of PVA/sGO/ZnO-NP/PP nanocomposite membrane revealed a peak in the UV-B region, while in-depth X-ray diffraction (XRD) analyses provided strong evidence of its amorphous nature. The scanning electron microscopy (SEM) image showed that the top surface of the organic film was adorned with PP polymeric chains. The membrane exhibited great water retention capabilities due to its high ion exchange capacity (IEC) value.Additionally, the minimal water loss observed underscores its extended shelf life. Due to their inherent hydrophilic properties, the ternary nanocomposite membranes exhibited enhanced hydrophilicity, porosity, zeta potential, and water uptake. The BET and BJH analyses revealed that PVA/sGO/ZnO-NP/PP nanocomposites had a substantial surface area. Remarkably, the nanocomposite membrane exhibited significantly improved antimicrobial efficacy against bacteria and fungi. The type of interactions between Human serum lysozyme (HSL) and nanocomposite at the molecular level was studied through fluorescence spectroscopy. Stern-Volmer plot revealed the occurrence of both static and dynamic quenching. However, the precise mechanisms underlying the antimicrobial and protein binding (HSL) studies of PVA/sGO/ZnO-NP/PP-based nanocomposites require further investigation.

Perovskite intermediate phase FAPbBr3·DMSO assisted in-situ growth of FAPbBr3 polycrystalline wafer for X-ray detection and imaging

Polycrystalline perovskite wafers featured in customizable in dimensions and thickness, represent a frontier in mass production of X-ray detectors. Nevertheless, inherent low crystallinity, elevated defect density, and grain boundaries in polycrystalline wafers typically impair the detection performance. Herein, a novel hot-pressing approach employing the perovskite intermediate phase FAPbBr3·DMSO was demonstrated to improve the quality and X-ray detection performance of polycrystalline perovskite wafers. The in-situ growth of FAPbBr3 wafers were promoted via dimethyl sulfoxide (DMSO) vapor released from the decomposition of FAPbBr3·DMSO phase during the hot-pressing process, resulting in compact morphology, large grain size, superior crystallinity and diminished defect density. The resulted wafers exhibit a high ion activation energy (Ea) of 0.45 eV and a substantial mobility-lifetime product (μτ) of 7.41 × 10−4 cm2 V−1. These advancements equip FAPbBr3 wafer-based detectors with remarkable sensitivity of 3694.6 μC Gyair−1 cm−2, low detection limit (LoD) of 43.8 nGyair s−1, and stable operational performance, comparable to that of single-crystal alternatives. Moreover, the detectors exhibit exceptional X-ray imaging capabilities with a spatial resolution of 4.41 lp mm−1. Thus, the thermally induced decomposition characteristic of perovskite intermediate phase presents a novel avenue for the amelioration of polycrystalline perovskite wafers, heralding a leap forward in X-ray detection performance.

The flexibility of pre-embedding Na+ and PO43- in layered V2O5 for high capacity and stability zinc ion batteries

To address the challenge of balancing high conductivity, capacity, and long-cycle stability in V2O5 cathode materials for aqueous zinc-ion batteries, we introduce an innovative strategy of co-embedding cations and anions into the layered V2O5 structure. We synthesized Na and P co-embedded layered V2O5 materials and systematically investigated their morphological structure, elemental valence, and electrochemical properties using X-ray diffraction, scanning electron microscopy, Fourier infrared spectroscopy, X-ray photoelectron spectroscopy, and electrochemical characterization. The synthesized material demonstrated a high capacity of 357.8 mAh·g−1 at 0.2 A·g−1 and a remarkable capacity retention of 107.7 % after 2000 cycles at 4.0 A·g−1. These results highlight the synergistic effect of co-embedded ions and structured water, offering new insights into the insertion/extraction dynamics of pre-embedded ions, structured water, and zinc ions in layered V2O5.

Detection of dual-methylated BRCA1/BRCA2 cell-free DNA for ovarian cancer on an aptamer-based integrated microfluidic system

A new screening strategy has been developed to select nucleic acid aptamer probes with an “in vivo-like” systematic evolution of ligands by exponential enrichment (SELEX) process featuring positive, negative selection and in vivo-like selection steps. One methylation-specific aptamer with high affinity and specificity was selected and it could capture methylated cell-free DNA (cfDNA) from unfiltered blood of ovarian cancer (OvCa) patients. This aptamer was conjugated onto magnetic beads and integrated into a new microfluidic chip for rapid and automatic detection and quantification of two prevalent methylated tumor suppressor genes, breast cancer type 1 and 2 susceptibility protein (BRCA 1/2), in the molecular profile of OvCa. The assay was conducted under physiological conditions that mimic the microenvironment of cancer patients at 25–37 °C, with a low pH value (5.5) and/or high blood ion levels, without requiring additional sample preparation steps. The results of this study could be extrapolated to the direct detection of methylated cfDNA at levels as low as 1 pM in blood or plasma. Not only was DNA methylation observed in OvCa patients, but it was also detected in many other types of cancer; it is therefore considered an important factor in carcinogenesis. Hence, it is inferred that this screened aptamer should not only be used for OvCa diagnosis but also for multiple cancer epigenetic detection and drug development research in the future.

Self‐Supporting Solid Electrolyte Based on Supramolecular Interaction for Stable Li Metal Batteries

AbstractLi metal batteries based on solid polymer electrolytes offer the benefits of high energy density and safety, as well as extended cycling life, making them an excellent candidate for the next‐generation battery system. However, current solid polymer electrolytes still suffer from low ion conductivity and Li+ transfer number, which seriously restricts its practical application. Herein, a self‐supporting composite solid polymer electrolyte was prepared, where phenolic resin rich in hydroxyl groups (BR) and polyethylene oxide (PEO) are mixed evenly and poured onto a cellulose membrane in one step. In such an electrolyte, PEO and BR combine to form intermolecular hydrogen bonds, lowering the crystallinity of PEO and increasing the Li+ transfer number. Lastly, the obtained solid electrolytes exhibited a high ion conductivity (1.1×10−4 S cm−1) and Li+ transfer number (0.53), as well as improved electrochemical window. Consequently, Li || Li symmetrical cells can run stably for more than 700 h at 0.1 mA cm−2/0.25 mAh cm−2. And full cells with LiFePO4 cathode can also demonstrate high discharge capacity of 152.12 mAh g−1 and rate performance. We believe that such a design based on supramolecular interaction offer a new avenue to advanced solid polymer electrolytes.

Dual functional composite solid electrolyte constructed by double-layer sulfonated polyethersulfone (SPES)/poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofiber membrane in high-performance all-solid-state lithium metal batteries

The successful implementation of polymer electrolytes in next-generation all-solid-state lithium metal batteries (ASSLMBs) is impeded by their low ion conductivity and weak resistance to lithium dendrites. Herein, a composite solid electrolyte (D-SPES-PH-PEO) with dual reinforcement effects is obtained by combining PEO matrix with a double-layer sulfonated polyethersulfone (SPES)-poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofiber membrane. The SPES nanofiber membrane acts as a hopping site for ion transport by utilizing the electronegativity and Coulombic force of its own –SO3H groups, reducing the energy barrier of the D-SPES-PH-PEO electrolyte. Profiting from the existence of C-F bond, PVDF-HFP nanofiber membrane specializes in generating a protective SEI layer on the lithium anode. Moreover, such a functional membrane not only effectually constructs a three-dimensional ion transport channel by fabricating ion conductive substructures, but also enhances the mechanical strength of the electrolyte. Consequently, the D-SPES-PH-PEO electrolyte is equipped with a high ion conductivity of 7.41 × 10−5 S cm−1 at 30 °C and high tensile strength of 8 MPa. Furthermore, Li/Li symmetric battery incorporating D-SPES-PH-PEO electrolyte enables a stable cycle for 2500 h at 0.2 mAh cm−2. The D-SPES-PH-PEO electrolyte represents outstanding compatibility with LiFePO4 and high-voltage LiNi0.8Mn0.1Co0.1O2 (NMC811) electrodes. Especially, the LiFePO4/D-SPES-PH-PEO/Li pouch cell indicates an initial specific capacity of 146.7 mAh g−1 and the NMC811/D-SPES-PH-PEO/Li pouch cell reaches a maximum capacity of 178.5 mAh g−1. This study emphasizes the importance of double reinforcement of ion conduction and anode protection on solid electrolytes.

Incorporation of Ionic Conductive Polymers into Sulfide Electrolyte‐Based Solid‐State Batteries to Enhance Electrochemical Stability and Cycle Life

Sulfide‐based inorganic solid electrolytes are promising materials for high‐performance safe solid‐state batteries. The high ion conductivity, mechanical characteristics, and good processability of sulfide‐based inorganic solid electrolytes are desirable properties for realizing high‐performance safe solid‐state batteries by replacing conventional liquid electrolytes. However, the low chemical and electrochemical stability of sulfide‐based inorganic solid electrolytes hinder the commercialization of sulfide‐based safe solid‐state batteries. Particularly, the instability of sulfide‐based inorganic solid electrolytes is intensified in the cathode, comprising various materials. In this study, carbonate‐based ionic conductive polymers are introduced to the cathode to protect cathode materials and suppress the reactivity of sulfide electrolytes. Several instruments, including electrochemical spectroscopy, X‐ray photoelectron spectroscopy, and scanning electron microscopy, confirm the chemical and electrochemical stability of the polymer electrolytes in contact with sulfide‐based inorganic solid electrolytes. Sulfide‐based solid‐state cells show stable electrochemical performance over 100 cycles when the ionic conductive polymers were applied to the cathode.

Iodine- and nitrogen-CO-doped carbon flower materials for the anode electrode of lithium-ion batteries

As green anode materials with wide distribution, controllable cost, and diversified structure, carbon materials have received more attention. In this paper, iodine- and nitrogen-co-doped carbon flower materials were prepared. The flower-like structure of the material ensures the rapid diffusion of lithium ions, and the synergistic effect of iodine and nitrogen atoms improves the pore size distribution, the conductivity and the active sites of carbon materials realizing the high ion storage and the fast charge diffusion. As the anode material of lithium-ion batteries, the iodine- and nitrogen-co-doped carbon flower could have the capacitance of 410 mAh g[Formula: see text] at the current density of 0.1 A g[Formula: see text] after 150 cycles and 181 mAh g[Formula: see text] at the high current density of 2.0 A g[Formula: see text] after 1000 cycles. The results of electrochemical impedance spectroscopy, kinetics, and GITT show this material has fast charge transport kinetics and excellent rate performance.

Non-flammable polymer electrolyte with fast ion conductivity for high-safety Li batteries

The safety and ionic conductivity of solid polymer electrolytes have hindered their large-scale application. Tetrabromobisphenol A (TBBA) is regarded as an efficient flame retardant for polymers. However, the -OH group of TBBA is active during electrochemical process and results in the sacrifice of capacity in battery cycling. Herein, a new organic filler, TBBA-dichlorobutane (TD) is generated by replacing the H of -OH in TBBA using the 1,4-dichlorobutane through copolymerization modification. The electrochemical stability of TD has been improved, which facilitates the generation of the solid electrolyte interphase (SEI) layer of LiBr, improving interface ionic conductivity. Meanwhile, the addition of TD significantly reduces the crystallinity of polyacrylonitrile (PAN), improving the ionic conductivity of the electrolyte. Furthermore, the electrochemical mechanism has been characterized by in-situ Raman and Fourier transform infrared (FT-IR) spectra, revealing the high stability and fast ion transfer ability of electrolytes. From the theoretical calculation (density functional theory (DFT), COMSOL, and molecular dynamics (MD)), the priority combination between lithium-ion and the bromine in PAN-TD (P-TD), as well as uniform lithium-ion flux, can be certified. Therefore, the LiFePO4//Li battery exhibits a specific capacity of 157 mA h g−1 at 0.5 C and maintains 154 mA h g−1 after 100 cycles. At the same time, the safety properties have been improved by the formation of the carbon layer and the capture of free radicals through bromine, exhibiting an oxygen index as high as 29 %.

Tailoring Stress-Relieved Structure for SnSe Toward High Performance Potassium Ion Batteries.

Metal chalcogenides as an ideal family of anode materials demonstrate a high theoretical specific capacity for potassium ion batteries (PIBs), but the huge volume variance and poor cyclic stability hinder their practical applications. In this study, a design of a stress self-adaptive structure with ultrafine SnSe nanoparticles embedded in carbon nanofiber (SnSe@CNF) via the electrospinning technology is presented. Such an architecture delivers a record high specific capacity (272 mAh g-1 at 50mA g-1) and high-rate performance (125 mAh g-1 at 1 A g-1) as a PIB anode. It is decoded that the fundamental understanding for this great performance is that the ultrafine SnSe particles enhance the full utilization of the active material and achieve stress relief as the stored strain energy from cycling is insufficient to drive crack propagation and thus alleviates the intrinsic chemo-mechanical degradation of metal chalcogenides.

On direct-current magnetron sputtering at industrial conditions with high ionization fraction of sputtered species

In the industry, there is a preference for robust and technologically straightforward solutions that can deliver desired products at reasonable costs. This study introduces a reliable, robust, and cost-effective ion-assisted thin film growth technique called moving focused magnetic field magnetron sputtering. At the core of this technology lies the generation of dense plasma within a small area of the target and the controlled movement of this plasma across the entire target surface. The deposition process, powered by a direct current generator, behaves similarly to high-power impulse magnetron sputtering and yields coatings with properties comparable to those produced by this method. Notably, this study marks the first application of an ion meter to measure the ionized metal flux fraction of sputtered titanium at industrial conditions, revealing values of up to 34% measured at the substrate position.

A systematic study of solvation structure of asymmetric lithium salts in water

Aqueous electrolytes are promising in large-scale energy storage applications due to intrinsic low toxicity, non-flammability, high ion conductivity, and low cost. However, pure water’s narrow electrochemical stability window (ESW) limits the energy density of aqueous rechargeable batteries. Water-in-salt electrolytes (WiSE) proposal has expanded the ESW to over 3 V by changing electrolyte solvation structure. The limited solubility and WIS electrolyte crystallization have been persistent concerns for imide-based lithium salts. Asymmetric lithium salts compensate for the above flaws. However, studying the solvation structure of asymmetric salt aqueous electrolytes is rare. Here, we applied small-angle x-ray scattering (SAXS) and Raman spectroscope to reveal the solvation structure of imide-based asymmetric lithium salts. The SAXS spectra show the blue shifts of the lower q peak with decreased intensity as the increasing of concentration, indicating a decrease in the average distance between solvated anions. Significantly, an exponential decrease in the d-spacing as a function of concentration was observed. In addition, we also applied the Raman spectroscopy technique to study the evolutions of solvent-separated ion pairs (SSIPs), contacted ion pairs (CIPs), and aggregate ions (AGGs) in the solvation structure of asymmetric salt solutions.

Angstrom‐scale channels with versatile ion‐membrane interactions enabling precise ion separation via electrodialysis

AbstractIn nature, efficient and selective ion transport is facilitated by ion‐conductive channels in cell membranes; these channels reveal an architectural design with specialized functionality. Drawing inspiration from this, mechanistic insights into the angstrom‐scale‐channel membrane composed of ionic‐crosslinked polybenzimidazole and sulfonated poly(ether ether ketone), exhibiting functional differentiation and efficient ion‐sieving properties are presented. Nanochannels allow for strong hydrogen‐bonding interactions with hydrated ions of higher polarity, while rendering significant electrostatic charge effects that impede the transition of multivalent ions by compressing effective passageways. Both hydrogen bonding and electrostatic interactions synergistically result in high selectivity for monovalent ions over multivalent ions because the latter requires overcoming higher energy barriers for transport compared with the former, thereby causing varying extents of ion dehydration within the nanochannels. The resulting membrane achieves a high monovalent ion permeation rate of 1.35 mol m−2 h−1 with a high mono/multivalent ion selectivity of 56.5 for K+/Mg2+ and 286 for K+/Al3+.

Transformation behavior of hazardous jarosite into recyclable hematite in a solution with high concentrations of K+ and Na+

Iron in the leaching solution with high K+ and Na+ concentrations was usually precipitated as the typical hazardous and toxic jarosite residues. However, this method of treatment has been greatly restricted by increasingly strict environmental regulations. Here we propose that iron can be precipitated from the solution with high K+ and Na+ concentrations as recyclable hematite products by adjusting the concentration ratio of sodium and potassium ions in the solution. The transformation behavior of jarosite into hematite in high concentration potassium ion and sodium ion solution was explained based on collision theory. The results indicated that in instances where the concentration ratio of Na+/K+ is ≥ 4:1, the iron present in the solution can be effectively precipitated as a recyclable hematite product, as opposed to forming the conventional hazardous jarosite residue, even under conditions where the potassium ion concentration reaches levels as high as 4 g/L. On the other hand, thermodynamic and molecular dynamics simulations indicate that at a temperature of 185 °C, the decomposition transformation of Na-jarosite (32.64 kJ and 7.25 eV) is more energetically advantageous compared to that of K-jarosite (61.07 kJ and 15.31 eV). The results were verified by the leaching solution from smelting industry. The iron content in the residues is above 58%, the sulfur content is below 4%, the zinc content is below 1%, and the total iron concentration in the supernatant is about 4 g/L, reaching the production index of the smelting industry. The green, environmentally friendly, and recyclable separation of iron in a solution with high concentrations of potassium and sodium ions is achieved, which is of great significance for the treatment of iron-containing solution and wastewater in the chemical industry and metallurgy fields.

Camellia sinensis leaf-derived magnetite nanoparticles as anti-biofouling nano-fillers in polymer electrolyte membrane for microbial fuel cell application

Membrane biofouling prevents one of the most promising bio-electrochemical systems known as microbial fuel cell (MFC) from operating at its fullest potential. Green tea leaf-mediated biosynthesized and sulphonated iron (II, III) oxide nanoparticles aim to serve as a nanofiller for polymer electrolyte membrane (PEM) to enhance the membrane physicochemical parameters and to improve the membrane anti-biofouling in MFC. Sulphonated polyether ether ketone (SPEEK) grafted styrene sulphonic acid (SSA) incorporated with biosynthesized-sulphonated Fe3O4 (BS-Fe3O4) nanoparticles is used as nanocomposite membranes in the MFC. The results show that 7.5 % BS-Fe3O4 integrated SPEEK/SSA membranes possessed high proton conductivity (8.4x10-2 S cm−1), water uptake (78.2 %), and ion exchange capacity (1.84 meq g−1) than plain SPEEK and commercially available Nafion-117 membrane. The results also reveal that SPEEK/SSA + 7.5 % BS-Fe3O4 membrane showed the highest maximum power density of 210.3 mW m−2 at 190 mA m−2 current density after 4 weeks of MFC operation. The heightened performance of the mentioned nanocomposite membranes is due to their exceptional anti-biofouling property as observed through zone of inhibition (10.25 mm) and biofilm inhibition tests (74.1 %). The prepared membranes also exhibited good mechanical and oxidative stability required for long-term operation. Finally, the phylogenetic analysis discloses the maximum presence of the Pseudomonas (∼54.75 %), Acidovax (∼9.5 %), Janthinobacteriu (∼4.84 %), Flavoacterium (∼2.77 %), and Thermomonas (∼2.66 %). This study provides avenues for interdisciplinary research in green synthesis, functionalization of nanomaterials, polymer synthesis, and MFCs to address current research gaps.

Optimizing Nanofluidic Energy Harvesting in Synthetic Clay-based Membranes by Annealing Treatment.

Nanofluidic energy harvesting from salinity gradients is studied in 2D nanomaterials-based membranes with promising performance as high ion selectivity and fast ion transport. In addition, moving forward to scalable, feasible systems requires environmentally friendly materials to make the application sustainable. Clay-based membranes are attractive for being environmentally friendly, non-hazardous, and easy to manipulate materials. However, achieving underwater stability for clay-based membranes remains challenging. In this work, the synthetic clay Laponite is used to prepare clay-based membranes with high stability and excellent performance for osmotic energy harvesting. The Laponite membranes (Lap-membranes) are stabilized by low-temperature annealing treatment to effectively reduce the interlayer space, achieving a continuous operation under salinity gradients. Furthermore, the Lap-membranes conserve integrity while soaking in water for more than one month. The output power density improves from ≈4.97W m-2 on the pristine membrane to ≈9.89W m-2 in the membrane treated 12 h at 300°C from a 30-fold concentration gradient. Especially, It is found that the presence of interlayer water to be favorable for ion transport. Different mechanisms are proposed in the Lap-membranes involved for efficient ion selectivity and the states found with varying annealing temperatures. This work demonstrates the potential application of Laponite based nanomaterials for nanofluidic energy harvesting.