Search Results (532)

Background: The regulation of inorganic phosphate (Pi) homeostasis is predominantly mediated by the Pi transporters belonging to the SLC34 and SLC20 families of solute carriers. However, not all Pi handling can be explained by these transporters. In this study, we sought to identify novel Pi transporters in accordance with prior findings on inhibition patterns. Methods: We have performed a functional screening of new Pi carriers using the Xenopus laevis oocyte expression system, focusing on the SLC26 family, and corroboration in cell culture. Results: Both SLC26A7 and SLC26A9 have been shown to express sodium-activated Pi uptakes with approximately 200 µmol/L Pi affinity. In both cases, Pi transport is inhibited by increasing pH and by phosphonoformate, arsenate, bicarbonate, sulfate, the chloride channel inhibitor 5-nitro-2-[(3-phenylpropyl)amino]-benzoate, and several transport site and translocation inhibitors of bicarbonate exchangers. In addition, the CFTR inhibitor GlyH-101 and the SLC4 inhibitors DIDS, SITS, and phloretin exhibited partial inhibition of SLC26A9-mediated Pi uptake. The endogenous expressions of both SLC26A7 and SLC26A9 in the renal cell lines LLC-PK1 and MDCK were primarily intracellular, colocalizing with endosomes, lysosomes, and the trans-Golgi network markers. Conversely, plasma membrane expression was found to be minimal. Pi transport in MDCK cells was sodium-independent, but when either SLC26A7 or SLC26A9 was overexpressed, sodium-activated Pi uptake was observed, along with increased expressions of SLC26A7 or SLC26A9 in the plasma membrane. Conclusions: Sodium-activated Pi transport is a novel function of the SLC26A7 and SLC26A9 multifunctional anion transporters. Further research is necessary to ascertain the relevance to Pi homeostasis in vivo. Full article

Today, the development of ion exchange membranes has increased considerably in various applications, such as water treatment, energy conversion and storage, as well as environmental applications. In this study, several ion exchange membranes based on cellulose acetate propionate (CAP) and ionic liquids (ILs) were fabricated using the phase inversion method, aiming to develop more sustainable membrane materials for environmental and energy applications. Three different ILs with a similar cation and different anions (1-(4-sulfobutyl)-3-methylimidazolium trifluoromethanesulfonate [SMIM][TFS], 1-(4-sulfobutyl)-3-methylimidazolium hydrogen sulfate [SMIM][HS], and 1-(4-sulfobutyl)-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [SMIM][TFSI]) were used in three concentrations (i.e., 9, 17, and 23 wt.%). The main objective of this work is to evaluate the influence of the anion structure on the membrane’s physical, morphological, hydrophilic, thermal, mechanical, and electrochemical properties. Water contact angle measurements demonstrated the weaker hydrophilicity of composite membranes containing [SMIM][TFS] (81–106°) and [SMIM][TFSI] (87–94°) in comparison with pure CAP (~79°) and CAP/[SMIM][HS] (79–83°) membranes. The CAP/[SMIM][HS] membrane showed higher elongation at break (~36%) compared with the pure CAP membrane (~24%), confirming the plasticization behavior of [SMIM][HS]. The CAP/[SMIM][TFS] membrane containing 23 wt.% of IL showed promising membrane potential, permselectivity, transport number and ion flux ratio values of 53.2 mV, 74.7%, 0.85, and 5.5, respectively, indicating its potential as a candidate for further evaluation in electrochemical membrane processes such as electrodialysis and fuel cells. Full article

Hydrogen energy, as an important green energy source, is a crucial guarantee for achieving carbon neutrality and peak carbon emission. The anion exchange membrane (AEM) electrolysis cell combines the advantages of alkaline electrolysis cell and proton exchange membrane electrolysis cell and can employ non-precious metal catalysts combined with renewable energy, which is expected to break through the bottleneck of high production cost of green hydrogen. AEM water electrolysis combines the advantages of alkaline and proton exchange membrane water electrolysis for hydrogen production. It has the characteristics of high electrolysis efficiency, fast response rates, and low cost, and its considered one of the most promising renewable green energy hydrogen production technologies at present. AEM is a key component that provides OH^– ion conduction and blocks gas crossover, which directly affects the performance and service life of the AEM electrolysis water system. However, current AEMs face issues of low ion conductivity and poor stability. This review introduces the role of AEM in electrolytic cells, the performance requirements and evaluation parameters that high-performance AEM should meet, and focuses on the transport mechanism and influencing factors of OH^– in AEM. Furthermore, this review provides an overview of the structural composition of AEM, as well as common cationic groups and polymer backbone types. The degradation mechanism of various cationic groups and the characteristics of polymer main chains were elaborated, with a focus on the strategies for designing the stability of cationic functional groups, the methods for modifying and preparing polymer main chains, and the performance of AEMs. Finally, the future challenges and potential research directions of AEM membranes are discussed. It is suggested that high-performance AEMs meeting practical application needs should be developed through strategies such as crosslinking, block copolymerization, side chain grafting, and composite membrane technology, based on the design of alkali-resistant and stable AEM membranes. These insights provide reference and guidance for the further development of AEMs. Full article

The transition toward low-carbon energy systems has intensified interest in sustainable hydrogen production technologies. One of the most promising methods for producing green hydrogen is water electrolysis powered by renewable energy. This work reviews recent advances in electrode materials used in four major electrolysis technologies: alkaline (ALK), proton exchange membrane (PEM), solid oxide electrolysis cells (SOEC), and anion exchange membrane (AEM). A bibliometric analysis of scientific publications from 2021 to 2025 highlights the rapid growth of research and the increasing importance of electrode materials in improving electrolysis performance. Operating environments, material requirements, and catalytic properties are compared across these systems. Recent developments in electrocatalysts—including transition-metal alloys, heterostructured catalysts, defect-engineered materials, and nanostructured systems—are evaluated in terms of catalytic activity, durability, and scalability. Particular attention is given to reducing noble metal usage while maintaining high electrochemical performance. Results indicate that transition-metal-based catalysts and engineered interfaces can achieve activity comparable to noble-metal systems while offering better cost efficiency. However, challenges related to long-term durability, large-scale synthesis, and standardized testing persist. Continued interdisciplinary research in materials design and electrochemical engineering is essential to enable efficient, durable, and cost-effective green hydrogen production. Full article

Microbial fuel cells (MFCs) offer a promising pathway for treating wastewater while simultaneously generating electricity; however, they remain largely pilot-scale technology due to persistent limitations, such as low power density. Microalgae can act as in situ oxygen suppliers in the cathode chamber of dual chamber MFCs, enhancing electricity generation while facilitating nutrient removal. This study compares the performance of cathodic microalgae in MFCs utilizing either a cation exchange membrane (CEM) or an anion exchange membrane (AEM). Raw municipal wastewater collected from the preliminary tank was used as the anodic substrate, while pre-cultivated Chlorella vulgaris (optical density ≈ 0.42) was introduced into the cathode chambers. The performance of both configurations was constantly monitored through various analytical methods. The AEM-based MFC produced significantly higher and more stable voltages (avg. 0.05 volts; peak ≈ 0.11 volts) and achieved a 0.95 mW/m² peak power density, compared to the CEM-based MFC, which produced lower voltages (avg. 0.01 volts; peak ≈ 0.06 volts) and achieved a 0.25 mW/m² peak power density. No significant differences in nutrient removal rates were found among the membranes. Findings demonstrate the superiority of AEM configurations for microalgae-assisted MFCs, establishing a more viable framework for potential large-scale wastewater treatment applications. Full article

To mitigate the gas–liquid mass-transfer bottleneck in anion-exchange membrane water electrolysis (AEMWE), a 3D multiphysics numerical model was developed to systematically investigate the regulatory effects of gradient porosity (GPD) and gradient pore-size distribution (GPSD) on anode reaction kinetics and cell polarization. Single-factor analysis reveals that increasing the GPD/GPSD from the membrane side toward the flow channel side effectively reduces activation overpotential due to the high specific surface area of small pores near the membrane, while simultaneously lowering mass-transfer resistance through high porosity and large pores near the flow channel. Conversely, a decreasing gradient leads to localized gas stagnation and uneven mass transfer, deteriorating cell performance. Furthermore, an innovative synergistic design is proposed featuring a simultaneous linear increase in porosity (0.6 to 0.9) and pore diameter (0.11 to 0.17 mm). This configuration achieves a cell voltage of only 1.812 V at 1100 mA/cm² (1 mol/L KOH, 80 °C), approximately 40 mV lower than that of conventional uniform structures, thereby significantly reducing energy consumption at high current densities. This study provides a mechanistic framework for the precise architectural design of high-performance AEMWE electrodes, highlighting the importance of spatial heterogeneity in optimizing two-phase transport. Full article

With the rising interest in hydrogen technologies as a pathway toward lower-carbon energy systems, there is a growing need for proton exchange membranes that can operate reliably in the 120–200 °C window. This second part of the review examines mixed phosphate–silicate networks, composites, and hybrid membranes designed to move beyond the limitations of the single-anion glasses discussed in Part I. Rather than listing compositions only, the present analysis is organized around a comparative framework that links network chemistry, hydration management, pore-space morphology, interfacial proton transport, and durability under thermal/humidity cycling. Mixed-anion lattices, sol–gel-derived porous glasses, polymer-assisted interpenetrating networks, ionic-liquid-modified systems, fully inorganic composites, and mechanochemically prepared hybrids are evaluated with respect to conductivity, humidity tolerance, structural stability, and device relevance. Particular attention is paid to strategies that attempt to decouple proton conductivity from simple water uptake by combining acidic-site engineering with mesostructural control. The literature shows that recent progress is real but uneven. Conductivity gains are often achieved through better retention of hydrated proton pathways or acid-rich interphases, yet these benefits remain constrained by pore collapse, acid migration, gas crossover, interfacial losses, or insufficient long-term validation in membrane–electrode assemblies. The review, therefore, closes with a cross-class benchmarking matrix and a synthesis-oriented guide intended to support more critical comparison of future intermediate-temperature membrane designs. Full article

The accelerated deployment of hydrogen technologies is widely discussed as a pathway to mitigate climate change and reduce environmental pollution associated with fossil fuel use. In this context, intermediate-temperature proton-exchange membranes that operate in the 120–200 °C window, similar to the one characterizing liquid-acid PAFC systems (much larger in their power range), are sought as a bridge between low-temperature PFSA-based PEMFCs and low-temperature PCFs, thus combining reduced sensitivity to external humidification with solid-electrolyte handling. This Part I review surveys phosphate- and silicate-based glassy proton conductors as single-anion baseline matrices and organizes the literature around a mechanistic screening framework that links processing fingerprints—particularly sol–gel hydrolysis/condensation conditions, aging, drying, and thermal treatment—to pore architecture, hydration state, and the dominant proton-transport regime. Across both families, conductivity is governed by coupled variables: network chemistry (acidic site density and connectivity), water activity (RH), and microstructure-controlled percolation and retention. Reported σ values can arise from fundamentally different regimes, ranging from hopping-dominated transport supported by dense hydrogen-bond networks and proton-bearing groups to carrier-assisted, water-mediated transport in connected porosity, with distinct humidity dependence and stability implications. Accordingly, the review treats σ(T,RH) and activation energy together with hydration/porosity indicators as primary screening metrics, and it records missing durability and device-level information—chemical stability (hydrolysis and leaching/acid migration), mechanical robustness and cycling response, and current/power density where available—as explicit knowledge gaps. While substantial progress has been achieved within single-anion phosphate and silicate glasses, particularly through engineered acidity and microstructural control, most systems remain limited by hydration drift under gradients, thermal/humidity cycling stability, and electrode/electrolyte interfacial constraints when evaluated against intermediate-temperature membrane requirements. These conclusions establish a quantitative baseline and comparison rules for Part II, which will assess mixed-network, composite, and hybrid strategies designed to decouple conductivity from water-retention and durability trade-offs. Full article

Alkaline water electrolysis (AWE) is a pivotal technology for sustainable hydrogen production. However, hydrogen permeation through its membranes remains a critical concern, as excessive gas crossover can lead to the formation of explosive mixtures and pose severe safety hazards. While conventional measurement techniques, such as pressure drop and electrochemical methods, are suitable for porous membranes, they exhibit inherent limitations when applied to dense membranes such as anion exchange membranes. This study proposes a cross-flow measurement methodology applicable to all types of AWE membranes. Unlike traditional dead-end configurations, the cross-flow approach effectively mitigates impurity accumulation and maintains a continuous electrolyte flow parallel to the membrane surface. This configuration ensures uniform electrolyte distribution, minimizes local concentration and pressure fluctuations, and enhances measurement reliability and reproducibility relative to the conventional dead-end flow. Furthermore, the methodology ensures accurate and reproducible measurements, demonstrating enhanced detection capability for dense membranes with intrinsically low permeability by mitigating fouling and concentration polarization effects. These findings provide a robust framework for the development of high-performance membranes designed to suppress dissolved hydrogen permeability. Full article

The sluggish kinetics of the hydrogen oxidation reaction (HOR) in alkaline media remain a primary bottleneck for anion exchange membrane fuel cells (AEMFCs), necessitating catalysts that synergistically optimize the adsorption of hydrogen (*H) and hydroxide (*OH) intermediates. Herein, we construct a well-defined heterointerface between Pd clusters and CeO₂ on nitrogen-doped carbon (Pd-CeO₂/NC) to electronically engineer the active sites. Spectroscopic studies and theoretical calculations collectively reveal that CeO₂ acts as an electron acceptor, drawing electrons from Pd via interfacial Pd-O-Ce bridges. This charge transfer induces a downshift of the Pd d-band center, which optimally tunes the adsorption strength of both *H and *OH at the interface, thereby breaking the scaling relationship that limits HOR activity. The resulting Pd-CeO₂/NC catalyst achieves an exceptional exchange current density of 3.66 mA cm⁻², surpassing that of commercial Pt/C by a factor of two and ranking among the best reported noble metal catalysts. Furthermore, it exhibits outstanding long-term stability and remarkable CO tolerance, retaining high activity in an atmosphere containing 1000 ppm CO. This work underscores the profound efficacy of metal–oxide heterointerface engineering in regulating electronic structures for multi-intermediate optimization, offering a viable design principle for advanced alkaline HOR electrocatalysts. Full article

Sulfide-alkaline wastewater (SAW) from petrochemical plants, particularly from pyrolysis and hydrotreating units, presents a significant environmental challenge due to its high toxicity, extreme alkalinity (pH > 12), and high concentrations of sulfides and organic pollutants. Traditional treatment methods like acid neutralization or air oxidation are often inefficient, generate secondary waste, or fail to recover valuable components. This study investigates the effectiveness of a novel electrochemical system for the simultaneous treatment of SAW and recovery of valuable products. A lab-scale four-chamber electrodialyzer, equipped with cation-exchange membranes and nickel bipolar electrodes, was designed and tested using real industrial wastewater. The wastewater was characterized by a pH of 13.06, chemical oxygen demand of 12,600 mg/L, and a sulfide content of approximately 5000 mg/L. The process leverages anodic oxidation to convert sulfide ions into elemental sulfur, while sodium cations migrate through cation-exchange membranes to the cathodic compartments. There, water reduction generates high-purity hydrogen (≥99.9%) and a concentrated, purified sodium hydroxide solution. The results demonstrate the ineffectiveness of electrodialysis with anion-exchange membranes due to rapid membrane degradation. In contrast, the proposed electrodialyzer with bipolar electrodes achieved excellent performance: a caustic soda solution with a concentration of 2.3–2.5% was recovered with a current efficiency of 83–85%, containing only trace amounts of sulfides (0.0052%) and organic impurities (0.053%). The process completely removed the original sulfide alkalinity. The study confirms the chemical and mechanical stability of the cation-exchange membranes under harsh SAW conditions. The proposed technology offers a path towards a closed-loop system in refineries by enabling the reuse of recovered caustic, utilization of hydrogen, and potential recovery of sulfur, aligning with the principles of green chemistry and circular economy. Full article

Background: Rabies is a highly fatal zoonotic disease that causes approximately 59,000 human deaths worldwide each year. Current inactivated rabies vaccines require multiple doses and are associated with high costs. The full-length rabies virus glycoprotein (RVG), a membrane protein, exhibits substantial instability in its trimeric structure during recombinant expression. This instability makes it difficult to obtain high-purity, correctly folded antigens. Objectives: This study focuses on the preparation of a full-length recombinant RVG subunit vaccine candidate expressed in a glycoengineered Pichia pastoris system with mammalian-like glycosylation. Methods: The full-length RVG gene (including the transmembrane domain and cytoplasmic tail) from the Challenge Virus Standard-11 (CVS-11) strain was codon-optimized and inserted into the pPICZαA vector to construct the recombinant expression plasmid pPICZαA-RVG. The plasmid was transformed into glycoengineered Pichia pastoris X33-7 (low-mannose type) by electroporation for inducible expression. The target protein was purified by nickel affinity chromatography, anion-exchange chromatography, and Superdex-200 size-exclusion chromatography. The structural characteristics of the purified protein were analyzed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The purified antigen was formulated with the adjuvants AS03 or MF59. BALB/c mice (n = 5 per group) were immunized intramuscularly following a four-dose schedule (days 0, 7, 14, and 28). Antigen-specific IgG antibody titers were measured by ELISA, and neutralizing antibody titers were determined using the rapid fluorescent focus inhibition test (RFFIT). Results: Glycoengineered Pichia pastoris yeast strains expressing wild-type RVG (RVG-WT) or a mutant variant (RVG-M6: R84S, R199S, H270P, R279S, K300S, and R463S) were successfully constructed. The purified RVG antigen formed nanoparticles with an average particle size of approximately 75 nm. Immunized mice generated robust RVG-specific IgG responses, with titers reaching approximately 6.31 × 10⁵ for RVG-WT after the fourth immunization, compared to 3.16 × 10³ for RVG-M6 and 5.62 × 10³ for the RVG-WT-PEG control. Two weeks after the fourth immunization, RVG-WT formulated with AS03 or MF59 induced significant neutralizing antibody responses compared with the control group (p < 0.0001 and p < 0.01, respectively). The neutralizing antibody titers reached 1:79.43 in the AS03 group and 1:33.11 in the MF59 group, whereas the WT-PEG + AS03 control group showed a low titer of 1:3.72. In contrast, RVG-M6 formulated with MF59 failed to induce detectable neutralizing antibodies (1:3.02). Furthermore, RVG-WT + AS03 induced significantly higher neutralizing antibody responses than the WT-PEG + AS03 control group (p < 0.0001), and a significant difference was also observed between the RVG-WT + MF59 and RVG-M6 + MF59 groups (p < 0.01). Conclusions: The glycoengineered Pichia pastoris expression system successfully produced uniform full-length rabies virus glycoprotein nanoparticles with high purity. When formulated with the AS03 adjuvant, RVG-WT induced high-titer neutralizing antibodies in mice, suggesting a promising strategy for the development of recombinant subunit vaccines against rabies. However, this study is limited by the absence of challenge studies and validation in target animal species, which will be further investigated in future work. Full article

Mitigating pollution in cities where transportation powered by fossil fuels has a significant impact on human health is a public health priority. Although electric vehicles are one solution to this problem, their high acquisition and maintenance costs have limited their rapid adoption; therefore, other solutions may be useful in supporting reduction efforts. Therefore, this paper proposes a power control system for an Anion Exchange Membrane Fuel Cell (AEMFC) generator powered by hydrogen with the capacity to supply a direct current (DC) motor of 0.75 kW. A mathematical model of the AEMFC was proposed, and the parameters were adjusted to obtain polarization and power curves defining safe operating ranges (12.45–17.9 V). A boost converter was designed to increase the voltage of the cell output to 48 V to meet the requirements of the DC motor. The performance of the power converter was studied by analyzing its small-signal ripple, operating modes, and efficiency. The models and simulations were implemented using MATLAB and PSIM. A cascaded control system with proportional–integral (PI) and proportional–integral–derivative (PID) controllers was implemented to maintain voltage stability in the presence of input and load variation. The results show that the AEMFC is reliable and that the boost converter presents an efficiency higher than 98% in continuous mode. The robustness of the model was validated through simulations and using a prototype. Full article

A flexible polyionic liquid (PIL) nanofiber membrane-supported phosphomolybdic acid catalyst (PM-PIL) was fabricated via stepwise chemical transformation of polyacrylonitrile (PAN) nanofiber membranes. The nitrile groups of PAN were converted into pyridine units, followed by quaternization and anion exchange with phosphomolybdic acid (PMo), resulting in a polyionic liquid membrane with uniformly immobilized PMo species. Benefiting from its nanofibrous architecture and ionic liquid characteristics, the PM-PIL membrane simultaneously acts as a heterogeneous catalyst and a Pickering emulsion stabilizer, enabling efficient interfacial catalytic oxidation desulfurization. The PM-PIL membrane exhibited excellent catalytic performance toward dibenzothiophene (DBT) oxidation in an H₂O₂-based model oil system. Under optimized conditions (60 °C, O/S = 150:1), more than 90% DBT removal was achieved within 90 min, and complete desulfurization was obtained within 2 h. Compared with phosphomolybdic acid and poly(pyridine), the PM-PIL membrane showed markedly enhanced activity and stability, maintaining over 90% efficiency after six cycles. Product analysis confirmed selective oxidation of DBT to dibenzothiophene sulfone. This work provides a robust and recyclable membrane-based catalytic platform for efficient oxidative desulfurization. Full article

The rapid increase in end-of-life lithium-ion batteries demands sustainable recycling routes for lithium recovery. This work presents a novel integrated hydrometallurgical–electrodialysis process designed specifically for recovering lithium from off-specification NMC cathode materials while enabling full reagent recyclability. Selective leaching with oxalic acid was optimised by setting the water-to-oxalic acid dihydrate ratio (H₂O/OA·2H₂O) to 7.3:1 w/w, achieving 81% lithium extraction at room temperature within 2 h while limiting the co-dissolution of Ni, Co and Mn to 0.2%, 1.6% and 1.7% by weight, respectively. The resulting leachate was processed in a four-chamber electrodialysis cell equipped with two Nafion 117 cation-exchange membranes and one Neosepta AMX-fmg anion-exchange membrane operating at −1.6 V versus Ag/AgCl, enabling 96% lithium recovery and 98% oxalic acid recovery. The regenerated oxalic acid stream (41.8 g L⁻¹) was fully restored to its initial concentration and reused in successive cycles without performance loss. Subsequent precipitation of lithium with Na₂CO₃ yielded 99.3%-pure Li₂CO₃. This combined leaching–electrodialysis–precipitation presents a high selectivity, low-waste, circular recovery system, offering a scientifically original approach that integrates reagent regeneration with high-purity lithium production. Full article