A novel thermal strategy precisely tailors Mn-based cationic defects in MOF-derived inverse spinel Al8Fe16O32 embedded within partially graphitized carbon. This defect engineering greatly enhances electrical conductivity, ion transport, redox activity, and structural stability. As supported through XRD, HR-TEM/STEM mapping, XPS, and XAS (XANES/EXAFS), elevated temperatures and extended soak times promote cation mobility, antisite exchange, vacancy equilibration, and phase transitions. Further, due to enriched Fe/Mn defect sites and enhanced redox/pseudo capacitance behaviour, the defective MnOx-(Al-8)[Fe16-xMnx]O-32@AHGC electrode demonstrates a much higher specific capacitance (96 F g(-1)) than pristine Al8Fe16O32@AHGC (12.7 F g(-1)). The assembled HSC device AC // MnOx-(Al-8)[Fe16-xMnx]O-32@AHGC delivers 78 % rate capability, an energy density of 25.4 Wh kg(-1) (similar to 40 % higher than that of pristine), and 89 % capacitance retention after 10,000 GCD cycles at 7.5 A g(-1). This work highlights the potential of defect engineering in inverse spinel oxides combined with MOF-derived hierarchical partially graphitized carbon for advancing next-generation energy storage systems.

Wet nonaqueous electrolytes can markedly improve Zn anode reversibility in zinc-ion batteries (ZIBs), yet cathode instability remains a critical barrier because MnO2 commonly undergoes dissolution-redeposition, interfacial reconstruction, and irreversible byproduct formation. Here, we show that this limitation can be mitigated through cathode intergrowth engineering rather than electrolyte optimization alone. An intergrowthtype MnO2 cathode, prepared through a Mn-Al precursor route followed by persulfate oxidation, exhibits substantially more stable operation in a wet nonaqueous Zn electrolyte than conventional delta-MnO2. It delivers discharge capacities of 147-96 mAh g- 1 over 0.05-0.5 A g- 1, retains about 97% of its initial capacity after 500 cycles, and maintains about 84% capacity retention after 2500 cycles. Bulk operando XANES, in situ grazingincidence XANES, fluorescence tracking, and operando XRD collectively show that the improved durability is associated with highly reversible Mn redox, enhanced Mn retention at the cathode interface, reversible framework expansion without severe structural collapse, and suppression of irreversible ZnO formation. These results support intergrowth engineering as a promising strategy for stabilizing MnO2 cathodes in wet nonaqueous ZIBs and provide a practical design principle for durable cathode operation through coupled bulk structural adaptability and controlled interfacial evolution.

Due to their high theoretical energy capacity, zinc-polyiodide flow batteries (ZIFBs) are promising candidates for large-scale energy storage devices. Their practical performance, however, is strongly influenced by the separator, which must exhibit high ionic conductivity to enable efficient ion transport during battery operation. In this study, a functionalized zirconium-based metal-organic framework (sUiO-66) is synthesized via a solvothermal method. The synthesized sUiO-66 is subsequently incorporated into a sulfonated poly (ether ether ketone) (sPEEK) matrix to fabricate a composite separator through a solvent-casting method. With sUiO-66 incorporation, the composite separator exhibits enhanced ionic conductivity and mechanical strength, both of which are advantageous for ZIFB performance. Results demonstrate that SP/sUiO-66-15 exhibits enhanced ion-transport capability, supported by its high proton conductivity and improved ionic conductivity in the practical ZIFB electrolyte. Hence, the ZIFB assembled with SP/sUiO-66-15 delivers relatively stable cycling performance over 200 cycles under the tested conditions, with a coulombic efficiency (CE) of 95.8% and voltage efficiency (VE) of 89.8% at a current density of 10 mA·cm−2. These findings show that the sPEEK/sUiO-66 composite separator improves ZIFB efficiency by enhancing ion transport, whilst triiodide crossover still needs to be controlled at higher sUiO-66 loading.

Oxide-oxide heterostructures offer a route to supercapacitor electrodes in which redox capacity and interfacial polarization are supplied by chemically distinct phases. Here the dielectric oxide Ta2O5 is coupled with multiferroic BiFeO3, and operando X-ray absorption spectroscopy at two absorption edges of the same working electrode is used to determine which cation stores charge. Structural and microscopic analysis confirms a two-phase heterostructure with direct Ta2O5-BiFeO3 contact, and pellet impedance resolves Maxwell-Wagner interfacial polarization in all three materials, the composite the least lossy. Operando Fe K-edge XANES resolves no change in the bulk-averaged Fe oxidation state once the spectra share a common normalization, and bounds any reversible component at 0.011 units of mean oxidation state, below 1.4% of the charge the electrode stores in one cycle. Under identical conditions the Ta L3 white line lies at the Ta5 + end of the Ta0-to-Ta5+ reference interval in every state and the Ta-O first shell is unchanged, so no Ta-centered change in oxidation state is assigned. The mechanism is therefore bounded by measurement, not asserted. Surface-sensitive XPS nevertheless resolves a mixed Fe²⁺/Fe³ ⁺ state, consistent with a near-surface Fe redox contribution that the volume-averaging operando XAS can only bound. The composite delivers 156 F g−1 at 1 mV s−1, and a symmetric device 34 Wh kg−1 at 558 W kg−1 with 82% capacitance retention after 10 000 cycles.

Electrolyte composition strongly influences the cycling performance of tunnel-type Na0.44MnO2 (NMO), yet additive selection for this cathode remains largely empirical. Here, we evaluate a dual-additive electrolyte containing fluoroethylene carbonate (FEC) and nominally added trace sodium fluoride (NaF) in a carbonate-ester baseline to determine how the formulation affects Na+ solvation and electrode interfacial behavior. Raman spectroscopy and molecular dynamics simulations identify FEC as the principal additive that decreases Na+–EC coordination and promotes relatively greater anion participation in the first solvation shell; under the conditions examined, trace NaF contributes only modestly. The dual-additive formulation exhibits limited impedance growth during prolonged cycling, relatively balanced apparent Na+ transport during insertion and extraction, and largely reversible structural evolution of the tunnel framework, as observed by in situ synchrotron X-ray diffraction. Two-electrode Na||NMO cells using this electrolyte retain 95.6% of their cycle-2 capacity after 150 cycles at 1C, comparable to the FEC-only formulation (95.9%) and higher than the NaF-only (74.3%) and baseline (66.6%) formulations, while providing the highest discharge capacity at each rate tested. NMO||hard‑carbon full cells with the same electrolyte retain 88.2% of their cycle-2 discharge capacity after 130 cycles at 1C and achieve an average Coulombic efficiency of 99.84% over cycles 2–187.

Due to their potential electrochemical features, including high theoretical capacitance, environmental friendliness, and cost-effectiveness, manganese sulfide (MnS) based supercapacitors (SCs) have sparked interest. However, to optimize their performance and commercial viability, such as limited cycling stability, low electrical conductivity, aggregation of nanostructures, dissolution in electrolytes, scaling up, and high cost, several challenges need to be addressed. This study explores hybrid architecture and innovative design strategies to enhance energy density and performance of SCs while maintaining their inherent advantages. Results demonstrate that the g-C3N4/sulfur@MnS electrode reached a high specific capacitance of 493 F/g at 0.5 A/g. The full device, combining g-C3N4/sulfur@MnS with activated carbon, achieves an energy density of 18.7 Wh/kg, a power density of 327 W/kg, and maintains 81 % capacitance retention after 5000 cycles. These exceptional electrochemical properties arise from the enhanced surface area, optimized pore volume, and robust redox activity of the hybrid system. Our findings position the g-C3N4/sulfur@MnS system as a leading candidate for nextgeneration SCs, combining high performance with long-term stability.

Emerging Per and polyfluoroalkyl substances (PFAS) have become a growing concern due to their widespread presence, persistence, and potential health hazards. They are broadly classified into polymeric and non-polymeric PFAS. While regulatory initiatives have limited the use of long-chain PFAS such as perfluorooctanoic acid (C8) (PFOA) and perfluorooctane sulfonic acid (C8) (PFOS), industries like food packaging, textiles, firefighting foam, semiconductors, and electronics are now shifting toward short-chain PFAS and novel fluorine-free alternatives. However, these short-chain PFAS have high mobility, environmental persistence, and potential bioaccumulation, raising concern about their long-term effects on human health, wildlife, and ecosystems. These chemicals have been found in several environmental matrices and also in various food products. Exposure to these PFAS, mainly through polluted drinking water, food items, and consumer products, leads to potential health hazards, including liver, kidney, and nerve damage, endocrine disruptions, immune system dysfunction, developmental issues, and increased risk of cancer. Several destructive and nondestructive treatment techniques, including adsorption, membrane technology, advanced oxidation process, photocatalytic degradation, and microbial degradation, have been explored to remove PFAS from various matrices. In addition, scientists and policymakers globally are promoting stricter regulations and the development of sustainable alternatives. This review provides a comprehensive overview of PFAS occurrence, classification, regulatory limits, health impacts, current removal strategies, and highlights various fluorine-free alternatives.

Poor stability of zinc (Zn) anode hinders the use of aqueous zinc-ion batteries (AZIBs) for large-scale energy storage. Here, we report an effective artificial solid electrolyte interphase (ASEI) using N-doped carbon dots (CDs) and SnO2 to stabilize Zn anodes. By optimizing the CDs/SnO2 ratio, we can synthesize porous composites to construct "bayberry" and flower-like morphologies. The N-doped CDs/SnO2 anode creates surface dipoles and changes in charge distribution, allowing Zn ions to move to nitrogen functionalized sites with reduced adsorption barriers. Furthermore, hydroxyl oxygen boosts the surface's hydrophilicity, resulting in stronger adhesion to the Zn anode and better ion accessibility. This generates dense nucleation sites for uniform Zn deposition. The CDs/SnO2@Zn electrode achieves a low nucleation potential of 47mV and maintains 99.6% coulombic efficiency (CE) over 1000 cycles at 2mAcm-2. In the symmetrical cells, the modified Zn anode exhibits stable cycling for 1,200h at 1 mAh cm-2. A full cell with CDs/SnO2@Zn anode and MnO2 cathode retains 96.6% capacity after 800h. This study introduces a promising strategy for stabilizing Zn anodes and offers valuable insights for designing dendrite-free electrodes in next-generation AZIBs.

Despite their high conductivity and surface area, carbon substrates often suffer from poor dispersion and limited functional groups, hindering their effective integration with active materials in supercapacitors (SCs). Here, we present a fused bimetallic heterojunction (Ni9S6-Co9S8@FGC) anchored on glucose-derived porous graphitic carbon balls, and synthesized via a one-step hydrothermal approach. This design combines the electrochemical benefits of nickel and cobalt sulfides with the structural stability and high porosity of graphitic carbon. The Ni9S6-Co9S8@FGC/NF electrode achieves a remarkable specific capacitance of 885 F g-1 at 0.5 A g-1, surpassing the performance of Co9S8@FGC/NF (556 F g-1) and Ni9S6@FGC/NF (270 F g-1). The asymmetric supercapacitor (ASC) device achieves impressive energy and power density, successfully powering a red LED light for 30 min. These findings highlight the potential of fused bimetallic heterojunctions in addressing key challenges in energy storage, offering a scalable and sustainable pathway for advanced ASCs.

The development of cost-effective, durable, and high-performance electrocatalysts for oxygen reduction reaction (ORR) is crucial for advancing renewable energy technologies. Here, we report a facile solvent-free synthesis approach, which employs dicyandiamide (DCDA) as both the carbon and nitrogen source, resulting in highly active FeCo alloy nanoparticle-embedded nitrogen-doped carbon nanotubes (FeCo-CNTs) as ORR electrocatalysts. Following acid treatment, the FeCo-CNT-W catalyst exhibited a significantly enhanced surface area of 207.06 m2 g- 1 (compared to 23.25 m2 g- 1 pre-treatment). During treatment, unfavorable species were removed, creating an optimized catalytic structure. The catalyst demonstrated great ORR performance through a fourelectron transfer pathway with minimal hydrogen peroxide formation, surpassing the commercial Pt/C catalysts in both activity and durability. When implemented as a cathode material in a zinc-air battery (ZAB), the FeCo-CNT-W maintained stable performance for 495 h under charge-discharge cycling at 5 mA cm- 2 (compared to 85 h for Pt/C + RuO2) while achieving a superior power density of 70.2 mW cm- 2 at 79.5 mA cm- 2. This work presents a sustainable and scalable approach for developing high-performance non-precious metal electrocatalysts for next-generation energy conversion systems.

For next-generation energy storage systems (ESSs), carbon dots (CDs) have emerged as revolutionary nanomaterials. CDs offer exceptional structural versatility and unique physicochemical properties. This review critically examines the transformative role of CDs in zinc-ion batteries (ZIBs). Recent advances have demonstrated remarkable improvements in battery performance, including enhanced cycling stability (>90 % capacity retention over 1000 cycles), superior rate capability (5 A g-1), and effective dendrite suppression. Herein, we systematically analyze the fundamental aspects of CDs, from size-controlled synthesis methods (2-10 nm) to their distinctive properties, including tunable surface chemistry, quantum confinement effects, and high electrical conductivity (>100 S cm-1). CDs can enhance ZIB performance via multiple mechanisms: namely, dendrite suppressors in anodes, conductivity enhancers in cathodes, electrolyte modifiers for stable ion transport, and functionalized separators for uniform zinc (Zn) deposition. Our critical analysis reveals that CD-modified ZIBs achieve significantly improved performance metrics, including higher specific capacities (>400 mAh g-1), reduced voltage polarization (<100 mV), and enhanced rate performance (>80 % capacity retention at 10C). We also address current challenges in CDs synthesis and integration, including scalability, cost-effectiveness, and long-term stability. Emerging research directions, such as smart responsive CDs and hybrid architectures are further highlighted. This work provides strategic insights for researchers and engineers working towards commercial-scale, high-performance ZIBs, offering a roadmap for sustainable energy storage solutions.

Polyaromatic hydrocarbons (PAHs) pose a global threat in both developed and developing countries due to their adverse effects on various ecosystems. The low molecular weight (LMW) PAHs, widely used in everyday life, are potential contaminants. Being highly volatile, they are often uptaken by plants and enter the food chain, necessitating an effective biodegradation system. Over the last decade, research has advanced significantly in the bacterial biodegradation of PAHs composed of more than three rings. This review focuses on the levels of PAH in soils worldwide and highlights the diverse bacterial communities found in these soils capable of degrading LMW-PAHs. It also elucidates the mechanisms of LMW-PAH degradation by bacteria. Various studies indicate that while individual bacteria contribute to PAH degradation, bacterial consortia promise better degradation efficiency. This review underscores the need for further research in bioremediation using bacterial networks and the development of methods targeting a wide range of LMW-PAHs. In conclusion, optimizing bacterial consortia and enhancing environmental conditions could significantly improve the biodegradation of LMW-PAHs, reducing their ecological and health impacts.

Recent advancements in zinc-air batteries (ZABs) emphasize the need for efficient and sustainable oxygen electrocatalysts. Central to these efforts are metal-organic frameworks (MOFs), renowned for their bifunctional oxygen electrocatalytic capabilities. However, MOFs and their derivatives often exhibit subpar electrical conductivity and stability. Addressing this, we introduce an innovative approach involving MOFs-derived NiFe2O4/TiO2 nanocrystals sandwiched between 2D MXene nanosheets. This hybrid structure, NiFe2O4/TiO2@NC/Ti3C2, successfully enhances conductivity and active site accessibility, thereby enhancing oxygen reduction (ORR) and evolution (OER) reactions. The NiFe2O4/TiO2@Ti3C2-2 hybrid demonstrates excellent bifunctional activity, characterized by a notable ORR's half-wave potential of 0.846 V and an OER's onset potential of 1.5 V with a potential gap (Delta E) of 0.75 V. When employed in a ZAB, the battery achieves a peak power density of 164 mW cm(-2) and maintains cycling stability for over 500 h at 10 mA cm(-2). Beyond serving as conductive scaffolds, Ti3C2 MXene nanosheets have a vital role in preserving surface areas of the NiFe2O4/TiO2@NC materials. This study not only highlights a successful strategy for improving oxygen reactions in ZABs but also opens up new opportunities for the development of advanced MOF@MXene catalysts in energy conversion applications.

Electrochemical energy storage devices with consistent performance, high power output, and energy density are urgently required to meet global energy demand. Zinc-air batteries are quickly gaining popularity as potential energy sources for green energy storage technologies. The air electrodes, combined with some oxygen electrocatalysts, have a significant impact on the cost and performance of Zn-air batteries. However, designing and fabricating efficient electrocatalysts remains a challenge. Because of their unique structural flexibility and uniformly dispersed active sites, metal-organic frameworks (MOFs) have emerged as appealing precursors for the synthesis of a wide range of advanced functional materials. Our research suggests using flexible multi-carboxylic acids and bipyridine ligands to create nanorods like NiFe@MOFs with multiple coordination modes and fascinating architectures. MOF precursors were post-annealed in argon at 750 °C, yielding a cation deficient Ni0.6Fe2.4O4@NC electrocatalyst. This 3D electrocatalyst effectively reduces oxygen (E1/2 = 0.85 V) and evolves oxygen (η10 = 207 mV@10 mA cm-2). Furthermore, a rechargeable zinc-air battery with Ni0.6Fe2.4O4@NC as the cathode demonstrated a high open circuit voltage (OCV) of 1.5 V, a peak power density of 194.6 mW cm-2, and exceptional long-term cycling stability over 300 h (1800 cycles, 10 mA cm-2). The flexible solid-state zinc-air battery demonstrated power density of 68.5 mW cm-2 and long-term durability over 35 h at 5 mA cm-2. The proposed strategy allows for the rational design of cation defect-rich spinel structures attached to ultra-thin, N-doped graphitic carbon sheets in order to enhance active site availability and mass electron transport. Figure 1

Nonaqueous zinc-ion batteries (NZIBs) featuring manganese dioxide (MnO2) cathodes position themselves as viable options for large-scale energy storage systems. Herein, we demonstrate the use of ammonium cation as a preintercalant to improve the performance of the delta-MnO2 cathode in wet dimethyl sulfoxide based electrolytes. Employing in situ X-ray absorption spectroscopy, Raman spectroscopy, and synchrotron X-ray diffraction, we reveal that the integration of ammonium cations promotes the formation of NH-O-Mn networks. These networks are crucial for manipulating the distortion of the MnO6 octahedral units during discharging, thereby mitigating charge disproportionation, which is a primary limitation to MnO2's charge-storage efficiency. The modified MnO2, through this idea, displays a notable improvement in capacity (similar to 247 mAh/g) and can pass charge-discharge cycles up to 500 cycles with a capacity retention of 85%. These findings underscore the potential of modified MnO2 in advancing MnO2-based hosts for Zn-MnO2 batteries, marking significant progress toward next-generation energy storage solutions.

Perovskite oxides exhibit bifunctional activity for both oxygen reduction (ORR) and oxygen evolution reactions (OER), making them prime candidates for energy conversion in applications like fuel cells and metal-air batteries. Their intrinsic catalytic prowess, combined with low-cost, abundance, and diversity, positions them as compelling alternatives to noble metal and metal oxides catalysts. This review encapsulates the nuances of perovskite oxide structures and synthesis techniques, providing insight into pivotal active sites that underscore their bifunctional behavior. The focus centers on the breakthroughs surrounding lanthanum (La) and strontium (Sr)-based perovskite oxides, specifically their roles in zinc-air batteries (ZABs). An introduction to the mechanisms of ORR and OER is provided. Moreover, the light is shed on strategies and determinants central to optimizing the bifunctional performance of La and Sr-based perovskite oxides. This article provides a comprehensive analysis of lanthanum (La) and strontium (Sr) based perovskite oxides in zinc-air batteries, focusing on their role in oxygen reduction and evolution reactions. It discusses these oxides as affordable catalysts, covering synthesis methods, structural characteristics, and their bifunctional activities essential for zinc-air battery efficiency.image

The quest for sustainable and high-performing battery technologies has directed attention towards Zinc (Zn)-manganese dioxide (MnO 2 ) based rechargeable batteries. These batteries emerge as a viable alternative to lithium-ion systems, particularly due to their advantageous raw material supply, cost, and performance parameters. Despite their potential, Zn-MnO 2 batteries face operational challenges, including gas evolution, Zn self-corrosion, and dissolution of the host material when utilized in mild acid aqueous electrolytes. Addressing these issues, our research explores the efficacy of wet nonaqueous electrolytes as a solution. Previously, we demonstrated a substantial enhancement in battery performance (~200 mAh/g of MnO 2 ) by incorporating a specific proportion of water into the nonaqueous electrolyte. Building on this foundation, our current study investigates the role of hydrogen-bonded pillars, particularly proton and ammonium cations, in augmenting the interfacial properties of MnO 2 . This modification aims to bolster surface kinetics, thereby elevating battery performance closer to that of aqueous systems. Employing a suite of material characterization techniques, including in-situ X-ray absorption spectroscopy (XAS), Raman spectroscopy, and synchrotron X-ray diffraction (XRD), we observed a notable performance improvement (~270 mAh/g), while maintaining stability. These findings hold significant promise for advancing the practical application of MnO 2 -based hosts in Zn-MnO 2 batteries, marking a stride towards next-generation energy storage solutions.

This study presents a facile preparation and durable amorphous Fe and Al-based MOF nanoplate (AlFe-BTC MOFs) catalyst with notable stability in Fenton reactions. Rigorous characterization using XRD, HR-TEM, and BET confirms the amorphous nature of the synthesized AlFe-BTC MOFs, revealing mesopores (3.4 nm diameter), a substantial surface area (232 m2/g), and a pore volume of 0.69 cc/g. XPS analysis delineates distinct Al2p and Fe2p binding energy values, signifying specific chemical bonding. FE-SEM elemental mapping elucidates the distinctive distribution of Fe and Al within the framework of AlFe-BTC MOFs. In catalytic activity testing, the amorphous AlFe-BTC MOFs exhibited outstanding performance, achieving complete degradation of Methylene blue (MB) dye and 78

The growing environmental challenge posed by the persistence of tetracycline (TC) antibiotics in natural waters is of increasing concern. To address this, there is an imperative need for advanced methods to mitigate TC residues. Herein, we demonstrate the preparation of nitrogen-doped graphitic carbon nitride integrated with magnetic Fe3O4 (N-g-CN/Fe3O4) composites, showcasing narrow band gaps optimized for TC degradation. These advanced materials, conceived through a thermal poly-condensation approach, utilize citric acid and melamine as precursors for nitrogen and g-CN, respectively. These composites exhibit a face-centered cubic architecture, with particle dimensions between 8 to 12 nm and encompassing both meso and microporous structure. The results of the Brunauer–Emmett–Teller analysis indicated specific surface areas of 6.73 m²/g for g-CN, 69.80 m²/g for N-g-CN, 62.55 m²/g for Fe3O4, and 148.32 m²/g for N-g-CN/Fe3O4. These values demonstrate an increase in surface area upon the incorporation of heteroatom of nitrogen and Fe3O4, into the g-CN matrix, thus influence the photocatalytic performance. Under solar light exposure, the synthesized photocatalysts demonstrated photocatalytic activity with a degradation efficiency of 94.16 % within 120 min. Specifically, the N-g-CN/Fe3O4 (22.5 %) composites exhibited remarkable photocatalytic efficiency due to the narrow band gap energy between N-g-CN and Fe3O4, enhanced light absorption in the visible range, and effective charge carrier separation and transportation to the pollutants. N-g-CN/Fe3O4 (22.5 %) composites demonstrated good recyclability (five cycles), magnetic sustainability, and stability for the degradation of TC and emerging pollutants from wastewater using photocatalysts. Similarly, FGCN composites exhibited good recyclability (five cycles), magnetic retrievability, and stability for degrading organic and emerging pollutants from wastewater through photocatalysis. This efficiency can be attributed to the harmonious combination of nitrogen doping, refined surface area, and the natural heterojunction between N-g-CN and Fe3O4.