Entropy-guided electrode design is a promising strategy for improving the redox-site diversity, charge-transfer kinetics, and cycling durability of pseudocapacitive oxides. Herein, a medium-entropy molybdate, (Co,Mn,Ni, Zn)MoO4, is integrated with carbon nanotubes to develop a high-performance supercapacitor electrode. The multication A-site configuration expands the accessible redox chemistry, while the MoO42- framework supports structural stability in alkaline electrolyte. The CNT network provides continuous conductive pathways, reduces polarization, and enhances utilization of disorder-generated redox sites. The optimized composite delivers 880 F g-1 at 2 A g-1 and retains 580 F g-1 at 10 A g-1 in a three-electrode configuration, with 83% capacitance retention after 10,000 cycles. A symmetric device operated at 1.2 V in 6 M KOH achieves an energy density of 23.2 Wh kg-1 at 1200 W kg-1, along with 89% capacitance retention and 98% coulombic efficiency during extended cycling. Kinetic analysis confirms a hybrid charge-storage mechanism dominated by surface-controlled processes with diffusion-assisted pseudocapacitive contribution. Machine-learning models based on voltage, current density, and cycle number enable early prediction of long-term stability. This study provides a devicerelevant framework combining entropy-engineered oxide design with data-guided lifetime optimization for durable supercapacitors.

Per- and polyfluoroalkyl substances (PFAS) “Forever Chemicals” pose a persistent threat to water resources because of the exceptional stability of CF bonds, the structural diversity of PFAS classes, and increasingly stringent drinking-water targets in the low ng/L range. Conventional technologies dominated by activated carbons and ion-exchange resins often struggle with selectivity, regeneration, and the efficient removal of short-chain, neutral, and zwitterionic PFAS. Metal-organic frameworks (MOFs) provide a distinctive remediation platform because metal-node coordination environments, linker chemistry, defect landscapes, and pore microenvironments can be engineered with molecular precision. This review develops a coordination-chemistry framework that connects PFAS molecular descriptors (headgroup identity, hydration, chain length, and precursor structures) to MOF design variables (Lewis acidity and coordinative unsaturation at nodes, linker electronics, pore topology, and fluorophilicity) to rationalize binding and selectivity beyond empirical capacity metrics. PFAS uptake is organized into four interacting modes: outer-sphere electrostatic association, inner-sphere node-headgroup coordination, anion exchange, and confinement-driven tail partitioning, clarifying why paradigms derived from PFOS and PFOA can fail for short-chain and non-ionic PFAS. We compare key MOF families while emphasizing competition from inorganic anions and natural organic matter, defect-mediated capacity-durability trade-offs, and the distinction between structural robustness and coordination robustness in realistic waters. Capture-to-destruction strategies using MOF-derived materials and hybrid photo- and electrochemical systems are assessed with attention to coordination-enabled activation requirements and rigorous transformation-product accounting. Finally, we outline translation priorities, including standardized testing, regeneration and life-cycle durability, and integration into continuous-flow architectures.

The rational integration of redox-active oxides with conductive two-dimensional materials provides an effective strategy for developing high-performance solid-state supercapacitors. In this study, a delaminated few-layer Ti3C2Tx MXene (Mx)-coupled Ruddlesden-Popper/spinel heteroarchitecture was designed by integrating La2NiO4 and Co3O4 with a conductive two-dimensional scaffold. This architecture was developed to overcome the poor electrical conductivity and sluggish interfacial charge transfer that commonly limit oxide-based electrodes, while simultaneously improving interfacial transport and structural accessibility. The La2NiO4-Co3O4 (LaNiCo) binary composite was first synthesized through microwave-assisted co-precipitation, followed by systematic incorporation of Mx to obtain a loading-dependent Mx1-Mx4 series. Among the prepared electrodes, Mx3-LaNiCo exhibited the best electrochemical performance, delivering 791.16 F/g at 10 mV/s and 751.60 F/g at 1.5 A/g, along with 86% capacitance retention after 15,000 cycles. Structural, microscopic, and spectroscopic analyses confirmed that Mx incorporation promoted grain refinement, strengthened oxide-oxide/MXene interfacial coupling, suppressed particle aggregation, and established continuous electron-transport pathways. In addition, Mx increased the BET surface area and facilitated the formation of mesoporous architecture. Based on this optimized electrode architecture, a symmetric solid-state supercapacitor was fabricated on woven carbon fiber by vacuum-assisted resin transfer molding (VARTM) using a PVA-Na2SO4 gel electrolyte. The resulting device achieved an energy density of 89.22 Wh/kg at a power density of 1050 W/kg and retained 73% of its capacitance with 92% coulombic efficiency after 50,000 cycles. These findings demonstrate viable materials and device engineering strategy for translating Mx-integrated oxide heterostructures into durable, high-energy solid-state supercapacitors.

A multifunctional nanocomposite consisting of halloysite nanotubes (Hal), carbon nanotubes (CNT), and polypyrrole (PPy) was synthesized via in situ oxidative polymerization for dual applications in desulfurization and energy storage. The resulting Hal-CNT-PPy hybrid featured a hierarchically porous structure with improved surface reactivity, conductivity, and mechanical stability. For adsorptive desulfurization, the composite achieved 84.96 % dibenzothiophene (DBT) removal under optimized conditions, with adsorption following pseudosecond-order kinetics and fitting the Langmuir isotherm (monolayer capacity: 69.84 mg/g). To optimize performance prediction, machine learning models nonlinear regression (NLR), support vector regression (SVR), and artificial neural networks (ANN) were applied. Among them, the ANN model demonstrated the highest accuracy and generalization across varying inputs. In parallel, electrochemical studies revealed superior energy storage performance, a symmetric two-electrode supercapacitor delivered 237.66F/g at 1 A/g with energy densities of 46.21 Wh/kg at 450 W/kg and 12.93 Wh/kg at 7,500 W/kg, retaining 79 % capacitance after 20,000 cycles. These findings highlight the synergistic design of Hal-CNT-PPy as a scalable, high-performance material platform for integrated environmental remediation and sustainable energy technologies.

Developing electrode materials with high electrochemical activity, rapid charge transport, and long-term stability remains a key challenge for advanced supercapacitor technologies. In this work, a series of BiVO4-polypyrrole (BV-PPy) composite electrodes was synthesized by gradually increasing the BiVO4 concentration within a conductive polypyrrole matrix via an in situ oxidative polymerization approach. The aim was to identify the optimized BiVO4 content that maximizes electrochemical activity for supercapacitor applications. Structural and spectroscopic analyses confirm the successful incorporation of BiVO4 within the conductive PPy matrix, forming a strongly coupled hybrid structure that promotes efficient electron transport and abundant electroactive sites. Among the prepared composites, the optimized B3V-PPy electrode exhibits superior electrochemical performance, delivering a high specific capacitance of 573Fg-1 at 1.5Ag-1 with good rate capability. Electrochemical impedance spectroscopy reveals reduced internal resistance and enhanced charge-transfer kinetics due to the synergistic interaction between BiVO4 nanoparticles and the PPy network. Kinetic analysis indicates a hybrid charge-storage mechanism, dominated by surface-controlled capacitive reactions with additional diffusion-controlled faradaic contributions. A symmetric solid-state supercapacitor assembled using the optimized B3V-PPy electrode and a PVA/Na2SO4 gel electrolyte operates stably within a 1.4V potential window, delivering an energy density of 69.83Whkg-1 at a power density of 1050Wkg-1. The device also demonstrates good durability with 71% capacitance retention after 15,000 cycles. The enhanced electrochemical performance is attributed to the optimized balance between the conductive PPy network and the redox-active BiVO4 phase, which facilitates rapid electron transport, efficient ion diffusion, and improved utilization of electroactive sites. These results demonstrate that tuning the BiVO4 concentration in the polypyrrole matrix is a promising strategy for designing high-performance hybrid electrodes for advanced solid-state supercapacitor applications.

A scalable method has been developed for synthesizing nitrogen-doped carbon-supported platinum nanoparticles. Fusarium oxysporum was utilized as reducing and stabilizing agent, and calcination was employed to produce the carbon support. The unique properties of Fusarium oxysporum facilitate the reduction of metal ions while preventing agglomeration and maintaining nanoparticle stability. An extensive investigation of the electrochemical supercapacitor and temperature-dependent dielectric properties of the nanoparticles demonstrates their suitability for supercapacitor applications. Electrochemical analysis showed N-doped C/Pt NPs with high specific capacitance, 482.77F/g at 2.0 A/g, retaining 94 % capacitance even under 20 A/g after 10,000 cycles. The symmetric supercapacitor device displayed 275F/g at 2 A/g, maintaining 61.10 Wh/kg energy density at 1000 W/kg power density, with similar to 92 % capacitance retention after 10,000 cycles. Dielectric properties of N-doped C/Pt NPs were analyzed at both ambient (300 K) and elevated (450 K) temperatures, revealing temperature-dependent characteristics and alternating current conductivity. At 0.75 MHz, the dielectric permittivity (epsilon') was measured at 31, with tangent loss at 2.01 and a.c. conductivity at 2.597 x 10(-3 O-1) m(-1). Increasing the frequency to 6.0 MHz resulted in a 2.38-fold rise in dielectric permittivity and a decrease in tangent loss to 0.77, demonstrating the temperature-sensitive nature of dielectric relaxation.

This study presents the development of a multifunctional perovskite-based nanocomposite designed to address environmental remediation and material reuse. A novel hybrid material, LaNi0.5Co0.5O3-γ/carbon nanotube (LNC/CNT), was synthesized and evaluated for its dual functionality: the removal of Sb(III) from aqueous solutions and its subsequent repurposing for energy storage applications. The LNC/CNT nanocomposite demonstrated outstanding adsorption performance, achieving a removal efficiency of 92.51 %. The adsorption process followed a pseudo-second-order kinetic model (R2 = 0.996) and was well described by the Langmuir isotherm, yielding a maximum adsorption capacity of 414.99 mg/g. Following Sb(III) adsorption, the spent material was thermally treated and transformed into LNC/CNT-SbOx, exhibiting promising potential for electrochemical reuse. In a symmetric supercapacitor configuration, the repurposed material delivered a high energy density of 70.33 Wh/kg at a power density of 1000 W/kg while maintaining 89 % of its initial capacitance after 13,000 charge-discharge cycles, indicating excellent long-term cycling stability. This work highlights a circular materials strategy that converts exhausted adsorbents into value-added functional materials, offering a sustainable and eco-friendly approach to pollutant removal and energy storage.

The electrochemical detection of cadmium (Cd(II)) is essential for environmental monitoring due to its high toxicity and persistence in aquatic ecosystems. This study presents a silver tungstate nanoparticle (Ag2WO4 NPs)modified glassy carbon electrode (GCE) as a sensitive and selective electrochemical sensor for Cd(II) detection. The strong interaction between Cd(II) ions and the active sites of Ag2WO4 NPs, combined with the material's redox-active properties, enhances electron transfer, resulting in improved conductivity and signal response. The sensor demonstrated excellent performance, with a broad linear detection range from 10 to 260 ppb and an impressive detection limit of 2.022 ppb, which is well below the permissible limits for drinking water set by regulatory agencies. The sensor's practical applicability was validated using real-world water samples, including tap water, groundwater and river water, with minimal interference from co-existing ions. The relative standard deviation (RSD) values ranged from 0.69 % to 6.59 %, confirming its reliability in complex environmental matrices. These results highlight the potential of Ag2WO4 NPs-based electrochemical sensors as cost-effective, reliable, and efficient tools for real-time monitoring of heavy metal contamination in diverse environmental conditions.

The depletion of fossil fuels and the growing demand for sustainable energy solutions have accelerated research into advanced energy storage technologies. Supercapacitors have gained prominence due to their remarkable power density, rapid charging capabilities, and extended cycle life, making them ideal candidates for addressing energy challenges. Vanadium oxide (V2O5), known for its versatile valence states, affordability, low toxicity, and broad voltage window, has emerged as a promising material for energy storage applications. This study presents a green synthesis approach to prepare pristine V2O5 and Fe-doped V2O5 (V1.9Fe0.1O5, V1.8Fe0.2O5, and V1.7Fe0.3O5) using Morus alba (mulberry) leaf extract as a natural reducing and stabilizing agent. This ecofriendly method offers a sustainable alternative to conventional synthesis routes while optimizing Fe doping to enhance the electrochemical performance of V2O5-based electrodes. The results revealed that Fe doping plays a crucial role in improving redox activity and maintaining the structural stability of the V2O5 lattice. Among the synthesized materials, V1.8Fe0.2O5 exhibited superior performance, achieving a specific capacitance of 719.25 F/ g at a current density of 2 A/g in a 1 M Na2SO4 electrolyte. This performance surpassed that of undoped V2O5 (604.17 F/g), V1.9Fe0.1O5 (647.32 F/g), and V1.7Fe0.3O5 (676.09 F/g), demonstrating the significance of optimized Fe content in balancing redox activity and structural integrity. Furthermore, a symmetric supercapacitor device fabricated with V1.8Fe0.2O5 delivered exceptional cycling stability, retaining 94 % of its initial capacitance after 10,000 cycles, and achieved an energy density of 49 Wh/kg at a power density of 957 W/kg. These findings underscore the potential of Fe-doped V2O5 as a highly efficient electrode material for next-generation super- capacitors, offering a sustainable and scalable solution to meet rising energy storage demands.

The bentonite chitosan polypyrrole (Bent-CS-PPy) composite was engineered as a multifunctional material with dual capabilities: the efficient adsorption of dibenzothiophene (DBT) from model fuel and application as an electrode in electrochemical energy storage systems. This hybrid composite leverages the layered morphology and cation-exchange capacity of bentonite, the hydrophilic and functional -OH and -NH2 groups of chitosan, and the redox-active, π-conjugated polymeric framework of polypyrrole, resulting in a porous, conductive, and chemically interactive matrix. In adsorptive desulfurization studies, the Bent-CS-PPy composite exhibited a DBT removal efficiency of 81.26 % under optimized conditions. The adsorption kinetics followed a pseudo-second-order model and fit the Langmuir isotherm, with a monolayer adsorption capacity of 33.71 mg/g. Machine learning (ML) algorithms including nonlinear regression (NLR), artificial neural networks (ANN), and support vector regression (SVR) were employed to predict DBT removal performance, with the ANN model demonstrating the highest predictive accuracy. Furthermore, the composite was evaluated as a symmetric supercapacitor electrode, delivering an energy density of 44.67 Wh/kg and a power density of 500 W/kg. Notably, it retained 73.44 % of its initial capacitance after 13,000 continuous charge-discharge cycles. These results underscore the potential of Bent-CS-PPy as a sustainable, dual-functional material for integrated environmental remediation and energy storage applications.

This study introduces a pioneering bimetallic metal-organic framework (VY-MOF) integrated with carbon nanotubes (CNTs) via a probe sonication-assisted hydrothermal synthesis, leveraging H4BTC as a tetrafunctional organic linker. The VY-MOF@CNT composite uniquely combines the high surface area and redox-active sites of the Y/V bimetallic system with the conductive CNT network, overcoming traditional limitations in charge transfer kinetics and structural stability. XRD, Raman, and XPS characterization confirms the formation of a crystalline VY-MOF matrix with tailored porosity and mixed oxidation states (V3+/V4+, Y3+), while SEM/EDS validates the homogeneous CNT dispersion, creating hierarchical ion diffusion pathways. Electrochemically, the VY-MOF@CNT electrode achieves a specific capacitance of 1661 F/g at 2 A/g surpassing monometallic Y-MOF (3.3x), V-MOF (2.5x), and pristine VY-MOF (1.66x) attributed to synergistic dual charge storage: electric double-layer capacitance (EDLC) from CNTs and pseudocapacitance from Y/V redox centers. Trasatti and Dunn's analyses quantify a hybrid mechanism (b-value = 0.67) with 68 % surface-controlled contributions, while the assembled symmetric supercapacitor (SSD) delivers an exceptional 60 Wh/kg energy density at 1200 W/kg, rivaling lithium-ion capacitors. Remarkably, the device retains 92 % capacitance after 10,000 cycles at 15 A/g, demonstrating unprecedented durability for MOF-based systems. These findings highlight the composite's robustness and superior electrochemical durability, underscoring its potential as a cutting-edge electrode material for next-generation energy storage technologies. This work demonstrates a pathway for enhancing supercapacitor performance and provides a framework for bimetallic MOF-based composites with improved electrochemical functionalities.

A novel strategy for addressing industrial wastewater and energy storage issues has been introduced by constructing a symmetric supercapacitor device using the adsorption of antimony (Sb(III)) from wastewater, facilitated by RGO-Au-Ag2O/PIn NCs heralding a new era of efficiency and sustainability. The room temperature mediated synthesis of RGO-Au-Ag2O/PIn NCs demonstrates exceptional efficacy in Sb(III) removal. Moreover, we developed a sustainable approach by repurposing spent Sb(III) adsorbed RGO-Au-Ag2O/PIn NCs for energy storage, thereby reducing secondary pollution. The RGO-Au-Ag2O/PIn NCs presented the maximum removal efficiency of similar to 90 % at 60 mg/L of initial Sb(III) concentration at pH 8 and 15 mg/25 mL. Experimental adsorption data of Sb(III) onto the RGO-Au-Ag2O/PIn NCs was well fitted with pseudo-second-order kinetic model and Langmuir adsorption isotherm model. Subsequently, the Sb-enriched waste adsorbent (RGO-Au-Ag2O/PIn@SbOx) was utilized to develop a symmetric supercapacitor device, which displayed an energy density of 40.66 Wh/kg alongside a power density of 1000 W/kg. Importantly, this device maintained 82 % capacitance retention even after 12,000 cycles. This research provides an effective method for repurposing exhausted adsorbents, potentially improving energy-efficient recycling of hazardous solid residues in an economical and environmentally friendly way.

Structural supercapacitors (SSCs) are poised to revolutionize energy storage in lightweight systems by integrating mechanical load-bearing and electrochemical functionality into a single device. However, a core challenge remains unresolved: simultaneously achieving a high mechanical stiffness and robust electrochemical performance. This Perspective presents a focused viewpoint on interface-dominated mechanisms that dictate the multifunctionality in SSCs. Advancements in carbon fiber surface activation, polymer electrolyte design, and nanomaterial interlayers are identified as promising pathways to decouple the mechanical electrochemical trade-off. Recent literature and experimental insights demonstrate that interface engineering at the fiber/electrolyte and electrode/separator interfaces governs ion transport, stress distribution, and energy retention. A strategic roadmap for scalable fabrication and performance optimization is outlined, positioning interface control as the linchpin of next-generation SSC technologies.

The development of multifunctional materials capable of addressing both environmental remediation and energy storage is essential for advancing sustainable technologies. In this study, La2Mo4O15/carbon nanotube (LaMo/ CNT) nanocomposites were prepared and investigated as adsorbent material for Sb(III) removal and highperformance supercapacitor electrodes. The nanocomposites demonstrated removal efficiency of 88.7 % for Sb (III), with adsorption kinetics following a pseudo-II order model. The adsorption performance was governed by synergistic interactions including electrostatic attraction, hydrogen bonding, and inner-sphere complexation. Machine learning models (ANN, NLR, and SVR) were employed to infer Sb(III) adsorption efficacy, with the ANN model showing superior predictive accuracy. High-resolution X-ray photoelectron spectroscopy revealed chemical state evolution of La, Mo, Sb, and O before and after Sb(III) adsorption and thermal activation. The appearance of distinct Sb 3d peaks confirmed successful immobilization, while post-activation spectral shifts indicated partial oxidation to Sb(V), consistent with Sb-O-M (M = La, Mo) coordination and enhanced redox activity. The Sb-adsorbed nanocomposites were repurposed as supercapacitor electrodes, delivering a specific capacitance of 824.44 F/g at 1.5 A/g and surpassing the performance of pristine LaMo/CNT (783.21 F/g). The assembled symmetric device retained 90.2 % capacitance after 15,000 cycles and achieved an energy density of 73.53 Wh/kg at 750 W/kg. This work proposes a sustainable waste-to-energy pathway by integrating machine learning, interfacial chemistry, and multifunctional design for environmental and energy applications.

This study investigates the synthesis of LaVO4 (LaVO), Co3O4-LaVO4 (Co-LaVO), and Co3O4-LaVO4/MXene (Co-LaVO/Mx) nanocomposites, focusing on optimizing the MXene concentration in Co-LaVO/Mx for high-performance supercapacitor electrodes. The optimal MXene concentration in Co-LaVO/Mx was identified and utilized to fabricate high-performance supercapacitor devices using the vacuum-assisted resin transfer molding (VARTM) technique. Among the tested compositions in a three-electrode system, the Co-LaVO-Mx3 nanocomposite exhibited the highest electrochemical performance, achieving an outstanding specific capacitance of 1287.80 F g-1 at a current density of 1 A g-1. This remarkable performance significantly surpasses that of LaVO (575.67 F g-1), Co-LaVO (610.66 F g-1), Co-LaVO/Mx1 (783.56 F g-1), and Co-LaVO/Mx5 (1196.45 F g-1), demonstrating the crucial role of optimized MXene concentration in improving charge storage, conductivity, and overall electrochemical efficiency. The optimized Co-LaVO/Mx3 nanocomposite was integrated onto woven carbon fibres (WCFs) and employed to fabricate high-performance solid-state supercapacitor devices using the VARTM technique. The resulting device demonstrated an impressive specific capacitance of 317.57 F g-1 at 2 A g-1 and achieved a remarkable energy density of 74.85 W h kg-1 at 1000 W kg-1. Furthermore, it exhibited exceptional cycling stability, retaining 71% of its initial capacitance after 50 000 cycles, highlighting its robustness and long-term operational reliability for advanced energy storage applications.

Traditional supercapacitors often rely on bulky enclosures that increase weight and reduce space efficiency, thereby limiting their suitability for compact and lightweight energy storage systems. Structural supercapacitors, which integrate energy storage functionality into load-bearing components, represent a promising approach for next-generation automotive and aerospace technologies. This study presents the synthesis and optimization of Ni (OH)2/V3S4 and graphene-incorporated Ni(OH)2/V3S4 ((Gr/Ni(OH)2/V3S4) nanocomposites for highperformance structural supercapacitor applications. The optimized nanocomposite, containing 3 wt% graphene (Gr3/Ni(OH)2/V3S4), exhibited an outstanding specific capacitance of 0.13 F/cm2 at a current density of 4.5 mA/cm2 in a three-electrode configuration. This enhanced performance is attributed to the synergistic effects among Ni(OH)2, V3S4 and graphene, which collectively improve electrical conductivity and increase the accessibility of electroactive sites. To evaluate its structural applicability, the Gr3/Ni(OH)2/V3S4 composite was coated onto woven carbon fiber (WCF) and incorporated into a structural supercapacitor device (SSD) using vacuum-assisted resin transfer molding (VARTM). The resulting SSD delivered a specific capacitance of 2.36 F/ cm2 at 16 mA/cm2 and maintained 72 % of its initial capacitance after 50,000 charge-discharge cycles at a high current density of 0.16 A/cm2. Furthermore, the device achieved a high energy density of 73.75 Wh/Kg at a power density of 1000 W/Kg, underscoring its strong potential for multifunctional energy storage. These results highlight the viability of Gr3/Ni(OH)2/V3S4-based structural supercapacitors as lightweight, high-performance energy storage solutions for advanced engineering applications.