Activated carbon is one of the most extensively investigated electrode material for energy storage due to its cost effective, abundantly naturally, high stability and well developed pore structure. In the present work prepared MoS2 nano material decorated on the porous carbon's surface were synthesized via one step Sonication process. The hybrid composite material MoS2@WTC8 prepared at 3 different ratios, the best MoS2@WTC8-2 composite material. We report the specific capacitance 710 F/g at current density of 1 A/g in 3 electrode system. Moreover, both symmetric and asymmetrical supercapacitors fabricated using the optimized composite possessed high capacitance values with outstanding retention of cycling stability, confirming excellent electrochemical reversibility and durability. This work therefore proves that the hybrid material, MoS2@WTC8-2, is very promising for actuating supercapacitors in future advanced technologies related to eco-carbon materials.

Plastic waste presents a main environmental issue because of its volume and persistent nature. Electrocatalytic upcycling has evolved as an assuring strategy for plastic transforming into value-added chemicals (VACs) over mild conditions, offering low carbon emissions and high selectivity. In particular, the electrochemical polyethylene terephthalate (PET) upcycling extends a sustainable strategy to mitigate plastic pollution while generating VACs. This process involves depolymerizing PET into monomers as terephthalic acid and ethylene glycol, followed by selective electro-oxidation of EG into C1/C2 products such as formate, glycolate, and carbonate. This review discusses current progress in integrated electrochemical systems that couple PET hydrolysate oxidation with cathodic reactions like the hydrogen evolution reaction, nitrate and CO2 reduction reaction. These hybrid systems enable the coproduction of valuable compounds including hydrogen, ammonia, and formate, effectively valorizing dual waste streams. Key focus areas include mechanistic insights into electrocatalytic pathways, catalyst development, and process integration. Despite the progress, challenges remain in catalyst stability, product separation, and scalability. This review also addresses current limitations and outlines future research directions toward scalable, sustainable, and carbon-circular technologies for plastic recycling.

Flexible and high-performance sodium-ion storage systems are essential for next-generation energy technologies. Here, orthorhombic K(VO2)2(PO4) nanostructures were synthesized on carbon cloth through a controlled phosphorization process for 4 h (4KVOP-C). The 4KVOP-C electrode exhibited a fibrous network morphology, providing abundant active sites, short Na+ diffusion pathways, and strong contact with the conductive substrate. Moreover, its robust P-O bonds and open ion-diffusion channels enhanced its structural stability and charge transport. The 4KVOP-C electrode delivered outstanding electrochemical performance, with a high areal capacitance and excellent rate capability in a three-electrode configuration. The phosphate-stabilized vanadyl framework of KVOP enables delocalized charge redistribution across the V-O-P networks during Na adsorption, resulting in a higher quantum capacitance and density of states at the Fermi level. This electronic preconditioning underlies its superior areal capacitance, fast charge-discharge, and enhanced Na-ion accommodation compared with those of potassium-intercalated vanadium oxide. Moreover, a symmetric 4KVOP-C//4KVOP-C supercapacitor was assembled, which operated over a wide voltage window of 2.0 V, achieving an energy density of 50 & micro;W h cm-2 at a power density of 1980 & micro;W cm-2, along with excellent cycling stability. These results demonstrate that the fibrous K(VO2)2(PO4) nanostructures synthesized via optimized phosphorization exhibit excellent intrinsic electrochemical properties, making them potential electrode materials for flexible, high-energy-density and durable sodium-ion supercapacitors.

The development of efficient and durable electrocatalysts remains crucial for sustainable production of hydrogen via water electrolysis. Herein, we report a ruthenium-modified nickel-cobalt pyrophosphate [(NiCo)(P2O7)] catalyst (Ru-NCP) as a class leading oxygen evolution electrode under alkaline conditions and its application in anion exchange membrane water electrolysis (AEMWE). The NiCo2O4 precursor was transformed into a pyrophosphate framework through phosphidation, followed by Ru deposition and thermal reduction under Ar/H2. Structural analyses (XRD, Raman, TEM, XPS) confirmed the formation of the (NiCo)(P2O7) lattice and Ru-induced modulation of metal oxidation states. Electrochemical studies revealed an overpotential of 1.567 V at 100 mA cm-2 and stable operation at 400 mA cm-2 for 24 h in 1.0 M KOH. Integrated into an AEMWE, Ru-NCP achieved 1.6 A cm-2 at 4.5 V with extended durability. The superior performance arises from Ru-mediated electronic reconfiguration and enhanced active site accessibility within the pyrophosphate matrix.

Advanced supercapacitors, especially those made of hybrid materials, are the focus of increased research efforts due to the rising need for energy storage solutions. The goal of this work is to create a composite material MoS2@ HPC-P8 by synthesized by a simple sonication method and characterising. The successful integration of MoS2 with the porous carbon matrix was validated by structural and morphological investigations, such as XRD, FTRaman, FT-IR, SEM and N2-adsorption/desorption. In addition, the electrochemical studies evaluated through cyclic voltammetry, electrochemical impedance and galvanostatic charge-discharge measurements. Among the three prepared electrodes, the MoS2@HPC-P8-2 electrode exhibited best capacitive behavior, attaining a capacitance (Cs) of 354 F/g at 1 A/g. Furthermore, symmetric and asymmetric supercapacitor devices were fabricated using the composite material, demonstrating excellent cycling stability (5000 cycles 94% and 10,000 cycles 80%) and high energy (7.34 Wh/kg - 34 Wh/kg) and power densities (2.7 kW/kg - 2.3 kW/kg). These results imply that the MoS2@HPC-P8 composite has a great deal of promise for use in high-performance supercapacitors.

Carbon nanotubes (CNTs) have attracted sustained research interest as multifunctional electrode materials for electrochemical energy storage due to their outstanding electrical conductivity, large aspect ratio, mechanical strength, and tunable surface chemistry. This review provides a comprehensive overview of recent progress in CNT-based materials for energy storage, with a specific focus on aqueous electrolyte batteries (AEBs). Starting from the recent advancements in CNT synthesis techniques, we discuss strategies for controlling morphology, crystallinity, and scalability. The role of surface functionalization and heteroatom doping in tailoring interfacial chemistry and electrochemical activity is critically evaluated. Applications of CNT-based electrodes in supercapacitors and rechargeable batteries such as lithium, sodium, potassium, and zinc-ion systems are comprehensively reviewed, with highlighting the roles of CNTs as active materials, conductive additives, and structural scaffolds. Unlike the existing reviews that broadly survey energy storage applications, this work includes synthesis, structural design, and device-level performance with a specific focus on CNTs based aqueous electrolyte batteries. Key challenges including narrow voltage windows, side reactions, and electrolyte stability are discussed alongside emerging solutions enabled by CNT composite electrodes. Finally, current research gaps and future directions are identified to guide the rational design of CNT-based electrodes for next-generation safe and sustainable energy storage.

Herein, a palladium-decorated reduced cobalt-iron phosphate [Pd-CFP(R)], was synthesized through a controlled phosphidation-reduction route from spinel CoFe2O4 (CFO). The systematic transformation from the parent oxide to the mixed-metal phosphate phase was validated by X-ray diffraction and corroborated by structure-plane simulations. Morphological assessments through SEM and TEM revealed uniformly distributed nanostructures with minimal morphological distortion after Pd incorporation. The surface analysis confirmed the coexistence of redox couples (Co2+/Co3+ and Fe2+/Fe3+), while the emergence of metallic Pd0 states indicated successful surface reduction and electron density modulation. Electrochemical evaluations demonstrated that Pd-CFP(R) exhibits greater oxygen evolution reaction (OER) performance, achieving 100 mA cm- 2 at 1.494 V vs. RHE along with a Tafel slope of 36.3 mV dec- 1, surpassing both pristine CFO and reduced CFP(R). The increased activity is accredited to optimized charge transfer kinetics and improved active surface density, as supported by EIS and ECSA analyses. The Pd-CFP(R) maintained remarkable operational stability at 400 mA cm- 2 for 24 h and structural integrity post-stability. Integration into a single-cell Anion Exchange Membrane Water Electrolyzer (AEMWE) achieved robust cell operation in 1.0 M KOH at a flow rate of 5 mL min- 1, exhibiting minimal overpotential drift during 35 h ON/OFF durability testing. This study provides a rational pathway to design electronically modulated transition-metal phosphate frameworks for sustainable and durable AEM-based water electrolysis systems.

Exploring heterostructured multimetal oxides holds incredible potential to greatly boost supercapacitor (SC) performance through the facile integration of two distinct materials. The performance characteristics of these sophisticated electrode materials exceed those of conventional single counterparts. Herein, we present a hierarchical NiMoO4/CoMoO4 (NM/CM-O) heterostructure with a well-defined nanosheet-array architecture (NSAs). This facile structure was grown on a nickel foam framework, enabling its use as a battery-type electrode material. The cohesive architecture of the resulting material allows it to function as a binder-free SC electrode, exhibiting markedly enhanced electrochemical performance. This design optimizes the density of redox-active sites, enhances interfacial charge-transfer efficiency, and minimizes ion-diffusion distances. Furthermore, pronounced synergistic interactions between the two components, together with the involvement of multivalent ions, enhance electrochemical performance. Interestingly, the NM/CM-O heterostructure NSAs, functioning as a binder-free electrode, exhibit an impressive specific capacity of 704C/g at 1 A/g, surpassing that of the individual constituent electrodes. Moreover, a hybrid SC (HSC) was constructed using NM/CM-O and activated carbon (AC) as the positrode and negatrode, respectively. This NM/CM-O//AC HSC demonstrated impressive performance, achieving a power density of 20.3 kW/kg and an energy density of 76.4 Wh/kg. Notably, it exhibited excellent durability, experiencing only a 6.9% capacitance loss after enduring 20,000 charge/discharge cycles. The proposed investigation into the engineering of a multi-redox-active-site heterostructure is expected to enable substantial advances in renewable energy technologies.

In this work, Nb5+ doped CCTO ceramic with high dielectric constant (epsilon r) and a very low dielectric loss (tans) is reported. Powder XRD analysis confirmed the cubic perovskite structure and the Rietveld profile shows the goodness of fit below 2. The XPS analysis confirmed the presence of Ca 2p, La 3d, Cu 2p, Ti 2p, O 1 s, and C 1 s, all of which exhibited their expected oxidation states. The SEM micrographs revealed a grain size of 1.01 +/- 0.07 mu m for pure and 1.77 +/- 0.13 mu m for Nb5+doped CCTO. The Nb5+doped CCTO exhibited high epsilon r approximate to 1.26 x 105 at 50 Hz with low tans approximate to 0.85 at 1 kHz for 673 K in comparison with pure CCTO. The Nyquist plots established a deviation from Debye type relaxation with a negative temperature coefficient of resistance (NTCR) type behaviour.

Recovering electroactive materials from spent primary batteries and converting them into useful products is a crucial and interesting topic for solving many environmental issues. Therefore, in this present work, we recovered useful electroactive materials from spent zinc-carbon (Zn-C) primary cells and utilized them to develop lithium-ion supercapacitor electrodes. In this typical recycling process, the electroactive composite was recovered using a two-step process combining electrochemical exfoliation and sonochemical technique. The structure, morphology and composition of the electroactive composite were studied in detail to explore its feasible electrode properties. Furthermore, a supercapacitor was designed using the composite; it operated at a wide voltage window of 2.5 V in 1 M LiClO4/acetonitrile electrolyte and showed a maximum specific capacitance of 84 F g-1. Moreover, the supercapacitor exhibited a high specific energy of similar to 18.22 W h kg-1 with a maximum specific power of similar to 6387 W kg-1 and a stability of similar to 73% over 10 000 charge/discharge cycles at 1 A g-1. Besides, the fabricated supercapacitor demonstrated practical application potential and showed that the composite recycled from spent primary cells is viable for developing rechargeable energy storage devices.

A streamlined design for nanoarchitecture can substantially enhance the performance of battery-type electrodes, leading to advanced hybrid supercapacitors (HSCs) with improved redox properties. Metal-organic frameworks (MOFs) are promising for electrochemical...

Hybrid supercapacitors combining faradaic and non-faradaic electrodes offer a significant improvement in electrochemical performance. Enhancing the energy storage in hybrid supercapacitors requires the development of binder-free hierarchical nanostructures directly on electrode surfaces, using scalable and cost-effective fabrication methods. The present work develops a straightforward technique to deposit highly electroactive nickel sulfide (NiS) nanostructures uniformly on the nickel foam via the Successive Ionic Layer Adsorption and Reaction (SILAR) method at room temperature by optimizing the number of SILAR cycles. From the fabricated NiS electrodes, the electrode deposited for 30 cycles (N-30s) displayed a maximum areal capacity of 2.08C cm-2 at the 2 mA cm-2 current density in a 6M KOH aqueous electrolyte. Additionally, a hybrid-supercapacitor (H-SC) was assembled using N-30s and commercial activated carbon (CAC@Ni foam) as the positive electrode and the negative electrode respectively, which demonstrated a considerable specific capacitance of 47 F g-1 at 2 mA cm-2. Moreover, the H-SC displayed a specific energy of 14.58 Whkg-1 for 0.214 kWkg-1 specific power with an exceptional retention (92 %) after 10000 charge/discharge cycles. These results demonstrated a route to utilize the directly deposited NiS@Ni nanostructure as a feasible positive electrode material for energy storage devices.

Metal pyrophosphates compounds with high conductivity and excellent redox properties are promising electrode materials for sustainable energy storage. So, the binder-free 1D stacked 2D Na7V3(P2O7)(4) (NVPO) nanosheets were grown on a carbon fiber cloth (C) (NVPO@C) through a two-step hydrothermal process followed by phosphorization under controlled atmospheric conditions. The binder-free 350-NVPO@C electrode exhibits an emergent architecture of intertwined nanofibers stabilizing over 2D enlarged nanosheets, providing enhanced ion transport pathways, improved conductivity, and expanded electroactive areas to boost sodium ion storage efficiency. It achieves a maximum gravimetric capacitance of 362 F g(-1) (257 F cm(-3)) at 4 A g(-1) with an excellent rate capability of similar to 76 % in a 1 M NaClO4/acetonitrile. Theoretical calculations suggest that (P2O7)(4-) plays a vital role in enhancing structural stability, facilitating ion diffusion, modifying the electronic structure, and boosting the adsorption energy of Na+. A 350-NVPO@C-based symmetric device with a broad electrochemical voltage of 2 V, delivering a maximal gravimetric energy density of 39 Wh kg(-1) (25.5 Wh cm(-3)) at a minimal gravimetric power density of 2005 W kg(-1) (1311 W cm(-3)), while maintaining an excellent capacity retention of similar to 89 % over 10,000 consecutive GCDs at 5 A g(-1). These findings highlight NVPO@C nanosheets as highly efficient electrodes for next-generation energy storage.

The urgent global demand for sustainable hydrogen production has intensified the search for efficient and costeffective electrocatalysts for anion exchange membrane water electrolysis. Herein, spinel lanthanum ferrites incorporated with multiple transition metals at the A-site, with a fixed lanthanum concentration (0.05 M) at the B-site, were synthesized using the conventional solution combustion technique. These materials were explored as non-noble metal-based electrocatalysts for overall water splitting and Anion Exchange Membrane Water Electrolysis (AEM-WE). Five different compositions were prepared, each containing two equimolar transition metals (Co, Cu, Zn, Ni) in the A-site, and their performance in the Hydrogen Evolution Reaction (HER) and Oxygen Evolution Reaction (OER) was systematically evaluated. Among these, Co0.5Ni0.5La0.05Fe1.95O4 (CoNi-LFO) and Co0.5Cu0.5La0.05Fe1.95O4 (CoCu-LFO) demonstrated remarkable activity in 1 M KOH, achieving a current density of 100 mA cm- 2 at 1.55 V vs. RHE for OER and -0.18 V vs. RHE for HER, respectively. When combined in a twoelectrode system (CoNi-LFO || CoCu-LFO) for overall water splitting, the pair required a cell voltage of 1.63 V to reach the benchmark current density of 10 mA cm- 2. The system-maintained stability during a 48 h test at 200 mA cm- 2 with minimal degradation. Subsequently, a Membrane Electrode Assembly (MEA) with a large active area of 16 cm2 was fabricated using CoNi-LFO for OER and CoCu-LFO for HER. This MEA was integrated into an AEM-WE device, which demonstrated superior performance in 3 M KOH at a flow rate of 5 mL min- 1. The AEMWE device exhibited stable and consistent hydrogen production during long-term testing at 200 mA cm- 2 for 200 h with no observable degradation.

Engineering hybrid nanoarchitecture materials, which feature meticulously designed hierarchical frameworks and components, represents a highly effective approach to meeting the demanding performance requirements of supercapacitors (SCs). Herein, we present a simple and affordable anion exchange strategy to tailor a unique, multifaceted transition metal chalcogenide of MoS2 integrated with Co9S8 (CMS) nanohybrid hierarchical framework grown on a porous Ni-foam substrate, serving as a free-standing electrode for SC. It examines the effect of anion exchange processes on electrochemical performance, demonstrating significant enhancements in various metrics. The CMS nanohybrid material exhibits a hierarchical architecture along with outstanding intrinsic conductivity, which collectively enhances its electrochemical performance and ion/charge transfer efficiency. This improvement is attributed to the synergistic effects of the component, which facilitate more efficient electrochemical reactions and mitigate the volume expansion associated with charging and discharging. Interestingly, the CMS nanohybrid electrode exhibits an impressive specific capacitance of similar to 1325 F g(-1) at a current density of 1 A g(-1), along with a substantial rate capability of similar to 63.6 % at 20 A/g, significantly surpassing those of their hybrid metal oxide counterparts. Additionally, the hybrid supercapacitor comprising CMS and activated carbon achieved a specific capacitance of similar to 246 F g(-1) at a current density of 1 A g(-1), a maximum energy density of similar to 76.73 Wh kg(-1), and a power density of similar to 19.06 kW kg(-1), while maintaining similar to 91.7 % cycling stability after 12,000 cycles. Thus, this work could provide a framework for integrating advanced bimetallic chalcogenides to enhance energy storage performance.

The development of in situ spectroscopy methods has enabled detailed studies of the surface chemistry and structures of electrodes and/or electrocatalysts under active electrochemical conditions, providing real-time insights into reaction pathways at the electrode–electrolyte interface, which is mandatory for understanding electrochemical processes in energy devices. Key challenges in understanding the high electrochemical selectivity and activity of catalysts for energy reactions include measuring reaction kinetics, detecting changes in the chemical environment, identifying reaction intermediates, and linking material properties to device performance. This review examines the advanced utilities of various in situ and operando spectroscopic methods, such as Fourier transform infrared, Raman, X-ray absorption, and X-ray photoelectron spectroscopy, in the study of rechargeable lithium-ion batteries, supercapacitors, water-splitting (O2 and H2 evolution), and hybrid electrolysis with small molecule oxidation into hydrogen fuel and value-added chemical production. Emphasizing the significance of the various in situ/operando methods in optimizing catalyst design and improving energy storage and conversion efficiency and durability, we provide a systematic assessment of their roles in addressing major challenges in energy material research, summarizing their operational mechanisms, benefits, and limitations, and delivering guidance for future experimental strategies.

Exploring highly electroactive electrode materials with compatible nanostructures, tunable properties, and strong conductive networks is vital for supercapacitors (SCs). However, comprehending this complex area remains a significant challenge. In this work, we report the synthesis of a hierarchical NiCo2O4@NiMoO4 (NCO@NMO) hybrid nanoarchitecture utilizing a cost-effective hydrothermal approach and subsequent annealing. This is achieved through facile and scalable in situ fabrication techniques that yield an electrode material suitable for advanced high-energy hybrid supercapacitors (HSCs). The unique hybrid nanoarchitecture is engineered to provide an effective, open-porous framework that facilitates ion diffusion and enables rapid electron transport. The NCO@NMO hybrid nanoarchitecture electrode exhibits a battery-type redox mechanism, achieving a peak specific capacitance of 1984 F g-1 at a current density of 1 A g-1 in an aqueous electrolyte, surpassing the performance of its individual components. Enhanced electrochemical performance is achieved by increasing the density of electroactive sites and conductivity through surface modifications, thereby facilitating rapid redox kinetics. Notably, the fabricated HSC device, with a configuration of NCO@NMO//activated carbon, demonstrates an impressive power density of 42.56 kW kg-1, complemented by an energy density of 75.04 Wh kg-1, and exhibits excellent cyclic stability, retaining up to 89.62 +/- 1.19 % of its capacitance, even after 20,000 cycles. The high energy density and considerable cyclic stability are comparatively higher than those of conventional SCs and even approach the values of commercial batteries.

The synergistic interaction and strategic manipulation of electronic structures by incorporating metal ions into the host matrix have captivated research efforts for supercapacitors. This study presents an efficient strategy for synthesizing Cu‐ion‐incorporated NiCo2O4 (CNCO) nano/microarchitectures using a hydrothermal method followed by heat treatment. It establishes a clear link between variations in Cu content and their effects on material properties, which influence electrochemical performance. Optimizing the Cu content enhances ion transport and conductivity, while creating active sites for faster charge transfer. The porous framework boosts structural integrity and mass transport, reducing aggregation risks. Enhanced performance stems from synergistic interactions between Cu and the NCO matrix in the CNCO nano/microarchitecture. The experimental findings are further substantiated by computational analyses utilizing density functional theory (DFT) calculations. Impressively, the regulated CNCO electrode material exhibits a remarkable specific capacitance of 1301 F/g at 1 A/g and a rate capability of 81.3% at 20 A/g, significantly outperforming other CNCO variants. The optimized CNCO electrode material contributes to a high‐performance battery‐supercapacitor hybrid system, achieving an energy density of 61.36 Wh/kg at a power density of 1.18 kW/kg, with excellent cyclic stability. This system illuminates green and pink light‐emitting diodes.

Strategic design and synergistic interactions between the electrodes and electroactive materials profoundly influence the energy storage efficiency of supercapacitor devices. Herein, we present the interfacial engineering of CoMoS4-NiS2 with a well-defined construction of amorphous/crystalline heterophases deposited on carbon cloth using a hydrothermal technique. The optimal in-situ growth of CoMoS4- NiS2 @CFC boasts an impressive areal capacity of 1341 mC cm-2 and retains similar to 91 % capacity after 50 0 0 cycles, attributed to the synergy effect and improved conductivity of multi-metallic sulfide ions over the CFC substrate. Density functional theory (DFT) reveals the metallic nature of CoMoS4-NiS2 @CFC and favorable OH- ion adsorption energy of -4.35 eV, enhancing its charge storage capabilities. Furthermore, a hybrid supercapacitor (HSC) and Pouch HSC are assembled utilizing the CoMoS4-NiS2 @CFC as a positrode and marine waste jellyfish-derived AC as a negatrode with an aqueous electrolyte. The HSC and PHSC demonstrate superior specific energies of 51.99 and 58.4 W h kg-1, respectively, along with corresponding specific powers of 800 and 780 W kg-1, maintaining robust stability of similar to 90 % stability over 10 0 0 0 cycles. Additionally, the HSC and PHSC have successfully illuminated several light-emitting diodes (LEDs) demonstrating superior energy storage performance. This work advances the design of hetero-phase multi-metal sulfides, paving the way for high-performance supercapacitor devices. (c) 2025 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

The study focuses on the development of binary nanoalloys based on metal dichalcogenides (Sn30Se70, Ni30Te70) and quaternary nanoalloy (Ni15Sn15Se35Te35) using the melt quenching technique. The nanoalloys show extensive water splitting in fresh and real seawater. Sn30Se70-coated nickel foam achieved a benchmark current density of 349 mV for the oxygen evolution reaction (OER), while Ni15Sn15Se35Te35-coated nickel foam (NF) required only 185 mV for the hydrogen evolution reaction (HER) in 1 M KOH. The study also shows that a two-electrode system can achieve sustained total water splitting at higher current densities (1 A.cm(-2)). Modification with a CuSx layer over NF at the OER end facilitated faster kinetics and mitigated chlorine corrosion enabling direct seawater splitting at 1.26 V. Continuous direct splitting of seawater at 100 mA cm(-2) for 120 h required only 1.88 V, showing an efficiency of 92.9 % for H-2 production in real seawater.