Electrochemical behavior of CuO/rGO nanopellets for flexible supercapacitor,non-enzymatic glucose,and H2O2 sensing application

In the present article, graphene oxide (GO) sheets and monoclinic copper oxide (CuO) nanocrystals are connected with each other and result in the formation of CuO/rGO nanopellets, and these nanopellets synthesized using coprecipitation method. The nanopellet structured CuO/rGO composite on carbon cloth, which act as current collector exhibits specific capacitance of 188 F g^?1 at a current density of 0.2 A g^?1 and up to 96.3% capacity retention after 2000 charge-discharge cycles. It shows a maximum energy density of 7.32 Wh kg^?1 and power density of 53 W kg^?1. The glucose sensing characteristics of CuO/rGO nanopellet is investigated on carbon cloth and ITO substrate. It shows glucose sensitivity of 0.805 mA mM^?1 cm^?2 and 0.2982 mA mM^?1 cm^?2 for a bundle like structured CuO/rGO composite on carbon cloth and ITO substrate, respectively. Further H₂O₂ sensing is studied on ITO substrate, which manifests H₂O₂ sensitivity of 84.39 μA mM^?1 cm^?2. The results indicate that nanopellet structured CuO/rGO composite could be a promising electrode material for supercapacitor, glucose, and H₂O₂ sensor.     

Polypyrrole-wrapped NiCo2S4 nanoneedles as an electrode material for supercapacitor applications

In this study, dicobalt tetrasulfide (NiCo₂S₄) nanoneedles were successfully synthesized by a two-step hydrothermal method on nickel foam. A layer of polypyrrole (PPy) was further wrapped on the surface of the NiCo₂S₄ nanoneedles by in-situ polymerization. The obtained NiCo₂S₄@PPy composite was investigated for supercapacitor applications, which exhibited a capacitance of 1842.8 F g^?1 at 1 A g^?1. An asymmetric supercapacitor device fabricated with an activated carbon negative electrode and NiCo₂S₄@PPy positive electrodes exhibited an energy density of 41.2 Wh kg^?1 at 402.2 W kg^?1 with a high charge–discharge cycling stability (92.8% after 5000 cycles). These results demonstrate that NiCo₂S₄@PPy electrodes have broad application prospects as energy storage electrode materials.     

Simultaneously morphology and phase controlled synthesis of cobalt manganese hydroxides/reduced graphene oxide for high performance supercapacitor electrodes

Cobalt manganese hydroxides with well-defined nanowire morphology (CoMn-HW) is scalable fabricated by adjusting solution contents, Mn/Co ratio and alkaline species. To further improve the conductivity of CoMn-HW, GO is introduced during fabrication process and reduced to rGO according to the high temperature and alkali atmosphere. By optimizing the adding mass of rGO, CoMn-HW/rGO with sandwiched like structure is successfully synthesized for supercapacitor electrode. The composite delivers a high specific capacitance of 784 F g⁻¹ at current density of 0.5 A g⁻¹, good rate capability (84.2% capacitance retention after current density increase 10 times). Moreover, an asymmetric supercapacitor with CoMn-HW/rGO10 as the positive electrode and active carbon as the negative electrode, is assembled and delivers a maximum energy density of 38.3 Wh kg⁻¹ and power density of 8000 W kg⁻¹, representing its potential in energy storage and conversion systems.     

Promising electrode material of Fe3O4 nanoparticles decorated on V2O5 nanobelts for high-performance symmetric supercapacitors

Bundled V₂O₅ nanobelts decorated with Fe₃O₄ nanoparticles (F3V nanostructures) were successfully synthesized to develop a low-cost electrode material for energy storage applications. The synthesized samples were subjected to structural, morphological and electrochemical studies. The Fe₃O₄ nanoparticles decorated over bundled V₂O₅ nanobelts exhibited better electrochemical properties than the pristine Fe₃O₄ nanoparticles and V₂O₅ nanobelts. The electrochemical behavior of the fabricated electrodes was investigated in an electrolyte of 3 M KOH, demonstrated an exceptional specific capacity values of 750.1, 660.3, and 1519 F g^–1 for V₂O₅, Fe₃O₄, and F3V respectively at a current density of 15 A g^–1. The assembled F3V symmetric supercapacitor (SSC) device exhibited an excellent specific capacitance of 93 F g^–1 at a current density of 0.5 A g^–1, delivering energy and power densities of 13 Wh.kg^–1 and 1530 W kg^–1, respectively, and superior long-term cycling stability of ～84% capacity retention over 5000 galvanostatic charge–discharge cycles. These findings demonstrate the extraordinary electrochemical characteristics of the F3V nanostructures, indicating their potential use in energy storage applications.     

Development of bifunctional Mo doped ZnAl2O4 spinel nanorods array directly grown on carbon fiber for supercapacitor and OER application

Electrochemical energy storage and water splitting strategies may be greatly improved with proper structural design and doping techniques. In the present study, molybdenum-doped ZnAl₂O₄ loaded on carbon fiber (Mo–ZnAl₂O₄/CF) was fabricated via a simple hydrothermal synthetic approach. Due to its unique hierarchical nanostructures and enhanced electrical, structural topologies, Mo-doped ZnAl₂O₄ demonstrates exceptional supercapacitor performance and electrocatalytic oxygen evolution reaction activity. The Mo-doped ZnAl₂O₄ electrode material exhibited 1477.63 F g^?1 specific capacitance, 46.57 Wh Kg^?1 specific energy and specific power of 476.4 W kg^?1 at 1 A g^?1. After 5000 cycles, the pseudo supercapacitor retains 97.46% of its capacitance and displays stable behavior over 50 h. During the OER reaction, the Mo–ZnAl₂O₄/CF as an electrocatalyst rapidly self-reconstructs, resulting in many oxygen vacancies, and causes a lower 38 mV dec^?1 Tafel slope and overpotential potential of 255 mV to achieved 10 mA cm^?2 current flow and responsible for the excellent stability of the electrocatalyst. These findings suggest that multifunctional materials based electrode for electrical energy conversion and storage become more efficient and stable by using Mo for doping to generate porous hierarchical structures and local amorphous phases.     

A new strategy for porous carbon synthesis: Starch hydrogel as a carbon source for Co3O4@C supercapacitor electrodes

A novel Co₃O₄@C composite with a three-dimensional (3D) interconnected network morphology was successfully fabricated by anchoring cobalt oxide nanocrystals onto porous carbon originating from starch hydrogels via freeze drying, precarbonization and thermal treatment in an aqueous system. Benefiting from unique structural features, the optimized electrode delivers an excellent capacitance of 1314.0 F g^?1 (1 A g^?1) and outstanding durability in terms of capacity preservation (93.5% over 10,000 cycles). In addition, an asymmetric supercapacitor consisting of DF-2 and active carbon exhibits an energy density of 149.1 Wh?kg^?1 at 800 W kg^?1 while maintaining great stability. The observed excellent performance is attributed to the unique 3D network, good conductivity and high surface-to-volumetric ratio of the carbon skeleton derived from the starch gel, which has wide scope for applications.     

Highly porous metal organic framework derived NiO hollow spheres and flowers for oxygen evolution reaction and supercapacitors

In this study, metal-organic-framework (MOF) derived porous NiO hollow spheres and flowers were obtained using facile solvothermal synthesis and heat treatment. After pyrolyzing, the flower like and hollow spherical like morphology of NiO nanoparticles was successfully inherited from the initial MOF-based templates. The electrochemical studies demonstrated that the porous NiO hallow spheres unveiled a better supercapacitive performance (specific capacitance (C_s) = 1058 F g^?1 at current density (j) = 2 A g^?1) and oxygen evolution reaction (OER) catalytic activity (overpotential (?) = 323 mV) compared to porous NiO flowers (C_s = 857 F g^?1 at j = 2 A g^?1 and ? = 346 mV). Moreover, excellent capacity retention of over 93% was obtained in porous NiO-hs nanoparticles even after 5000 cycles. The fabricated NiO//Fe₂O₃ asymmetric supercapacitor delivered an energy density (E) of 35.75 W h Kg^?1 under power density (P) of 780 W kg^?1 and showed promising stability over 3000 cycles. Considering the ease of preparation and high catalytic activity and supercapacitive performance, these prous NiO hallow structures can be considered as a potential electrode material for next generation energy storage devices and OER catalysts.     

Cavity-like hierarchical architecture of WS2/α-NiMoO4 electrodes for supercapacitor application

In this study, we fabricated a nano/micro cavity-like hierarchical architecture of WS₂/α-NiMoO₄ composite using microwave hydrothermal and calcination processes. The composite was characterized by X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, elemental mapping, and X-ray photoelectron spectroscopy. The electrochemical measurements of the WS₂/α-NiMoO₄ composite electrode for application in supercapacitors (SCs) were performed through cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The WS₂/α-NiMoO₄ nanocomposite exhibited a specific capacity of 460 F g^-1 at 1 A g^-1 current density and a capacitor retention of 92% after 2000 cycles. However, α-NiMoO₄ spherical nanoparticles had a specific capacity of 231 F g^-1 at 1 A g^-1 current density and capacitor retention of 73% after 2000 cycles. The excellent specific area, formation of cavity-like structures, increase in pore size, superior electrical conductivity, and robust stability of WS₂/α-NiMoO₄ enhanced the effectiveness of the electrode composite material for supercapacitor application.     

Growth of yolk-shell CuCo2S4 on NiO nanosheets for high-performance flexible supercapacitors

A poor electrical conductivity and short cycle life limits the wide application of transition metal oxides in energy storage applications. In this study, yolk-shell structured CuCo₂S₄ was grown on NiO nanosheets (NiO@CuCo₂S₄) via a hydrothermal method and vulcanization, which combined the synergistic interactions between Ni, Co, and Cu. The effect of varying the amount of the vulcanizing agent (thiourea) on the electrochemical performance of NiO@CuCo₂S₄ was also investigated. Moreover, the amount of thiourea not only tuned the morphology of the composite, but significantly influenced its electrochemical performance. When the Cu²⁺: Co²⁺: thiourea molar ratio in the precursor solution was 1:2:6, the obtained NiO@CuCo₂S₄ exhibited the best electrochemical performance of the various systems examined, with a specific capacitance of 1658 F g^?1 being achieved at 1 A g^?1. Density functional theory calculations further confirmed the excellent synergistic effect between NiO and CuCo₂S₄. In addition, the asymmetric supercapacitor composed of a NiO@CuCo₂S₄ positive electrode reached an ultrahigh energy density of 73 Wh kg^?1 at a power density of 802 W kg^?1, as well as excellent cycling stability (i.e., 91% capacitance retention after 5000 cycles). These results suggest that NiO@CuCo₂S₄ is a promising candidate for use in energy storage applications.     

Ultra-high specific capacitance of self-doped 3D hierarchical porous turtle shell-derived activated carbon for high-performance supercapacitors

The turtle shell of biomass waste is used as raw material, and the natural inorganic salt contained in it is used as a salt template in combination with a chemical activation method to successfully prepare a high-performance activated carbon with hierarchical porous structure. The role of hydroxyapatite (HAP) and KOH in different stages of preparation was investigated. The prepared turtle shell-derived activated carbon (TSHC-5) has a well-developed honeycomb pore structure, which gives it a high specific surface area (SSA) of 2828 m² g^?1 with a pore volume of 1.91 cm³ g^?1. The excellent hierarchical porous structure and high heteroatom content (O 6.88%, N 5.64%) allow it to have an ultra-high specific capacitance of 727.9 F g^?1 at 0.5 A g^?1 with 92.27% of capacitance retention even after 10,000 cycles. Excitingly, the symmetric supercapacitor assembled from TSHC-5 activated carbon exhibits excellent energy density and cycling stability in a 1 M Na₂SO₄ aqueous solution. The energy density is 45.1 Wh·kg^?1 at a power density of 450 W kg^?1, with 92.05% capacitance retention after 10,000 cycles. Therefore, turtle shell-derived activated carbon is extremely competitive in sustainable new green supercapacitor electrode materials.     

One-pot facile synthesis and electrochemical evaluation of selenium enriched cobalt selenide nanotube for supercapacitor application

The present study emulates a one-pot facile synthesis of selenium-enriched CoSe nanotube using a chemical bath deposition (CBD) procedure. Schematic incorporation of 3D Ni foam current collectors as substrates for the growth of CoSe–Se nanotubes helped us achieve a binder-less thin film coating. The controlled synthesis of CoSe–Se nanotube was carried out by optimizing the temperature and time of the deposition. CoSe–Se nanotubes were grown on a porous Ni foam substrate using lithium chloride as a shape directing agent. The study found that the one dimensional structure of the nanotubes with porous nature results in an uninterrupted network of electroactive sites. Due to the superior conductivity, the as-fabricated material exhibited excellent rate capability and a higher degree of electrolyte ion diffusion across the CoSe–Se crystal structure. The CoSe–Se@Ni foam electrodes exhibited a specific capacitance of 1750.81 F g^?1 at 1 A g^?1. The electrode exhibited excellent cycling stability and showed a capacitance retention of 95% after 4000 charge-discharge cycles. Finally, an asymmetric supercapacitor (ASC) device was fabricated with the as-synthesized CoSe–Se@Ni foam electrode as the cathode, activated carbon@Ni foam electrode as the anode, and a thin filter paper separator soaked in 1 M aqueous KOH electrolyte solution. The ASC device showed a specific capacitance value of 106.73 F g^?1 at 0.5 A g^?1, and achieved an energy density of 37.94 Wh kg^?1 at a power density of 475.30 W kg^?1. The ASC device was utilized in an extended potential window of 1.6 V. The fabricated device displayed exceptional cycling stability with a capacitance retention of 93% after 5000 charge-discharge cycles.     

Promising carbon nanosheets decorated by self-assembled MoO2 nanoparticles: Controllable synthesis,boosting performance and application in symmetric coin cell supercapacitors

A composite containing self-assembled MoO₂ nanoparticles and functional carbon nanosheets was obtained via a facile and controllable strategy. Two-dimensional functional carbon nanosheets as matrices have close contact with MoO₂ nanoparticles, which assists in the improvement of electronic conductivity, provides efficient pathways and accelerates electron transfer. The carbon nanosheets have functional groups on the surface, which could serve as the nucleation sites for MoO₂. The MC-0.12 composite shows optimal specific capacitance (190.9 F g^-1 at 1 A g^-1) and excellent cycle stability between monomers and composites with different constituents. The assembled symmetrical coin cell supercapacitor using MC-0.12 possesses the maximum energy density of 10.3 Wh kg^-1 at a power density of 378 W kg^-1 and still maintains the energy density of 7.9 Wh kg^-1 at 1682 W kg^-1 with a larger potential window. The capacitance retention (92%) of the assembled device is maintained after 2000 cycles, showing outstanding cycle life. Therefore, the integration of self-assembled MoO₂ nanoparticles with 2D functional carbon nanosheets provides the composite superior electrochemical performance for supercapacitor applications.     

Self-standing manganese dioxide/graphene carbon nanotubes film electrode for symmetric supercapacitor with high energy density and superior long cycling stability

The low capacitance utilization and capacitance fading of manganese dioxide (MnO₂) is mainly due to poor electro-conductivity and irreversible phase transform. This work proposes a new method of designing hierarchical and binder-free electrode based on MnO₂ material for stable supercapacitor with high specific capacitance. Herein, we fabricated the self-standing electrode of MnO₂ on nitrogen-doped graphene and single wall carbon nanotubes (SWCNTs) self-standing film (NGCF) by electrochemical deposition. As a result, as-prepared MnO₂/NGCF cathode showed excellent electrochemical performance of 489.7 F g^-1 at 1 A g^-1. Assembled symmetric aqueous supercapacitor (SC) manifests high voltage of 2.4 V and presents excellent high energy density of 106.7 Wh kg^-1 at 1200 W kg^-1 and outstanding long-life stability without no decay after 10 000 charge-discharge circuits. This work proposes a new view of designing hierarchical and binder-free electrode with high energy density and long cycling stability based on MnO₂ material for stable symmetric supercapacitor.     

Al-doping driven electronic structure of α-NiS hollow spheres modified by rGO as high-rate electrode for quasi-solid-state capacitor

Developing an optimized electronic structure of α-NiS electrode material is critical for its high-rate electrochemical performance of quasi-solid-state capacitor. Herein, Al³⁺ have been doped into α-NiS lattice and the reduced graphene oxide (rGO) is employed to modify Al-doping α-NiS, to alleviate the low-mobility charge of α-NiS. The electronic structure and electrochemical properties of α-NiS hollow spheres induced by Al-doping and rGO modification are investigated, both experimental characterization and theoretical results confirm Al-doping affect the electronic structure and electrochemical performance of α-NiS hollow spheres. In the composite of Al-doping α-NiS and rGO (named as Al_xNi_1-xS/rGO), the doped heteroatom improves the intrinsic electronic structure of α-NiS and the rGO provides a good electric conducting network, leading to an enhanced electrochemical performance of α-NiS as high-rate electrode material. After evaluation, the optimized Al_0.2Ni_0.8S/rGO composite shows a superior reversible capacity of 1096 C g^?1 at 2 A g^?1, and retains a capability of 471 C g^?1 at a high-rate of 30 A g^?1. Moreover, an asymmetric quasi-solid-state hybrid capacitors assembled by Al_0.2Ni_0.8S/rGO and activated carbon presents a high energy density of 30.6 Wh kg^?1. This work provides a foundational strategy for the modification of α-NiS through Al-doping and combining with rGO, which has a positive effect on α-NiS electrode material in quasi-solid-state hybrid capacitors.     

Electrophoretic co-deposition of Bi2O3–multiwalled carbon nanotubes coating as supercapacitor electrode

Nafion is suggested as an efficient assistant in preparing supercapacitor by employing nanoparticles. In this work, using a bi-additive of 0.10-mM NaOH + 0.10 g L⁻¹ Nafion, Nafion-assisted electrophoretic co-deposition of Bi₂O₃–multiwalled carbon nanotubes (MWCNTs) coating is successfully realized in ethanol solvent. The capacitance performances of the electrophoretic coatings in 6.0-M KOH electrolyte are investigated by cyclic voltammetry and galvanostatic charge–discharge techniques. Comparing with Bi₂O₃ coating prepared with electrophoretic deposition (EPD) by employing other additive (such as polyethyleneimine), the Bi₂O₃ coating prepared by Nafion-assisted EPD shows a better capacitance performance. Benefiting from the improvement in coating conductivity caused by MWCNTs, with a small additional amount of 4.0 wt.%, the Bi₂O₃–MWCNTs coating exhibits an amazing 164% increase of mass-specific capacitance (473 F g⁻¹ at the current density of 1.0 A g⁻¹) in comparison with pure Bi₂O₃ coating (179 F g⁻¹ at the current density of 1.0 A g⁻¹). The cyclic stability test exhibits excellent capacitance retention of 88.7% over 3000 cycles at a constant current density of 10.0 A g⁻¹. This work combines the advantages of MWCNTs, Nafion, and EPD to provide a facile route for preparing Bi₂O₃-based coating as a high-performance supercapacitor electrode.     

V2O5 nanosheets assembled on 3D carbon fiber felt as a free-standing electrode for flexible asymmetric supercapacitor with remarkable energy density

As an emerging energy storage device, supercapacitor is widely investigated owing to its excellent capability, quick charge-discharge and tremendous cycle life. The operation potential window, energy density and mass loading of supercapacitor must be taken into deep consideration for its practical application. In this work, an outstanding electrode based on CFF@V₂O₅ nanosheets was prepared. Then a free-standing asymmetric supercapacitor with CFF@V₂O₅ composite as positive electrode and CFF@AC as negative electrode was assembled. Owing to the functional groups produced on CFF after the activation, V₂O₅ nanosheets was immobilized. The composite exhibits remarkable specific capabilities of 1465 mF cm^?2 (492 F g^?1). The energy density of the assembled free-standing asymmetric supercapacitor achieves 0.928 mWh cm^?3 when the power density is 17.5 mW cm^?3. After 6000 charging-discharging cycles as under normal, bended and anti-bended conditions for respective 2000 cycles, the device retains 89.7% of the initial capacitance, exhibiting fascinating cycle stabilization. Finally, two devices linked series can lighten a LED of 1.8 V for 2 min after charging for 2.5 min, which is inspiring for the practical application and production of self-supporting asymmetric supercapacitors.     

Synthesis of rGO/nanoclay/PVK nanocomposites,electrochemical performances of supercapacitors

ABSTRACT

In this study, graphene oxide (GO) was chemically reacted with sodium borohydride (NaBH₄) to form reduced graphene oxide (rGO). rGO, Montmorillonite nanoclay, and polyvinylcarbazole (PVK) were used to form a ternary nanocomposite via chemical reaction. These nanocomposite qualities were described via scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy-attenuated transmission reflectance (FTIR-ATR). In addition, these materials were used in supercapacitor device as an active material to test electrochemical performances via cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). The rGO/nanoclay/PVK nanocomposite shows significantly improved specific capacitance (C_sp = 168.64 Fg^?1) compared to that of rGO (C_sp = 63.26 Fg^?1) at the scan rate of 10 mVs^?1 by CV method. The enhanced capacitance results in high power density (P = 5522.6 Wkg^?1) and energy density (E = 28.84 Whkg^?1) capabilities of the rGO/nanoclay/PVK nanocomposite material. The addition of nanoclay and PVK increased the specific capacitance of rGO material due to a dopant effect for supercapacitor studies. Ragone plots were drawn to observe energy and power density of supercapacitor devices. The C_sp of rGO/nanoclay/PVK nanocomposite has only 86.4% of initial capacitance for charge/discharge performances obtained by CV method for 5000 cycles.     

Holey graphene interpenetrating networks for boosting high-capacitive Co3O4 electrodes via an electrophoretic deposition process

A composite of Co₃O₄/holey graphene (Co₃O₄/HG) was prepared via a facile hydrothermal route, and was then processed into an electrode by an electrophoretic deposition process. Holey graphene (HG) wrapped Co₃O₄ to form a 3D skeleton network, thereby providing high electrical conductivity, and the holes in HG could further shorten the electrolyte ion diffusion pathway. Therefore, by adjusting the mass ratio of Co₃O₄ to HG, the Co₃O₄/HG composite afforded an enhanced capacitance of 2714 F g⁻¹ (at a current density of 1 A g⁻¹), which is 20 times higher than that of pure Co₃O₄. To further explore the practical applications of Co₃O₄/HG, a symmetric supercapacitor employing Co₃O₄/HG was fabricated. The supercapacitor functioned stably at potentials up to 1.2 V, with an enhanced energy density of 165 Wh kg⁻¹ and a high power density of 0.6 kW kg⁻¹ at 1 A g⁻¹.     

NiFe-NiFe2O4/rGO composites: Controlled preparation and superior lithium storage properties

Binary transition-metal oxides with spinel structure have great potential as advanced anode materials for lithium-ion batteries (LIBs). Herein, NiFe-NiFe₂O₄/ reduced graphene oxide (rGO) composites are obtained via a facile cyanometallic framework precursor strategy to improve the lithium storage performance of NiFe₂O₄. In the composites, NiFe-NiFe₂O₄ nanoparticles with adjustable mass ratios of NiFe₂O₄ to NiFe alloy are homogeneously deposited on rGO sheets. As anode material for LIBs, the optimized NiFe-NiFe₂O₄/rGO composite displays remarkably enhanced lithium storage performance with an initial specific capacity as high as 1362 mAh g⁻¹ at 0.1 A g⁻¹ and a decent capacity retention of ca. 80% after 130 cycles. Besides, the composite delivers a reversible capacity of 550 mAh g⁻¹ at 1 A g⁻¹ after 300 cycles. During the charge–discharge cycles, the aggregation of the NiFe-NiFe₂O₄ nanoparticles and the structural collapse of the electrode can be well alleviated by rGO sheets. Moreover, the conductivity of the electrode can be significantly improved by the well-conductive NiFe alloy and rGO sheets. All these contribute to the improved lithium storage performance of NiFe-NiFe₂O₄/rGO composites.     

Supercapacitive properties,optical band gap,and photoluminescence of CeO2–ZnO nanocomposites prepared by eco-friendly green and citrate sol-gel methods: A comparative study

CeO₂–ZnO nanocomposite was synthesized using a cost-effective and environmentally friendly green method utilizing a natural extract of Hibiscus Sabdariffa L. The structural parameters, morphology, optical, and supercapacitive properties of a novel green sol-gel synthesized CeO₂–ZnO nanocomposite (CZO-g) were compared with those of a citrate sol-gel auto-combustion derived nanocomposite (CZO-s). XRD confirmed the formation of cubic and wurtzite hexagonal binary phases, and CZO-g exhibited better crystallinity than CZO-s. ZnO incorporation inhibits the accumulation of CeO₂ semispherical NPs, as demonstrated by FESEM images. DRS and PL emission measurements confirmed that the optical band gap of nanocomposites was widened. CV, GCD and EIS measurements were used to determine the electrochemical supercapacitive behavior of nanomaterials deposited on Ni Foams in a 3 M KOH electrolyte. At a current density of 1 A g^?1, CZO-g exhibited significantly greater specific capacitance (431 F g^?1) than CZO-s and CeO₂-g. Furthermore, CZO-g retained 89.4% of its initial capacitance after 3000 cycles at a high current density of 7 A g^?1, indicating that it could be a promising candidate for a high-performance supercapacitor.