Nanocomposite Electrode Materials Research Articles

Fabrication of enhanced electrochemical AlBiO3/g-CN nanocomposite electrode material via hydrothermal approach for supercapacitor applications

The fundamental discrepancy in energy produced from renewable sources indicates that there is a persistent mismatch between the supply and demand of energy. Researching and developing appropriate materials for employing energy-storing devices is an efficient approach to resolving this recurring issue. Using a hydrothermal preparation technique, AlBiO3 and AlBiO3/g-CN nanocomposites are produced in this work. Galvanostatic charge/discharge (GCD) analysis at 1 A g−1 were used to determine the specific capacitance (Cs) value for AlBiO3 and AlBiO3/g-CN which were 888 and 1508 F g−1, respectively. Over 10000th cycles, the AlBiO3 and AlBiO3/g-CN showed outstanding performance and outstanding cycling stability. The synergistic association between AlBiO3 and g-CN generated higher specific surface area (SSA) and extra active spots for higher charge transfer with less impedance. The outcomes of the electrochemical investigation exposed that the AlBiO3/g-CN composites architecture performed more effectively than the AlBiO3, suggesting that it is useful structure for energy-storage devices. Further, symmetric investigation was also confirmed that AlBiO3/g-CN nanocomposite promising electrode material for practical application.

Enhanced supercapacitive performance of FeAl2O4/g-CN nanocomposite for advanced energy storage systems

The innovation of nanomaterials for supercapacitors (SCs) presents a potentially viable solution to the energy crisis arising from our excessive dependence on fossil fuels. The present study demonstrated the hydrothermal synthesis of an environmentally sustainable and economical FeAl2O4 nanomaterial grafted on graphitic carbon nitride (g-CN) for supercapacitor applications. This study aimed to assess the supercapacitive capabilities of nanocomposite electrode material via various electrochemical tests. Upon investigation, it was discovered that FeAl2O4/g-CN nanocomposite material demonstrated a remarkable specific capacitance (1049 F g−1), energy density (29 Wh kg−1) and power density (223 W kg−1). Furthermore, the inclusion of g-CN nanosheets into the FeAl2O4/g-CN nanocomposite which increased surface area (SAA, 46 m2 g-1), leading to a decrease in charge transfer resistance by 0.73 Ω. The enhanced electrochemical performance was attributed to many factors, including an increased SAA, greater number of active regions and a nitrogen-rich structure that facilitates rapid ion adsorption. The FeAl2O4/g-CN nanocomposite exhibited a robust pseudocapacitive characteristic and demonstrated exceptional conduction, leading to a significantly enhanced cyclic stability endurance of 40 h. Hence, the synergistic behavior of FeAl2O4/g-CN nanocomposite results in its remarkable efficiency as a proactive electrode material for energy storage purposes.

Facile sonication synthesis of MnAl2O4/ZnO nanocomposite as an advanced electrode material for supercapacitor applications

Present studies on maintaining, effective energy providers and storage systems have developed because of problems with energy limitations, fossil fuel depletion and pollution. Spinel oxide nanocomposite electrode material is a superior remedy for supercapacitors (SCs). Herein, we synthesized MnAl2O4 and MnAl2O4/ZnO nanocomposites using the sonication method for energy storage devices. The manufactured material’s morphology, interfacial area and structural features were determined using scanning electron microscopy (SEM), Brunauer Teller Emmett analyses (BET) and X-ray diffraction (XRD), respectively. The crystalline nature of MnAl2O4 and MnAl2O4/ZnO nanosheets was observed by the XRD analysis. The electrochemical performance of the manufactured material was determined utilizing nickel foam (NF) as a conductive surface and 2.0 M KOH electrolyte, galvanostatic charging-discharging (GCD), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) study. Electrochemical outcomes showed that MnAl2O4/ZnO nanocomposite exhibits specific capacitance (Cs) of 1490.07 F/g at 1.0 A/g with high cyclic stability over 5000th cycles. Furthermore, an energy and power density of 55.96 Wh/kg and 260 W/Kg, correspondingly, were exhibited by MnAl2O4/ZnO nanocomposite pseudocapacitors. Compared to MnAl2O4 (0.47 Ω) the charge transfer resistance (Rct) value for MnAl2O4/ZnO (0.12 Ω) was smaller calculated via Nyquist plot and exhibited steady behaviour for 50 h. The outstanding potential of the electrode material MnAl2O4/ZnO was highlighted in this work, along with a novel method for producing multi-element composite materials at a reasonable cost and with excellent performance that could find use in a variety of supercapacitor and upcoming energy storage applications.

Nanoscale CdS enwrapped zeolite-like Zn-MOF nanocomposite for advanced energy storage systems

With reference to the promising characteristics of metal–organic frameworks (MOFs) and the contributions of nanoparticles (NPs) to their electrochemical activities, the hybrid MOF built with metal sulphides has garnered a lot of attention, primarily as electrode materials in energy storage devices. The polyhedral-shaped CdS enwrapped zeolitic imidazolate framework-8 (ZIF-8) nanocomposites have been prepared by in-situ chemical synthesis. The electrochemical performance was evaluated in 6 M KOH electrolyte, achieving a specific capacitance of 1063.48 Fg−1 at 5 mV/s. The nanocomposite electrode material exhibits good cyclic stability, with 82.32 % (6 M KOH) and 85.91 % (redox additive electrolyte) capacity retention after 6000 cycles at 5 A/g. The energy and power density of the asymmetric supercapacitor were found to be 2.81 Wh/kg and 1785.71 W/kg, respectively.

Synthesis of Niobium Pentoxide and Its Reduced Graphene Oxide Nanocomposite for Enhanced Supercapacitor Applications

Synthesis of Niobium Pentoxide and Its Reduced Graphene Oxide Nanocomposite for Enhanced Supercapacitor Applications

Designing of high performance MoS2@VZnS//AC hybrid battery supercapacitor device for the electrochemical energy storage and glucose detection

Due to their high conductive properties and superior specific capacitance, metal sulfides exhibit remarkable electrical conductivity. Transition metal dichalcogenides (TMDs) are regarded ideal options for energy harvesting devices due to their unique 2D arrangement and remarkable electrochemical properties. In this work, the typical exfoliation method (tip sonication method) was used to synthesize the molybdenum disulfide (MoS2). By using the hydrothermal method, the vanadium zinc sulfide is synthesized. The composite was analyzed through SEM, XRD, and XPS techniques to investigate its morphological, structural, and compositional characteristics comprehensively. The MoS2@VZnS electrode achieved a specific capacity (Qs) of 1025 Cg−1 at 3 mVs−1 after being tested in 1 M KOH. In a two-electrode set-up, activated carbon is used as a negative electrode, and MoS2@VZnS is used as a positive electrode for the fabrication of a hybrid supercapacitor. The asymmetric device has demonstrated a Qs of 285.4 Cg−1 at 1.4 Ag−1. The fabricated asymmetric supercapacitor device has manifested an excellent energy density (Ed) of 39.5 Whkg−1 and power density (Pd) of 2462.35 Wkg−1. Furthermore, in the durability test of MoS2@VZnS//AC, it exhibited an impressive capacity retention of 91.32% after enduring 5,000 cycles. Besides this, an investigation was conducted on a glucose electrochemical sensor utilizing MoS2@VZnS, to enhance its performance. The device showed extraordinary performance and considerable sensitivity against glucose, even up to a very high value. The multifunctional MoS2@VZnS nanocomposite electrode material provides new opportunities to design hybrid devices in energy storage devices and biomedical applications.

Hydrothermal synthesis of NiO nanoparticles decorated hierarchical MnO2 nanowire for supercapacitor electrode with improved electrochemical performance

In this work, MnO2/NiO nanocomposite electrode materials have been synthesized by a cost-effective hydrothermal method. The effect of the concentrations (0, 1, 3, 5, and 7 wt%) of NiO nanoparticles on the surface morphology, structural properties, and electrochemical performance of the nanocomposites was characterized by different characterization techniques. The scanning electron micrographs (SEM) reveal that the as-prepared NiO nanoparticles are well connected and stuck with the MnO2 nanowires. The transmission electron microscopy (TEM) analysis showed an increase in the interplanar spacing due to the incorporation of NiO nanoparticles. The different structural parameters of MnO2/NiO nanocomposites were also found to vary with the concentration of NiO. The MnO2/NiO nanocomposites provide an improved electrochemical performance together with a specific capacitance as high as 343 F/g at 1.25 A/g current density. The electrochemical spectroscopic analysis revealed a reduction in charge transfer resistance due to the introduction of NiO, indicating a rapid carrier transportation between the materials interface. The improved electrochemical performance of MnO2/NiO can be attributed to good interfacial interaction, a large interlayer distance, and low charge transfer resistance. The unique features of MnO2/NiO and the cost-effective hydrothermal method will open up a new route for the fabrication of a promising supercapacitor electrode.

Decorating N-doped carbon-coated cobalt phosphide nanoparticles onto N-doped carbon nanotubes for high-performance supercapacitors and efficient methanol electro-oxidation

Cobalt phosphide (CoP) has become a promising electrode material for supercapacitors and methanol electro-oxidation due to its high electrical conductivity and and multiple oxidation states. However, the insufficient electroactive sites and large volume changes restrict its electrochemical performance. Herein, a novel CoP/carbon nanocomposite electrode material is designed and synthesized by decorating N-doped carbon (NC) coated CoP nanoparticles onto N-doped carbon nanotubes (N-CNTs). N-CNTs serve as support to grow CoP nanoparticles, which effectively reduces the sizes and aggregation of CoP nanoparticles and provides more electroactive sites. Density function theory calculation results confirm that the coating of NC on CoP nanoparticles increases the electrical conductivity of CoP by transferring electrons from NC to CoP. Meanwhile, a built-in electrical field is formed at the CoP/NC interface, resulting in higher electron/ion transfer efficiency as well as easier surface OH– adsorption. Moreover, the flexible NC shell and N-CNTs supports together effectively withstand the mechanical stress and buffer volume changes of CoP during the charge/discharge processes. Therefore, the obtained N-CNTs@CoP@NC nanocomposite electrode demonstrates high specific capacities (1003 and 621C g−1 at 1 and 10 A g−1, respectively) and good cycling performance (91.2 % retention of initial capacity after 10,000 cycles at 5 A g−1). Furthermore, it also shows a current density of up to 281 mA cm−2at a scan rate of 10 mV s−1with 92.4 % retention of initial current density in 1 M KOH with 0.5 M methanol. These results highlight a feasible strategy for improving practical capacities and cyclic stability of CoP-based electrode materials by integrating nanostructured CoP with one/two-dimensional carbon materials.

Engineering 3D-interconnected graphene nanoplatelets and polyaniline nanocomposite for high energy density energy storage

A high-performance, seaweed-shaped 3D interconnected nanocomposite electrode comprising graphene nanoplatelets (GNP) and polyaniline (PANI) as an electrode material for supercapacitors is synthesized via conventional in-situ chemical oxidative polymerization. This research aims to enhance the electrochemical performance of the GNP/PANI nanocomposite electrode material by manipulating their shape and electroactive characteristics for greater optimization. While seaweed-shaped GNP/PANI nanocomposites have been reported previously, none have demonstrated high electrochemical performance with an optimized 40 wt% of GNP in GNP/PANI nanocomposite. This deficiency is attributed to the lack of 3D well-interconnected nanocomposite formation and the electroactivity of GNP/PANI when compared to individual PANI or GNP in H2SO4 electrolyte.The electrochemical study confirms an upward revision in specific capacitance, from 400 Fg−1 for GNP and 514 Fg−1 for PANI, to 1088 Fg−1 for the GNP/PANI electrode material in an aqueous 1 M H2SO4 electrolyte solution. It is envisioned that formation of such 3D interconnected GNP/PANI nanocomposite contributes in increasing the interplanar and interchain distances in the nanocomposite particularly in GNP layered structure. Additionally, it is observed that the electrochemical impedance parameters, such as charge transfer resistance Rct (0.12 Ω), high response frequency (1.367 Hz), and short relaxation time (τo ∼ 0.73 s) of the GNP/PANI nanocomposite electrode material, demonstrate excellent performance. The seaweed-shaped GNP/PANI nanocomposite exhibits promising potential as an electrode material for next-generation symmetric supercapacitors due to its high specific capacitance, low cost, and ease of fabrication.

Nanosheet@nanosheet NiZn2O4@NiZn2S4 core-shell mesoporous heterostructure as an electrode material for aqueous hybrid supercapacitors

Reasonable design of nanocomposite electrode materials with core-shell heterostructures is crucial to improve their electrochemical performance and enhance structural stability. Herein, a novel nanosheet@nanosheet NiZn2O4@NiZn2S4 (NZO@NZS) core-shell mesoporous heterostructure was synthesized on nickel foam (NF) as an electrode material for aqueous hybrid supercapacitors (HSCs). The interconnected NZS nanosheets were uniformly anchored to the vertically aligned NZO nanosheets, improving the conductivity and stability of the composite, consequently rendering the composite to exhibit excellent electrochemical performance. At a current density (Dc) of 1 A g−1, the NZO@NZS exhibits a high specific capacity (Cs) of 1516.0 C g−1. After 10,000 cycles (Dc = 15 A g−1), its capacity retention rate maintains at 86.9 %. Moreover, an HSC was assembled using the NZO@NZS as positive electrode and activated carbon as the negative electrode). At a power density (PD) of 775.0 W kg−1, the energy density (ED) is 43.4 Wh kg−1. Thus, the NZO@NZS exhibits potential as an electrode material in energy-storage devices.

Electrochemical elucidation of phosphorus-doped and 3D graphene aerogel surface-modified SiOx porous nanocomposite electrode material for high-performance lithium-ion batteries

Silicon oxide (SiOx) is promising as an earth abundant eco-friendly cost-effective anode material for lithium-ion batteries (LIBs), boasts a higher capacity compared to commercial graphite, garnering significant interest. Nevertheless, its practical application is hindered by issues related to poor cycling performance and low electronic conductivity. In this investigation, graphene aerogel-wrapped (GA) red phosphorus (P) doped SiOx (P-SiOx@GA) composite material is successfully constructed through ball-milling followed by freeze-drying and thermal treatment processes. The prepared materials are characterized the physico-chemical properties. The electrochemical performance is evaluated through Li-ion half and full (LiFePO4//P-SiOx@GA) cells configuration. The synthesized P-SiOx@GA electrode exhibits outstanding cyclic performance, demonstrating a specific capacity of 1094 mAh g−1 at 0.5C with a capacity retention of 80.3 % over 200 cycles in half-cell test. Furthermore, it demonstrates superior rate capability and delivers a reversible rate capacity of 754 mAh g−1 at 2C. Besides, the Li-ion punch cell configuration of LiFePO4//P-SiOx@GA shows good reversible capacity of 1.4 mAh at 0.5C over 300 cycles. The doping of P and porous 3D structure of GA forms an SiOx matrix network is facilitate the establishment of a 3D conductive pathway for electron transport and Li+ diffusion but also acts as a flexible matrix to accommodate the volume changes of SiOx. Therefore, the results and way of preparation promotes a practical feasibility of high-performance Si-based Li-ion batteries applications.

High-performance and stable CoSrS@rGO nanocomposite based electrode material for supercapattery device and electrochemical glucose sensor

Abstract Two-dimensional (2D) materials possess excellent electrical conductivity, notable pore size, and exceptional stability. In this research, the cobalt strontium sulfide (CoSrS) nanocomposite is synthesized using the hydrothermal process. The CoSrS@rGO nanocomposite electrode material showed much greater specific capacity of 1050 C g−1 compared to the undoped sample (300 C g−1), as determined by a three-electrode measuring setup. Moreover, the results obtained from the electrochemical impedance spectroscopy (EIS) and Brunauer–Emmett–Teller (BET) analyses indicated a noticeable enhancement in both surface area and conductivity. Further, the hybrid device (CoSrS@rGO//AC@PANI) showed power and energy densities of 39.5 Wh kg−1 and 3793 W kg−1, respectively. The hybrid device exhibited a retention rate of 70% of its initial capacity over 2000 cycles. Besides, the CoSrS@rGO nanocomposite electrode material was effectively used as an electrode for the electrochemical glucose sensor. The device showed high sensitivity and stability against the glucose. The CoSrS@rGO nanocomposite electrode exhibited a sensitivity with an R2 value of 0.99. This study offers valuable insights into the influence of temperature and conducting polymers on the performance of CoSrS@rGO nanocomposite electrode materials for multiple applications.

Effect of MoS2 and electrolyte temperature on the electrochemical performance of NiCoS@rGO-based electrode material for energy storage, oxygen reduction reaction and electrochemical glucose sensor

Two-dimensional transition metal dichalcogenides (2D-TMDs) are essential in energy storage devices. MoS2/rGO nanostructures have improved energy storage capacity because of their layered shape, proximity effect, inherent broad surface area, and edge locations. Herein, we have synthesized NiCoS@MoS2@rGO composite electrode material for supercapattery energy storage devices and electrochemical glucose sensors via the hydrothermal method. The electrochemical performance of NiCoS, NiCoS@MoS2 and NiCoS@MoS2@rGO were first investigated in three electrode assemblies at different electrolyte temperatures (27 °C to 50 °C). Among all the samples, NiCoS@MoS2@rGO shows the superior value of Qs (1138C/g or 1896.66 F/g) with 1 M KOH electrolyte solution at 50 °C. The asymmetric NiCoS@MoS2@rGO//AC device showed a high specific capacity (301C/g, at 1 A/g), energy and power densities of 65.44 (Wh/Kg), and 1267.18 (W/Kg), respectively. A significant value of Coulombic efficiency of 92.79 % and capacity retention of 83.42 % was acquired after 5000 galvanostatic charging/discharging (GCD) cycles. Further, the NiCoS@MoS2@rGO nanocomposite electrode material is used for oxygen reduction reaction activity. The initial potential for the oxygen reduction was 0.67 V vs. RHE, and the electrode showed high stability. Besides, the hybrid device is used as an electrochemical glucose sensor to detect glucose with a highly precise detection response. This research will open new ideas for developing more efficient TMDs sulfide-based nanocomposite materials for future energy storage systems and biomedical applications.

High‐Performance and Stable Polyaniline@Niobium Sulfide Electrode for an Asymmetric Supercapacitor

AbstractConducting polymers have attained a lot of interest due to extraordinary conductivity, large pore size, and surprising stability. In this work, the conducting polymer polyaniline (PANI) and niobium sulfide (NbS) were synthesized by polymerization of aniline and hydrothermal method, respectively. The PANI@NbS nanocomposite electrode material had a specific capacity (Cs) of 1050 C g−1, which is larger than that of the reference sample (NbS = 300 C g−1). Besides, the hybrid device (PANI@NbS//PANI@AC) was designed and the electrochemical characteristics were determined. The hybrid device showed an excellent value of Cs of 1207 C g−1 with higher energy density Ed and power density Pd. The device also exhibited remarkable stability, and 85 % of the initial capacity is retained after 1000 cycles.

High-performance of the ZnO/NiS nanocomposite electrode materials for supercapacitor

In this work, a single transition metal oxide (ZnO) and metal sulfide (NiS) synthesized through a hydrothermal method and their combination of composite materials have been successfully prepared a simple and an easy approch a solid-state method. As the synthesized composite (ZnO/NiS) prepared different percentage ratio such as 7:3, 5:5 and 3:7 respectively. The ZnO, NiS and their nanocomposite materials characterized by using the XRD, SEM, HR-TEM, XPS and EDAX analysis. The electrochemical performance of as prepared electrode materials analyzed by CV, GCD and EIS spectra. The synthesized nanocomposite of ZnO/NiS at 5:5 ratio exhibited the brilliant capacitance of 1322 Fg−1 at 1 Ag−1 current density, capacitance retention of 76.66 % for continuous 1000 cycles at 4 Ag−1 and also calculated the power and energy density. These results suggests the ZnO/NiS at 5:5 ratio electrode is favorable electrode for an excellent performance supercapacitor.

Enhancing the charge transfer and redox characteristics in energy storage devices with a layered ZnNbS@graphene nanocomposite electrode material for biomedical application

Hybrid supercapacitors, a type of device that integrates the functionalities of both supercapacitors and batteries, exhibit significantly enhanced power and energy densities. Two-dimensional materials particularly graphene with remarkable characteristics such as conductivity, sensitivity, and storage capacity, have garnered significant attention in the realm of energy storage. Herein, a composite electrode of zinc niobium sulfide (ZnNbS) and graphene (Gr) is designed and measured the electrochemical and biomedical applications. The composite electrode ZnNbS@Gr (75/25 ratio) showed a high value of specific capacity of 1573.01 Cg−1, much better than pristine ZnNbS (854.32Cg−1) because of the improvement in charge transfer and redox characteristics. Further, a hybrid supercapacitor device (ZnNbS@graphene//AC) is designed and achieves a specific capacity (179.2 C/g) at 1.5 A/g. The energy density is establish 42.1 WhKg−1, whereas the power density is 2500 WKg−1. This device is measured up to 5000 charging and discharging cycles, obtained a high value of capacity recantation of 96 %. Besides, this device is used to accurately detect the glucose to a small amount of 0.01 mM. The conclusions of our investigation provide a remarkable beginning for the advancement of high-capacity energy storage systems and biomedical applications.

Facile synthesis of dysprosium oxide/bismuth oxide nanocomposite electrode materials with good electrocatalytic performance

Background: Benzoic acid is widely applied in the food field, including beverages as the antimicrobial preservative due to its strong inhabitation role to bacteria and yeasts. However, excessive intake of benzoic acid can easily cause abdominal pain and diarrhea and can even result in metabolic diseases. Hence, it is important to seek simple, accurate and sensitive strategies to detect low-trace benzoic acid. Objective: The aim of this study is to synthesize dysprosium oxide/bismuth oxide nanocomposites using dysprosium sulphate and sodium bismuthate as the raw materials and research the electrochemical sensing properties for the detection of benzoic acid. Methods: Dysprosium oxide/bismuth oxide nanocomposites were synthesized by a facile hydrothermal route. The dysprosium oxide/bismuth oxide nanocomposites were characterized by X-ray diffraction, electron microscopy, X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy. Results: The dysprosium oxide/bismuth oxide nanocomposites are composed of nearly circular-shaped particles with polycrystalline cubic Dy2O3 and triclinic Bi2O3 phases. The size of the nearly circular-shaped particles is about 50 to 200 nm. The electrons are easier to transfer by the dysprosium oxide/bismuth oxide nanocomposite-modified electrode than the bare electrode. A pair of quasi-reversible cyclic voltammetry (CV) peaks located at -0.155 V and -0.582 V exist in the CV curve of 0.1 M KCl buffer solution containing 2 mM benzoic acid. The nanocomposite-modified electrode shows a linear detection range and detection limit of 0.001-2 mM and 0.18 μM, respectively, for benzoic acid detection. Conclusion: The dysprosium oxide/bismuth oxide nanocomposite-modified electrode reveals superior electro-catalytic activity towards benzoic acid.

Exploration of La2O3-CuO nanocomposite as an effective electrode material for asymmetric supercapacitor applications

Supercapacitors (SCs) were recently developed as an inexpensive and high-efficiency energy storage technology. A synergistic effect on binary metal oxide composites has been regarded as the desired strategy for enhancing energy storage. In this research work, a binary metal oxide La2O3-CuO nanocomposite was prepared by an ultrasonic-assisted hydrothermal approach. The electrochemical performance is estimated using techniques such as cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electro-impedance spectroscopy (EIS). The La2O3-CuO nanocomposites attained a maximum specific capacity of 930 mAh g−1 at current density of 0.5 A/g and a better cycling stability of 85.25 % even after 2000 continuous charge-discharge cycle. The electro impedance spectroscopy EIS revealed the La2O3-CuO nanocomposites have lower solution resistance (Rs), charge transfer resistances (Rct) of Rs 0.469 Ω and Rct 0.414 Ω, respectively. Moreover, the synthesised La2O3-CuO electrode material attained energy density 13.02 Wh/kg and excellent power density 1205 W/kg along with significant capacitive retention 88.63 % even after 10,000 cycles.The outstanding electrochemical performance makes the binary nanocomposite La2O3-CuO promising electrode material for electrochemical energy storage supercapacitors.

Silicon intercalation on MXene nanosheets towards new insights into a superior electrode material for high-performance Zn-ion supercapacitor

MXenes seem promising as a new two-dimensional (2D) material for energy storage and conversion applications due to their excellent conductivity, efficient accordion-like layered structure, surface chemistry, and many organized nanochannels. Nevertheless, the demonstration of MXenes' superiority is impeded by an accumulation of interlayers and the chemical sluggishness of structural components. With silicon (Si) pre intercalation techniques on V2CTx, MXene is able to increase its interlayer spacing and excite the outermost vanadium atoms, resulting in a frequent transfer and high storage capability of Zn-ions in supercapacitors (SCs). Motivated by the distinctive properties of Si and MXene, we have reported the V2CTx@Si nanocomposite electrode material for SC in this work. Si nanospheres act as spacers to intercalate into the MXene interlayers, increasing the ion transport channels while simultaneously lowering the ion transport resistance. The V2CTx@Si nanocomposite electrode delivers a maximum specific capacitance of 557.7 F/g at 1 A/g. The outstanding performance of the V2CTx@Si electrode material is demonstrated by DFT simulations, thanks to its electronic characteristics. These findings indicate that the V2CTx@Si possesses enhanced conductivities than the pristine MXene, which is beneficial for the rate performance of V2CTx@Si. The obtained Eads value of the V2CTx@Si is −0.845 eV, higher than the pristine material (−0.652 eV), indicating energetically favorable. A zinc–ion supercapacitor (ZISC) is constructed via coupling V2CTx@Si as a cathode and Zn foil as an anode (denoted as V2CTx@Si//Zn). The V2CTx@Si//Zn can function at a wide potential range of 1.8 V and provide a high capacitance of 318.25 F/g at 1 A/g with a consistent cyclic life (96.4 %) up to 10,000 cycles. Furthermore, the V2CTx@Si//Zn possessed a maximum energy density of 143.33 Wh/kg at a power density of 900.72 W/kg, outperforming previously reported similar work.

Preparation of photoluminescent nanocomposite by one-step method from cobalt oxide-Jeffamine based on novel polymer dot as a high-performance and ultra-stable symmetric supercapacitor

Polymer dots are a new class of quantum dots that have attracted much attention from researchers. Based on, in this work, for the first time, using a one-step method, the new PDJA-Co3O4 nanocomposite with a quantum yield of 65.45%, based on the polymer dot of jeffamine was synthesized, which has ideal supercapacitor properties. The new polymer dot-based Jeffamine (PDJA) was first synthesized using a Jeffamine polymer and simultaneously composited with cobalt oxide by the solvothermal method. The photoluminescence properties and supercapacitor performance of the PDJA-Co3O4 nanocomposite and the PDJA were investigated. The PDJA-Co3O4 nanocomposite and the PDJA were prepared as electrode materials, and analysis of CV, GCD, and EIS was performed that the specific capacitance of the PDJA-Co3O4 nanocomposite electrode material and the PDJA electrode material are 978 F.g−1 and 283 F.g−1 at 50 mV/s, respectively. Also, the PDJA-Co3O4 nanocomposite and the PDJA have cyclic stability of 98.37% and 91.57% up to 10,000 cycles of cyclic voltammetry at 100 mV/s, respectively. Then, two symmetric supercapacitors were manufactured of the PDJA-Co3O4 nanocomposite and the PDJA. Finally, due to the high conductivity of the PDJA-Co3O4 nanocomposite active material, the symmetric supercapacitor of PDJA-Co3O4 nanocomposite turned on the LED lamp.