Electrode Materials Research Articles

Ternary metal oxide carbon composite as high-performance electrode material for supercapacitor applications

Recently, ternary metal oxides carbon composites recognized as metal organic frameworks (MOFs) have gained striking attention for supercapacitor electrode material due to high surface area, porosity, chemical stability, tunable properties, redox activity, and eco-friendly material. ZIF-67 is a novel MOF possessing these characteristics. Therefore, the present work reports the development of ternary iron-nickel–cobalt ZIF-67 composites (FeNiCo ZIF-67) using co-precipitation method with the variation in molar concentration of iron oxide, nickel oxide, and cobalt oxide. Physico-chemical characterizations of developed materials were investigated through X-ray diffraction (XRD), Raman spectroscopy, energy dispersive X-ray (EDX), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) to confirm the successful formation of composites and structure, morphology. Then, the electrodes were fabricated for all three synthesized composites and electrochemical analyses such as cyclic voltammetry (CV), galvanic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS) were performed. The results revealed the porous polyhedral structure of FeNiCo ZIF-67 with different compositions consisting of interconnected nanoparticles played an important role in increasing the charge storage capacity of the material. Among the composites, FeNiCo ZIF-67 (1:2:1) electrode material achieved the highest specific capacitance of 532.7 F/g at a current density of 1 A/g. FeNiCo ZIF-67 (1:2:1) exhibited maximum electrochemical active surface area 89.12. Electrochemical impedance spectroscopy (EIS) demonstrated the minimal resistance of 7.8 Ω by FeNiCo ZIF-67 (1:2:1) composite electrode compared to the other two electrode materials. Cyclic stability study revealed the capacitance retention of 91 % after 10,000 continuous charge discharge cycles at a current density of 10 A/g. Electrode material demonstrated an outstanding electrochemical performance, and this work could provide a simple strategy to fabricate FeNiCo ZIF-67 nanostructured electrode materials for supercapacitors.

Ni-In-oxalate nanostructure as electrode materials for high-performance supercapacitors

Energy storage technologies play a crucial role in addressing the intermittent characteristics of renewable energy sources, improving the stability of electrical grids, and decreasing the release of greenhouse gas emissions. In this study, we presented nickel indium oxalate (Ni1-xInxC2O4) as a promising material with potential applications in the field of electrochemical energy storage. The as-prepared Ni-In- oxalate sample was subjected to different physical characterizations, including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Regarding the electrochemical energy storage capability, the Ni1-xInxC2O4 electrode material exhibited a specific capacitance of 835 F g-1 (417.5 C g-1) at 1 A g-1. The incorporation of nickel into the indium oxalate nanoplates enhances their electrochemical performance. The presence of nickel in the nanoplates generated from substrate, improving the overall conductivity of the material and enhances its electrochemical reactions, thus leading to improved energy storage capabilities.

Efficient hybrid supercapacitor performance enabled by large surface area of 2D mesoporous zinc sulfide nano-sheets synthesized via microwaves

Researchers have shown a significant amount of interest in synthesizing high energy density supercapacitors using a simplest, fast, and low cost technique. The electrochemical performance of supercapacitors can be impacted by the surface area and morphology of electrode materials. A one-step, rapid, and economical microwave-assisted synthesis technique was employed in this study in order to prepare mesoporous nanosheets that are composed of zinc sulfide. The ZnS-based nanosheets possess a large surface area of ∼120 m2g−1 and a mesoporous structure of a pore diameter of <22 nm, which offers numerous electrochemical active sites and it facilitates an excellent super capacitive performance, which is due to its shortened ion/electron diffusion path. The prepared mesoporous nanosheets exhibit a higher specific capacitance of 2282 Fg−1 (1037 C/g) when subjected to a 1 Ag−1 in 2 M KOH aqueous electrolyte with high capability rate. The fabricated device exhibits a high specific capacitance of 252.5 Fg−1 (140 C/g) at 1 Ag−1, which produces a remarkable energy density of about 90 Whkg−1 at 800 Wkg−1 value of power density and an excellent retention of ∼95 % after 10,000 cycles at 6 Ag−1. This study designed an instant, straightforward and low-cost approach to fabricate ZnS nanosheet electrode materials that exhibit excellent performance for supercapacitor applications.

MnOOH nanorods decorated with CeO2 nanoparticles as advanced electrode for high-performance supercapacitor

The development of novel composite electrode materials is essential to fabricating supercapacitors with high specific capacitance and good stability. In this study, MnOOH nanorods adorned with CeO2 (CeMn composites) have been satisfactorily synthesized through in-situ growth of tiny CeO2 nanoparticles using hydrothermal treatment. SEM images revealed that the granular CeO2 particles are adhered to the surfaces of nanorod-shaped MnOOH. XRD analysis confirmed the CeMn composites maintain the crystal structure of MnOOH and CeO2 with high purity. The EDS elemental mapping images demonstrated that Mn, O, and Ce elements are homogenously dispersion distributed in the CeMn composites. The supercapacitive performance of the MnOOH and CeMn composites pasted onto the Ni foam was evaluated determined through electrochemical measurements. The Ce0.05Mn1 (Ce/Mn molar ratio of 0.05/1) as a supercapacitor electrode exhibited an excellent specific capacitance of 857.62 F/g at 1 A/g, which is higher than the values for the MnOOH. Moreover, the prepared Ce0.05Mn1 still could retain good cycling stability over 3000 charge/discharge cycles. This study presents a feasible route to develop high-performing supercapacitor electrode materials.

Ultrasonic Synthesis of MOF-based Hybrid Composite for Electrochemical Detection of Furazolidone Antibiotic in Food and Biological Samples

This study reveals the development of a new combination of Bi-MOF/ functionalized carbon nanofiber (f-CNF) composite modified electrode for the electrochemical sensing of Furazolidone (FUZ) antibiotics. FUZ is used to prevent bacterial infections in animals, and an overdose of FUZ leads to several health issues. Bi-MOF/f-CNF provide excellent surface area, high conductivity, and electrocatalytic activity for the effective detection of FUZ. Various characterization techniques were used to analyze the structural, morphological and compositional properties of Bi-MOF/f-CNF. The fabricated composite was coated onto a glassy carbon electrode (GCE) and rotating disk glassy carbon electrode (RDGCE) to study its electrocatalytic behavior using different voltammetry techniques. Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) analysis of the electrode material confirmed its high electroactive surface area, low charge transfer resistance, and excellent charge transfer ability. The electrochemical quantification of FUZ was performed using differential pulse voltammetry (DPV) and amperometric (i-t) techniques. The linear range, limit of detection (LOD) and sensitivity are 0.199 to 238 μM, 20.8 nM and 43.99 μA μM−1 cm−2, respectively, as determined by the DPV technique. Additionally, the LOD, linear range and sensitivity were obtained as 3.64 nM, 0.002 to 700 μM and 0.827 μA μM−1 cm−2, respectively using i-t quantification technique. The invented electrode material exhibits better stability in the presence of other interference molecules and it shows good repeatability and reproducibility for the detection of FUZ. Due to the excellent analytical properties, the Bi-MOF/f-CNF modified electrode could be the potential contender for the electrochemical detection of FUZ in the real samples.

Recent advances in heteroatom doped transition metal sulfides for high-performance supercapacitors

Supercapacitors have been well focused on, due to the advantages of fast charging/discharging, high power density, long service time and safety. Electrode materials determine the performance of supercapacitors. Serving as a kind of battery-type materials, transition metal sulfides have been received more attentions for high redox activity and high specific capacity. Controllable synthesis of metal sulfides determines their microstructure and composition, which is the basis for developing new materials. Therefore, this review firstly introduces existing synthetic methods of transition metal sulfides, including hydrothermal/solvothermal method, template method, electrodeposition method, sol-gel method, co-precipitation method, exfoliation/intercalation method and solid state method. The preparation process, principle, advantages/shortages of each method and related examples are highlighted. Taking controllable synthesis as the main line, recent advances of heteroatom doped metal sulfides and their application in supercapacitors are introduced in the second section. According to the type of dopants, all doped metal sulfides are divided into two parts: nonmetal doped metal sulfides, including B, N, F, O, P and Se, and metal doped sulfides, including alkali metal, precious metal, rare earth metal and transition metal. The research progresses about materials preparation, structure feature and supercapacitance performance are summarized. At last, current issues and future prospects in the field of heteroatom doped metal sulfides are proposed. It is anticipated that the review will provide guiding ideas or strategies for developing high-performance metal sulfides electrode materials.

Development of Binder–free Ni3S2/CoS2 nano–composite as electrode material for Energy Storage Application

Global energy crisis imposes immense obstacles leading towards development of innovative devices, and supercapacitors (SCs) are thought to be a viable energy storage technology. The engineering of nanostructured materials with a distinct and consistent morphological design is seen as a better option for various range of electrochemical energy sources. This study reports novel binder-free Ni3S2/CoS2 electrode material that acquires higher energy, higher energy density, as well as its simple preparation method, low cost, and earth–abundant resources. The morphological, structural, and textural characteristics resulted in surface area of 46 m2 g–1 of Ni3S2/CoS2 that will increase active sites also. The synthesized nanocomposite has particle size of 41.1 nm that leads to enhanced active sites and greater surface area as confirmed through BET analysis. Ni3S2/CoS2 nanocomposite has high specific capacity around 828.14 F g–1 at 5 mV s–1 sweep rate using 2 M KOH, a high energy density around 115.01 Wh kg–1, and power density of 1000 Wh kg–1. Ni3S2/CoS2 acquires higher ionic conductivity of 5 S m-1, this will enhance the inter-layer transference of electrons, and these results perfectly correlates with EIS, resulting in charge transfer resistance value of 0.9 Ω for nano-composite. These enhanced electrochemical capabilities of Ni3S2/CoS2 hold significant potential in practical viability.

Waste wood tar based porous carbon electrodes for supercapacitors with excellent performances through condensation cross-linking modification

Wood tar is an unavoidable by-product during a slow-pyrolysis process of biomass, which is usually discarded as a waste and results in environment pollution. Recently, wood tar has been used as a starting material for carbon electrodes because of its thermoplasticity and high carbon content. However, wood tar is mainly composed of various light phenolic molecules, which usually leads to a low carbonization yield after carbonization and an inferior electrochemical performance after activation. In this work, in order to improve the carbonization rate and electrochemical performance of these materials, wood tar was first condensed and crosslinked with formaldehyde and urea via a condensation reaction to produce condensed macromolecular resins, which were then carbonized at 550°C and activated with KOH at 800°C to prepare high-performance nitrogen-doped carbon electrodes for supercapacitors. The samples possess high carbonization yield, large specific surface area (3515.1 m2g-1) and moderate nitrogen content (1.11%). The high-performance carbon electrodes fabricated by this method achieves a high capacitance of 437.8Fg-1 (6M KOH electrolyte) at 1A/g-1. The assembled supercapacitor has an energy density of 13.41Whkg-1 at a power density of 124.93Wkg-1. And the capacitance retention was essentially 100% after 10000 cycles at 5Ag-1. The study presents an innovative strategy for the production of porous carbon for supercapacitors using wood tar and improves carbonization yield via condensation cross-linking modification.

Asymmetric supercapacitors assembled by hollow N, s co-doped carbon spheres decorated FeOOH and Co3S4 nanoparticles

Exploiting advanced anode and cathode materials with distinctive architectures and multi-component participation is of great significance to boosting the energy density of asymmetric supercapacitors. Herein, ultra-fine FeOOH nanoparticles are in situ grown on the hollow N, S co-doped carbon (HNSC) spheres using a facile solvothermal strategy and subsequent calcination process. Benefiting from the attractive hollow architecture and the synergistic effect between FeOOH and HNSC, the FeOOH/HNSC composite as anode for supercapacitors delivers an optimal capacity of 588.2C g−1 (1 A g−1) and remains 88.3 % of its initial value after 10,000 cycles at 15 A g−1 in 6 M KOH. Furthermore, the HNSC-supported Co3S4 nanoparticles are also prepared through a one-step solvothermal strategy. The obtained Co3S4/HNSC composite as cathode achieves a capacity of 420C g−1 (1 A g−1) and maintains a high retention of 95.3 % after 10,000 cycles at 15 A g−1. The constructed asymmetric supercapacitor using FeOOH/HNSC and Co3S4/HNSC as anode and cathode appears to possess a superior energy density of 82.3 Wh kg−1 at 821.6 W kg−1 with retention of 84.9 % after 10,000 cycles at 10 A g−1. These attainments demonstrate that constructing multi-component electrode materials with unique structures is an effective method to optimize the electrochemical characteristics of asymmetric supercapacitors.

Cu@MOF based composite materials: High performance anode electrodes for lithium-ion and sodium-ion batteries

In order to satisfy the increasing demand for energy, it is essential to improve the efficiency of lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) batteries. Metal selenides (MSes) have a high theoretical specific capacity, can be designed in a variety of ways, conduct electricity well, can change morphology easily, and have a multi-electron reaction mechanism. These characteristics make them very competitive as anode materials for LIBs and SIBs. Herein, we synthesise Cu@MOF and Cu@NH2-MOF as the precursor to prepare Cu1.95Se embedded into porous carbon matrix (Cu1.95Se@PC) and porous-N-doped carbon matrix (Cu1.95Se@NPC) via pyrolysis process of Cu@MOF and Cu@NH2-MOF, respectively. Cu1.95Se@PC and Cu1.95Se@NPC electrodes for half-cell LIBs and SIBs exhibit a high reversible capacity of 313.1, 480.9 (for LIBs), 216.3 and 303.8 (for SIBs) mAhg−1after 1000 cycles at 2 A g−1, respectively. We assess the electrochemical performance of the Cu1.95Se@PC and Cu1.95Se@NPC anodes by integrating them with commercially available LiFePO4 (LFP) into full-cell LIBs. The LFP//Cu1.95Se@PC and LFP//Cu1.95Se@NPC full-cells have discharge capacities of approximately 330 and 293 mAh g−1 at 0.3 A g−1 at the initial cycle. In order to explore the sodium storage mechanism of the Cu1.95Se composites, we conducted an in situ XRD test during the first charge/discharge cycle, considering their favourable cycling and rate performance. Our work provides a promising anode electrode material for both half-cell LIBs and SIBs with high volume utilization and superior electrochemical performances.

The effect of oxygen vacancy in SnO2 based anodes on ozone generation and tetracycline removal

The electrochemical ozone production (EOP) during water oxidation represents a valuable method for producing pure ozone, which has attracted great attention. Oxygen vacancies on the surface of electrode materials can improve the electrocatalyst activity, but the mechanism remains unclear. Herein, the Ni-Sb-SnO2 (NSS) electrodes with different oxygen vacancies concentration were obtained by electrochemical activation, aiming to improve the ozone generation performance and the removal rate of pollutant. Moderate oxygen vacancies were conductive to generate a large number of new active sites or reactive surface oxygen species (O2-x) for promoting the oxygen molecules and oxygen intermediates to form ozone. The 1.1 %-Al-Ce-NSS electrocatalyst exhibited excellent EOP performance with a Faraday efficiency (FE) of 36.76 % at the current density of 40 mA·cm−2 and it achieved an optimal potential of 2.63 V (vs RHE) at 10 mA·cm−2, which was almost 1.5 times as much as that of 4.5 %-Al-Ce-NSS electrode. In addition, about 90.56 % of 10 mg·L−1 tetracycline (TC) could be removed through the 1.1 %-Al-Ce-NSS electrocatalyst in 40 min, and the ·OH was proved to be the main active species.

Polyaniline@MoS2: An organic and inorganic hybrid framework for asymmetric supercapacitor applications

The polyaniline and MoS2-based organic and inorganic hybrid composite have been synthesized by varying MoS2 concentrations ranging from 1 to 10 wt% and their charge storage performances were analyzed in a three-electrode and in asymmetric cell configuration to understand their electrochemical characteristics. The electrochemical characteristics of the as-prepared electrodes such as cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy were studied in 1 M H2SO4 electrolyte. Among the prepared compositions PANI@MoS2 (5 wt%) electrode showed a high specific capacity of 148.6 F g−1 at 0.5 A g−1 among the prepared compositions. Further, the asymmetric hybrid pouch cell was fabricated where PANI@MoS2 and activated carbon were used as a positive and negative electrode, respectively. The 2 × 2 cm2 asymmetric cell (AC||PANI@MoS2(5 wt%) delivered a specific energy of 32 Wh kg−1 at a specific power of 3.2 kW kg−1 in the PVA-H2SO4 hydrogel electrolyte. This specific energy is two-fold higher than the AC||PANI asymmetric cell where the specific energy and specific power are about 18.66 Wh kg−1 and 3.2 kW kg−1, respectively. The cycle stability of the AC||PANI@MoS2 (5 wt%) was also performed at 2 A g−1 and the cell showed capacitance retention of about 99.27% after 13,000 cycles. The cell performances at different bending angles were analyzed to ensure the flexible nature of the pouch cell. Thus, the proposed organic and inorganic hybrid composite electrode is believed to be a potential electrode material for supercapacitor application in an acidic electrolyte medium.

Preparation of lignite-based porous carbon for high performance supercapacitor and the correlation between pore structures and electrochemical performance

Porous carbon exhibits considerable potential in energy storage field due to its remarkable electrical conductivity and adjustable pore structure. Nevertheless, the electrochemical performance of the material will be significantly impacted by its unreasonable pore structure. In this study, lignite was used as raw material to prepare lignite-based porous carbon by one-step activation method and the pore structure was optimized to improve its electrochemical performance and expand the utilization of low-rank coal. The results reveal that the porous carbon prepared at 600 °C has a higher specific surface area (940 m2 g−1) and a suitable pore structure (71 % mesopore), which enable adequate charge storage and fast transport of electrolyte ions, resulting in excellent electrochemical performance. In the three-electrode system, the lignite-based porous carbon exhibits a notable specific capacity of 331 F g−1 at the current density of 0.5 A g−1 and retains 96.4 % initial capacitance after undergoing 10,000 cycles. When assembled into a symmetrical supercapacitor, the device provides an energy density of 6.5 Wh kg−1 at a power density of 250 W kg−1. Even after 10,000 cycles, the capacitance retention rate is kept at 91 %, and the coulombic efficiency remains close to 100 %. These findings demonstrate that cost-effective porous carbon can be prepared by a simple route using lignite, hence exhibiting promise as electrode materials for high-performance supercapacitors.

Efficient Synthesis and Electrochemical Profiling of Nickel Tungstate for Supercapacitor Application

The Nickel Tungstate nanomaterial was synthesized by the green synthesis method. The powder x-ray diffraction analysis was carried out for Nickel Tungstate and its crystalline nature was identified. The optical properties of the Nickel Tungstate were studied. The surface morphology of the Nickel Tungstate was tested using a scanning electron microscope (SEM). The surface area analysis was obtained by BET analysis. X-ray photoelectron Spectroscopy was used to identify the Binding energy of the materials. The electrochemical properties were investigated using Cyclic Voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS), and Charge-Discharge (GCD). The highest cyclic stability for 10000 charge and discharge cycle was reported in this paper with good retention at 98%. NiWO4 NPs electrode material shows high specific capacitance values of 425 F/g−1, 300 F/g−1 and 605 F/g−1 at a scan rate of 3 mA/g for pH5, pH6 and pH7 respectively.

CNT Functionalized GdCoBi Ternary Metal Oxide Nanocomposite for Electrochemical Detection of Perfluorooctanoic Acid and Energy Storage Applications

Perfluorooctanoic acid “Forever Chemical” presents substantial ecological challenges owing to its persistence and resistance to degradation. The study introduces a novel approach by integrating ternary metal oxides—Gd2O3, Co3O4, and Bi2O3 with carbon nanotubes to develop a versatile electrode material, CNT@GdCoBi NCs, which demonstrates dual functionality as both an electrochemical sensor for PFOA and a component for energy storage devices. The electrode exhibits outstanding electrochemical sensing performance, with a detection limit for PFOA of 4.9 ppb. Interference tests reveal the electrode's high selectivity for PFOA, with a tolerance limit of ≤5%. Practical application on various fruits, vegetables, and water samples shows an average relative standard deviation (%RSD) between 4.8 and 5.6%, underscoring the practical effectiveness of the CNT@GdCoBi NCs electrode. Furthermore, the CNT@GdCoBi NCs exhibit remarkable supercapacitor performance, achieving a specific capacitance of 1197F/g at 2A/g, which is 1.5 times higher than that of GdCoBi NCs. At a current density of 2A/g, the symmetric supercapacitor device demonstrates a specific capacitance of 269F/g, along with a high energy density of 52Wh/kg at a power density of 500W/kg. Additionally, the CNT@GdCoBi NCs electrode maintains good durability, retaining 94% of its capacitance after 10,000 cycles.

Removal of Cr(VI) from electroplating wastewater by CoNi-LDH@NHCS electrode and its electrocatalytic ammonia production

Excess Cr(VI) and nitrates from industrial processes can pose a serious threat to humans and the environment. In this study, a CoNi-layered double hydroxide@nitrogen doped hollow carbon sphere (CoNi-LDH@NHCS) electrode was prepared and used for Cr(VI) removal by capacitive deionization (CDI) as well as waste CoNi-LDH@NHCS electrodes were used for ammonia production (NO3RR). The CoNi-LDH@NHCS electrode could remove up to 98.66 % of 10 ppm Cr(VI). In the actual electroplating wastewater, the removal of Cr(VI) by CoNi-LDH@NHCS electrode was 73.91 %, which showed good deionization performance. Density-functional theory calculations show that the oxygen atoms in the Cr(VI) anion and the hydrogen atoms on the surface of the electrode form hydrogen bonds and are adsorbed on the surface of the electrode under the effect of polarity, and the OH bonds on the surface of the electrode are elongated or even dehydrogenated and eventually form Cr(III)-OH. We also produced a high ammonia yield of 30.51 mg h−1mgcat−1 by using the CoNi-LDH@NHCS electrode that was discarded after the adsorption cycle as a catalyst for electrocatalytic nitrate reduction. This work enabled the sustainable use of electrode materials in addition to offering an effective technique for removing Cr(VI) from electroplating wastewater.

Trends and insights into alloying elements impact on predicted battery voltage in metal-ion batteries

In recent years, metal-ion batteries have been the focus of extensive research. A significant challenge in utilizing certain ions, particularly multivalent ions, has been identifying suitable electrode materials. To address this, we developed a machine-learning model using LightGBM to predict the average voltage of metal-ion batteries based on electrode composition in the charged and discharged states. Our model achieved a prediction error of 0.26 V when benchmarked against several experimentally obtained values. Moreover, we provide key trends as to how the addition of alloying elements such as Manganese, Iron, Cobalt, Nickel, and Aluminium in the electrode affects the output voltage. Furthermore, by screening several thousands of novel electrode compositions obtained by alloying these elements, we provide a set of 12 compositions that are predicted to have an average voltage >4.5 V.

Effect of argon and nitrogen environments on the structure and properties of protective cermet coatings based on titanium borides obtained by electric arc surfacing

The aim of this work was to enhance the mechanical and tribological properties of an alpha titanium substrate by forming a protective cermet coating on its surface. In this study, protective cermet coatings based on titanium borides were prepared by electric arc surfacing in a protective environment. Two types of protective environment were investigated during the surfacing process: (i) inert (argon) and (ii) reactive (nitrogen). The characteristic zones of the deposited layer were established depending on the environment used, and the coating-substrate transition zone was thoroughly examined. It was demonstrated that the formation of the transition zone results from the mutual diffusion of the molten material of the electrode material and the substrate. For the first time, the formation of TiB2-TiN eutectic in the form of whiskers 4-20 μm wide and 100-300 μm long distributed in the matrix of the Ti(B,N)x solid solution was established when forming a protective cermet coating in a nitrogen environment. The presence of this TiB2-TiN eutectic led to a significant increase in the hardness of the coating, up to 4.4 times, from 350 to 1530 HV. Tribological tests of surfacing coatings were conducted, and both 2D and 3D profiles of the wear grooves are presented, providing insight into the wear mechanism. It was found that the wear resistance of the cermet coating obtained in a nitrogen environment increased by 5.2 times, while in an argon environment it increased by 3.1 times as compared to the substrate without the protective cermet coating. The results indicate the potential of the developed protective cermet coatings for use in abrasive operating conditions.

Nickel foam supported CuO/Co3O4/r-GO is used as electrode material for non-enzymatic glucose sensors and high performance supercapacitors

Nickel foam supported CuO/Co3O4/r-GO is used as electrode material for non-enzymatic glucose sensors and high performance supercapacitors

Facile synthesis of Co/Fe bimetallic doped Ni3S2 nanosheets and supercapacitor performance

Ni3S2 is an outstanding electrode material due to its high theoretical specific capacity, however, in practical research, the higher theoretical capacity is difficult to show, and the change of the structure in the cycling process affects the cycling stability, which limits its practical application. To address these issues, this study presents a strategy to synthesize Fe and Co bimetallic doped Ni3S2 nanosheets on nickel foam (NF) surface. This strategy introduces bimetallic atoms quickly and easily while synthesizing nanosheet structures, and the resulting synergistic interactions between the bimetals and the mutual support effect of the nanosheets can effectively enhance electron transfer and improve cycling stability. The electrochemical results show that the Fe and Co-doped sample (Ni3S2-Co/Fe-5) exhibits a specific capacitance of 3351 F·g−1 at 1 A·g−1 in the three-electrode system, which is nearly five times higher than the specific capacity of the undoped Fe and Co-doped sample (Ni3S2), and the capacity retention rate after cycling 5000 cycles at a current density of 10 A·g−1 is 100 %, the prepared sample (Ni3S2-Co/Fe-5) was assembled with activated carbon (AC) to form a hybrid supercapacitor, which could provide a maximum power density of 9818 W·kg−1, a maximum energy density of 66.25 Wh·kg−1, and a capacity retention of 94.5 % after 10,000 cycles, with a capacity loss of only 5.6 %.