Sequential Electrodeposition Research Articles

A Single Chamber Urea/Persulfate Fuel Cell: Optimization of Cathode to Use Peroxydisulfate Electron Acceptor

Environmental and energy issues draw considerable attentions in the modern society. One of the options to simultaneously solve these issues can be a wastewater fuel cell to recover energy during wastewater treatment. The urea oxidation reaction (UOR) has been tackled to enhance the energy efficiency of electrochemical hydrogen production and/or fuel cell utilizing urea, an abundant nitrogenous pollutant in human (livestock) wastes, as an electron donor. In spite of the significant progresses on a direct urea fuel cell (DUFC), various problems were reported for real wastewater, in relation to the membrane fouling to hamper practical applications from urine. To this end, this study proposes a single chamber DUFC employing Ni-Cl as an anode, CuO/CN as a cathode, and peroxydisulfate (PDS) as an electron accepter. An ideal utilization of PDS should increase the open circuit voltage than O2, while catalytically activated PDS can eliminate aqueous pollutants (including urea) for urine treatment. The Ni-Cl anode was prepared by a simple HCl etching of Ni foam, enhancing the UOR activity compared to the mother foam. The CuO/CN cathode was prepared by a sequential electrodeposition and hydrothermal treatment. This presentation focuses on an enhanced catalytic activity of direct/indirect PDS reduction on the Ni-Cl and CuO/CN, as confirmed by cyclic voltammetry and constant load discharge of a single chamber urea/PDS fuel cell. In particular, this study interrogated the mechanism of urea oxidation in the single-chamber DUFC in comparison with a chemical PDS activation system. A proto-type single chamber fuel cell marked a maximum power density of 1.8 mW cm-2 with 0.3 M urea, to open a new era of urine fuel cell without usage of membrane and precious element catalysts.

Electrochemical synthesis of bimetallic Cu-Cd nanoparticles via sequential electrodeposition and co-electrodeposition and involved alloy formation

Electrochemical synthesis of bimetallic Cu-Cd nanoparticles via sequential electrodeposition and co-electrodeposition and involved alloy formation

In-situ realtime study of zinc selenide nanoparticles sustained by polypyrrole in alkaline water oxidation

Interest in metal electrodeposition for synthesizing customized nanomaterials has resurged, particularly for applications such as sensors and fuel cells. The present study involved the synthesis of ZnSe nanoparticles (via hydrothermal method) while polypyrrole and novel composite Ppy@ZnSePpy@Ppy (via sequential electrodeposition technique) on a glassy carbon (GC) electrode and their physiochemical, electrochemical, and operando spectro-electrochemical characterizations towards oxygen evolution reaction (OER). Results indicated that ZnSe nanoparticles are well embedded within the Ppy layers and during OER the composite electrocatalyst approached 398 mV at 10 mA cm−2 and exhibited Tafel value (b ∼ 75 mV dec−1) with ECSA (0.03) which shows better results than other two. In addition, the operando spectro-electrochemical spectra of the composite revealed the significant generation of active intermediate oxygen species of selenium and Zn2+. The important feature of the current work is the disclosure of Se's questionable role and species involved in OER found to be Se4+.

Enzymatic phenolics removal by tyrosinase-modified micromotors

In this study, self-propelled Pt/PPy-COOH micromotors were produced by using the sequential electrodeposition of Pt and PPy segments. Fabricated micromotors were modified with tyrosinase enzyme and was used to investigate the phenolic compound removal capacity. The micromotors was characterized by SEM and EDX analyses, and it was found that the shape of the motors was tubular and 10 µm long. The optimum pH values of free and immobilized enzymes were found to be 7.5, while the optimum temperature values were 45 °C. In the thermal stability study, it was determined that the immobilized enzyme showed 75 % activity after 5 h, while the activity of the free enzyme was around 21 %. Also, immobilized tyrosinase showed 55 % activity after 10 repeated uses. Finally, the phenol, p-cresol and o-phenylenediamine removal efficiencies of tyrosinase-based micromotors were found to be 54.54 %, 46.96 % and 53.87 % in 5 min, respectively. As a result, it can be concluded that it is possible to use tyrosinase-based micromotors as an alternative to traditional methods for phenol removal.

Fabrication of ultrafine PtPd alloy/ionic liquid-carbon dots nanocomposites modified flexible carbon fiber as enzyme-free amperometric sensing for H2O2 in living cells

Given the pivotal role of hydrogen peroxide (H2O2) in numerous biological progresses, there has been a recent surge in the development of highly effective electrochemical sensors for H2O2 detection. In this article, we propose an enzyme-free amperometric system for the sensitive and selective recognition of H2O2, leveraging ultrafine PtPd alloy/ionic liquid-carbon dots (IL-CDs) nanocomposites modified flexible carbon fiber. The IL-CDs were synthesized through the direct electrodeposition of ionic liquid [BMIM][PF6] using Pt sheets as electrodes. Subsequently, a sequential electrodeposition of IL-CDs, H2PtCl6, and PdCl2 onto the activated carbon fiber (ACF) yielded the PtPd/IL-CDs/ACF microelectrode. This microelectrode serves as an enzyme-free amperometric sensor for H2O2 detection, exhibiting an improved response with a significantly lower detection limit of 0.29 μM and a relatively broad linear range spanning from 2 to 6561 μM. Furthermore, this enzyme-free amperometric H2O2 sensor demonstrates remarkable stability over extended periods and exceptional performance in practical applications, such as the analysis of commercially available milk, human serum, human urine, and living cancer cells analysis. This study offers a fresh perspective on amperometric sensors based on metal alloys and CDs electrode, highlighting the potential of enzyme-independent detection for hydrogen peroxide in biological systems.

Ultra-sensitive electrochemical detection of levofloxacin using a binder-free copper and graphene composite

Given the levels of pollution in the aquatic environment and the development of antimicrobial resistance, it is essential to develop sensors, with sensitivity, selectivity, stability, and cost-effectiveness, for the determination of antibiotics. The present article highlights the fabrication of an ultra-sensitive graphene and copper sensor, Gr/Cu, supported on glassy carbon (GCE/Gr/Cu) for the electroanalysis of levofloxacin through a cost-effective electrodeposition method. The sequential electrodeposition of graphene and Cu was optimised to give GCE/Gr/Cu, with the Cu particles well dispersed on the graphene sheets. The composite exhibited very good conducting properties as evidenced from electrochemical impedance studies. Using cyclic voltammetry, an impressive sensitivity of 19.7 μA μM−1 cm−2 was achieved with a detection limit of 11.86 nM, providing a promising electrocatalytic material for the determination of this antibiotic. Moreover, good selectivity was observed in the presence of various ions typically found in water and other drug molecules, while very good stability exceeding a 21-day period was achieved, and recovery values between 97.7 and 103.8 % were obtained in tap water.

Synthesis of Cd-Cu nanoparticles supported on HOPG for use as electrocatalytic material for nitrate reduction

Bimetallic nanoparticles application has attracted great attention in the field of electrocatalysis because they can enhance the catalytic properties toward certain reactions of technological interest, such as nitrate reduction. For this purpose, Cd-Cu bimetallic nanoparticles were prepared on highly oriented pyrolytic graphite substrates by sequential electrodeposition of both metals. The process was studied by conventional electrochemical techniques, and the generated deposits were characterized by scanning electron microscopy − energy dispersive X-ray spectroscopy analysis. Initially, Cu nanoparticles were prepared by a simple potentiostatic pulse applied to the carbonaceous substrate. Scanning electron microscopy images showed high density of mainly hemispherical-shaped Cu crystals distributed preferably on step edges and surface defects of the highly oriented pyrolytic graphite electrode. Subsequently, Cd particles were prepared in the same way by immersing the Cu nanoparticles / highly oriented pyrolytic graphite modified substrate in an electrolyte solution containing Cd2+ ions, exploiting the phenomenon of underpotential deposition. It was evidenced that the existing crystals grew in size, most of them showing the typical shapes of those for Cd nanoparticles. The application of the Cd-Cu nanoparticles / highly oriented pyrolytic graphite electrode as a feasible electrocatalyst material for nitrate reduction was investigated by cyclic voltammetry for different nitrate concentrations, also considering the possibility of using this procedure as a method for the anion detection.

Stainless steel as gas evolving electrodes in water electrolysis: Boosting the electrocatalytic hydrogen evolution reaction on electrodeposited Ni@CoP modified stainless steel electrodes

High efficient and durable electrocatalytic electrodes play a vital role in energy conversion and storage. In this concern, water electrolysis technology needs high performance electrodes with high activity and stability to implement this technology for green hydrogen production. Here, this study reports on the development of self-supported electrodes for the hydrogen evolution reaction (HER) based on sequential electrodeposition technique. First, the CoP has been deposited on stainless steel mesh (SSM) electrode followed by deposition of Ni to form Ni@CoP electrocatalysts standing on SSM. The loading amount of Ni was studied to achieve a high catalytic activity. The developed electrodes have been investigated with FE-SEM, EDX, XRD and XPS to identify their morphological properties as well as their chemical states and compositions. Electrocatalytic activity and durability have been studied in alkaline media by different electrochemical methods, such as LSV, EIS and CP. The results showed that the optimum deposition time of 10 min (10Ni@CoP) exhibited the higher catalytic activity in term of overpotential and Tafel slope giving a overpotential of 188 mV at 10 mA cm−2 with a small Tafel slope of 69 mV.dec−1 compared to CoP electrode with overpotential 266 mV and Tafel slope of 105 mV.dec−1 highlighting the role of Ni in enhancing the catalytic activity of the developed electrodes towards HER. Moreover, the Ni@CoP showed high stability under continues electrolysis at 50 and 100 mA.cm−2. These findings have been discussed in light of porous structure of the electrodes and introducing of Ni particles which led to creating more active sites and enhancing the hydrogen adsorption/desorption and thus facilitating the HER kinetics. The facial preparation method of self-supported electrodes and the obtained activity and stability of Ni@CoP electrodes render them as potent electrodes for HER in alkaline water electrolysis.

Morphology-controlled peroxidase-like cuprous oxide-platinum cubes for dual-mode sensing of mercury ions

It is still a challenge to achieve high-precision, rapid, efficient, and accurate detection of toxic mercury ions in complex environmental medium. In this protocol, the controllable and multi-functional Cu2O/Pt cubes were first utilized to construct a colorimetric and photoelectrochemical (PEC) dual-mode sensor for mercury ions. For the colorimetric sensing, compared with Cu2O and Pt particles alone, the Cu2O/Pt cubes creatively prepared by sequential electrodeposition method have simulated peroxidase synergistic catalytic activity against chromophore 3,3′,5,5′-tetramethylbenzidine (TMB) upon exposure to H2O2. Meanwhile, Pt nanoparticles (NPs) can selectively reduce Hg2+ ions, and the resulting Pt-Hg alloys can attenuate the catalytic oxidation. Based on the similar signal suppression strategy, the Cu2O/Pt cubes could also be utilized for PEC sensing of Hg2+ ions since Cu2O is a well-known p-type semiconductor. Based on this unique dual-signal output sensing mechanism, the constructed sensor can be competent for the measurement of Hg2+ in practical settings. This strategy creatively combines the dual functions of Cu2O and Pt to the dual signal expression of sensors. Moreover, the homogeneous distribution of Cu2O/Pt cubes prepared by electrodeposition ensures the stability of dual signal expression, especially for modified electrodes. Additionally, the designed dual-mode sensor has good performance in sensitivity, specificity, simple operation as well as cost-effectiveness and rapid response. In particular, the dual-output sensing strategy enables self-confirmation of detection results, which greatly improves the reliability of the sensor.

Sequential Laser-Burned Lignin and Hydrogen Evolution-Assisted Copper Electrodeposition to Manufacture Wearable Electronics.

In the contemporary world, wearable electronics and smart textiles/fabrics are galvanizing a transformation of the health care, aerospace, military, and commercial industries. However, a major challenge that exists is the manufacture of electronic circuits directly on fabrics. In this work, we addressed the issue by developing a sequential manufacturing process. First, the target fabric was coated with a customized ink containing lignin. Next, a desired circuit layout was patterned by laser burning lignin, converting it to carbon and establishing a conductive template on the fabric. At last, using an in-house-designed printer, a devised localized hydrogen evolution-assisted (HEA) copper electroplating method was applied to metalize the surface of the laser-burned lignin pattern to achieve a very low resistive circuit layout (0.103 Ω for a 1 cm long interconnect). The nanostructure and material composition of the different layers were investigated via scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDX), Raman spectroscopy, and Fourier-transform infrared spectroscopy (FTIR). Monitoring the conductivity change before and after bending, rolling, stretching, washing, and adhesion tests presented remarkable mechanical stability due to the entanglement of the copper nanostructure to the fibers of the fabric. Furthermore, the HEA method was used to solder a light-emitting diode to a patterned circuit on the fabric by growing copper at the terminals, creating interconnects. The presented sequential printing method has the potential for fabricating reliable wearable electronics for various applications, particularly in medical monitoring.

Hierarchical Heterogeneous NiFe Layered Double Hydroxides for Efficient Solar-Powered Water Oxidation.

Highly active, stable, and low-cost oxygen evolution reaction (OER) electrocatalysts are urgently needed for the realization of large-scale industrial hydrogen production via water electrolysis. Layered double hydroxides (LDHs) stand out as one of the most promising nonprecious electrocatalysts worth pursuing. Here, a hierarchical heterogeneous Ni2+Fe3+@Ni2+Fe2+ LDH was successfully synthesized via a sequential electrodeposition technique using separate electrolytes containing iron precursors with different valence states (Fe2+, Fe3+). The underlying highly crystalline Ni2+Fe2+ LDH nanosheet array provides a large surface for the catalytically more active Ni2+Fe3+ LDH overlayer with low crystallinity. The resulting Ni2+Fe3+@Ni2+Fe2+ LDH demonstrates excellent OER activity with overpotentials of 218 and 265 mV to reach current densities of 10 and 100 mA cm-2, respectively, as well as good long-term stability for 30 h even at a high current density of 500 mA cm-2. In an overall water splitting, an electrolyzer using an electrocatalyst of Sn4P3/CoP2 as a cathode requires only a cell voltage of 1.55 V at 10 mA cm-2. Furthermore, the solar-powered overall water splitting system consisting of our electrolyzer and a perovskite/Si tandem solar cell exhibits a high solar-to-hydrogen conversion efficiency of 15.3%.

Cobalt-Based Double Electrodeposited Catalysis for Efficient Oxygen Evolution in Anion Exchange Membrane Water Electrolysis

To produce green hydrogen using anion exchange membrane water electrolysis (AEMWE), high-performance oxygen evolution catalysts are needed. This study presents a novel strategy for increasing the intrinsic and extrinsic activities of Co-based catalysts through sequential electrodeposition of Fe and Co. In a single AEMWE cell, the double-electrodeposited Fe@Co electrode demonstrated a current density of 1,780 mA cm-2 at 1.8V at 50°C. The enhancement of catalytic activity was clearly observed in the Co-Fe pair, but it was not evident in Co catalyst synthesized with other metals. The discovery and analysis of double electroplating provide an innovative approach to non-noble-metal AEMWE, which is an important step toward cost-effective green hydrogen generation.

Preparation of PEGylated uricase attached magnetic nanowires and application for uric acid oxidation.

The present study aims to immobilize the uricase enzyme on magnetic nanowires and to examine its potential for use in the treatment of gout. For this, Au/Ni/Au nanowires were synthesized using a polycarbonate membrane template by the sequential electrodeposition of Au, Ni, and Au, respectively. The uricase enzyme was covalently attached to these nanowires and was also coated with PEG. Optimum enzymatic conditions, kinetic parameters, thermal, storage, and operational stability were determined by performing enzymatic activity tests of free and immobilized uricase. Additionally, the efficacy of both enzyme preparations in artificial human serum and the presence of protease was also investigated. Experimental results showed that immobilized uricase showed higher stability than free uricase in all studied conditions. The potential of immobilized uricase to oxidize uric acid in artificial serum was also investigated and it was found that immobilized preparation demonstrated approximately 6 times higher activity than that of the free enzyme. The results of this study showed that uricase-attached nanowires oxidized uric acid effectively and are promising in the treatment of gout.

A sequential template electrodeposition anodization and in situ aniline electropolymerization-based facile electrochemical synthesis strategy

Herein, we propose a facile continuous electrochemical synthesis strategy to build 3D hierarchical hybrid conductive networks based on sequential template electrodeposition-anodization and in-situ aniline electropolymerization. It was implemented in a tin system to prepare a 3D tin skeleton with micron-scale features using the hydrogen bubble dynamic template method, followed by electrochemical anodization to achieve nanoscale modulation. This well-designed 3D hierarchical metal oxide framework was used for the in-situ electropolymerization of aniline, preserving the hierarchical morphological features while establishing large conductive networks for ultrafast electron transport and enhancing the structural stability of tin dendrites. Regulation of the hierarchical morphologies promotes material surface reactivity, increases the electrochemically active sites, and improves the ion diffusion kinetics, thus solving the “dead surface” problem in the energy storage process. Such multifaceted synergistic strategies of structural modulation and functional hybridization have opened up new ways to design efficient binder-free hybrid electrode materials.

Tailor-designed binary Ni-Cu nano dendrites decorated 3D-carbon felts for efficient glycerol electrooxidation.

Herein, 3D-Carbon Felt (CF) are decorated with nickel-copper (Ni-Cu@CF) bimetallic nanostructures through either sequential or co-electrodeposition tactics. Their catalytic activity towards glycerol electrooxidation is investigated by employing cyclic voltammetry (CV) and linear sweep voltammetry LSV. The morphology and composition of the various Ni-Cu@CF are investigated using X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) together with various electrochemical measurements (e.g., CV, chronoamperometry, LSV). The co-deposition of Ni-Cu shows a dendritic-like structure with higher electrocatalytic activity towards glycerol electrooxidation compared to the monometallic counterparts. Interestingly, the best electrode (NiCu@CF Ni particles as the top layer) prepared by sequential electrodeposition shows 1.6-fold higher glycerol oxidation activity, manifested in oxidation current, compared to Ni-coated CF due to Ni particles covering the surface of dendritic copper uniformly. Thus, the surface concentration of Ni is increased and at the same time a synergistic effect occurs between Ni and Cu by the simple addition of Cu which reinforces the surface concentration of Ni from 3.4 × 10-8 to 1.1 × 10-7 mol cm-2.

Selective Extraction of Silver and Palladium in Leachate Based on EDTA Complexation: Electrodeposition, Nucleation Mechanism, and Kinetic Analysis

The development of green recycling technology for precious metals such as Ag and Pd from secondary resources can prevent environmental pollution caused by improper disposal, and it can alleviate resource shortage and promote sustainable development. Ag and Pd often coexist in some solid waste. This study proposed the extraction of Ag and Pd stepwise from leachate through the green technology of potential-controlled electrodeposition, and the reduction potential difference of Ag and Pd in solution was increased based on EDTA (ethylenediaminetetraacetic acid) complexation. The electrochemical behavior of Ag+ and Pd2+ in solution was investigated. It was determined that the electrodeposition separation of Ag+ and Pd2+ can be achieved with a pH of 9 and an EDTA molar ratio of 1:1.5 in the solution. With sequential electrodeposition at 0 V and −0.7 V, 99.3% of Ag and 96.15% of Pd were recovered, respectively, and their purity was achieved 100%. Pd electrodeposition conformed to three-dimensional instantaneous nucleation and growth mechanism analyzed with the Scharifker–Hills model. Compared with the EDTA-free environment, the diffusion coefficient of ions reduced, and the activation energy of Ag and Pd reduction reaction increased in the EDTA environment. This study provides an environmentally friendly and efficient method for precious metal recovery from secondary resources.

Suppression of Eddy Current Loss in Multilayer NiFe-Polypyrrole Magnetic Cores Fabricated Using a Continuous Electrodeposition Process

Metallic magnetic alloys are of interest as core materials in ultracompact or integrated inductors and transformers. However, when operated at high frequencies, such materials should comprise a multilayer stack of magnetic material laminations and electrically insulating interlayers to suppress eddy current loss. To achieve scalable and continuous fabrication of such a structure, sequential multilayer electrodeposition is an attractive approach. To achieve sequential electrodeposition, interlayer’s electrical conductivity should be sufficiently high to permit electrodeposition of subsequent layers, but sufficiently low to suppress eddy current loss. Polypyrrole, an electrodepositable polymer, was investigated as an interlayer material. Finite element modeling demonstrated a negligible difference in eddy current loss between NiFe/polypyrrole and NiFe/vacuum multilayers. Experimental verification of the efficacy was demonstrated as well. Compared with a single-layer NiFe inductor that has a comparable low-frequency (10 kHz) inductance value, a laminated ten-layer NiFe core showed higher inductance retention (88% of the low-frequency inductance for the laminated core versus 21% for the single-layer core) and lower ac resistance (1.68 versus <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$12.7~\Omega $ </tex-math></inline-formula> ) at 8 MHz, both of which are signs of suppressed eddy current. This scalable fabrication approach to high-frequency inductors will facilitate power converter miniaturizations.

Sequential electrodeposition fabrication of graphene/polyaniline/MnO2 ternary supercapacitor electrodes with high rate capability and cyclic stability

The incorporation of various capacitive materials to fabricate multi-component electrodes has emerged as a feasible methodology toward high-performance supercapacitors. In this paper, a facile two-step electrodeposition method is proposed to construct polyaniline (PANI)/MnO2 hybrid nanostructure on reduced graphene oxide (RGO) matrix for the ternary supercapacitor electrodes. By the sequential potentiostatic methods, PANI is first electropolymerized on RGO hydrogel films before MnO2 granules are electrodeposited on the RGO/PANI conductive substrates to obtain the free-standing composite films. The resulting RGO/PANI/MnO2 ternary composite electrodes present significantly promoted capacitive properties compared with the binary RGO/PANI electrodes. Particularly, the optimized electrode and corresponding all-solid-state device could achieve the high specific capacitances of 942.6 and 205.0 F g–1 at 1 A g–1 with superb capacitance retention of 86.4% and 80.3% at 30 A g–1, respectively. The device delivers a maximum energy density of 41.0 Wh kg–1 and demonstrates outstanding capacitance holdings of 96.1% after 10,000 cycles at 30 A g−1, 87.8% after 5000 cycles at 10 A g−1, and 82.5% after 3000 cycles at 5 A g−1, respectively. The prominent electrochemical performances of the ternary composite can be ascribed to the fact that graphene supplies the conductive matrix to immobilize the active pseudocapacitive constituents, while PANI and MnO2 can compensate each other to surmount the disadvantages of inferior conductivity or stability.

MnO2 nanoparticles advancing electrochemical performance of Ni(OH)2 films for application in electrochromic energy storage devices

In this study, we report a unique material design of interconnected MnO2 nanoparticles covered with a Ni(OH)2 layer as an electrochromic energy storage device. MnO2/Ni(OH)2 electrodes are prepared via sequential electrodeposition within a short duration. During the electrodeposition of Ni(OH)2, the electrodeposited interconnected MnO2 nanoparticles on the substrate provide additional nucleation sites, indicating the porous morphology of the Ni(OH)2 layer without any significant cracks. The synergistic effects generated by the hybrid structure combined with interconnected MnO2 nanoparticles and Ni(OH)2 layer improve the charge transfer kinetics by shortening the transport pathway, facilitating electrochromic performance with fast switching times (2.66 s for bleaching process and 2.72 s for coloring process) and significant transmittance retention. In addition, the energy storage performance of the MnO2/Ni(OH)2 electrode shows an excellent areal capacitance (26.0 mF cm−2 at an operating current density of 0.2 mA cm−2). The electrochromic energy storage device with a two-electrode system (MnO2/Ni(OH)2 as the positive electrode and TiO2 as the negative electrode) exhibits comparable switching times (1.79 s for bleaching time and 3.28 s for coloring time) and areal capacitance (1.21 mF cm−2 at an operating current density of 0.2 mA cm−2) over a wide potential range.

Construction of Hierarchical NiCo2O4@NiFe‐LDH Core‐Shell Heterostructure for High‐performance Positive Electrode for Supercapacitor

AbstractIn this work, the hierarchical NiCo2O4@NiFe‐layered double hydroxide (NiCo2O4@NiFe‐LDH) heterostructure has been successfully synthesized by sequential hydrothermal method, heat treatment and electrodeposition, which is investigated as high‐performance positive electrode for supercapacitor. In this unique structure, on the one hand, the NiCo2O4 as the scaffold provide high conductivity, which accelerates the electron transfer. On other hand, the NiFe‐LDH nanosheets increase the surface area, which offers abundant active sites for electrochemical reaction. Furthermore, the three‐dimensional (3D) hierarchical structures are beneficial to the diffusion for electrolyte ions. Hence, the synergistic effect between NiCo2O4 and NiFe‐LDH endows the optimal NiCo2O4@NiFe‐LDH‐150/CC with excellent electrochemical performance, such as high areal specific capacitance (1.09 F cm−2@1 mA cm−2), small charge‐transfer resistance (0.35 Ω) and superior cycling stability. This study demonstrates the NiCo2O4@NiFe‐LDH core‐shell heterostructures are promising positive electrode material for supercapacitors.