Advanced MXene-based materials for efficient extraction of uranium from seawater and wastewater.

In order to realize the low-carbon development policy, the large-scale development and utilization of nuclear energy is very essential. Uranium is the key resource for nuclear industry. The extracting and recycling uranium from seawater and nuclear wastewater is necessary for secure uranium reserves, ensure energy security, control pollution and protect the environment. The novel nanomaterial MXene possesses the layered structure, high specific surface area, and modifiable surface terminal groups, which allowed it to enrich uranium. In addition, good photovoltaic and photothermal properties improves the ability to adsorb uranium. The excellent radiation resistance of the MAX phase strongly indicates the potential use of MXene as an effective uranium adsorbent. However, there are relatively few reviews on its application in uranium extraction and recovery. This review focuses on the recent advances in the use of MXene-based materials as highly efficient adsorbents for the recovery of uranium from seawater and nuclear wastewater. First, the structural, synthetic and characterization aspects of MXene materials are introduced. Subsequently, the adsorptive properties of MXene-based materials are evaluated in terms of uranium extraction recovery capability, selectivity, and reproducibility. Furthermore, the interaction mechanisms between uranium and MXene absorbers are discussed. Finally, the challenges for MXene materials in uranium adsorption applications are proposed for better design of new types of MXene-based adsorbents.

Hierarchical Nanoheterostructure of HFIP-Grafted α-Fe2O3@Multiwall Carbon Nanotubes as High-Performance Chemiresistive Sensors for Nerve Agents.

New and efficient sensors of nerve agents are urgently demanded to prevent them from causing mass casualties in war or terrorist attacks. So, in this work, a novel hierarchical nanoheterostructure was synthesized via the direct growth of α-Fe2O3 nanorods onto multiwall carbon nanotube (MWCNT) backbones. Then, the composites were functionalized with hexafluoroisopropanol (HFIP) and successfully applied to detect dimethyl methylphosphonate (DMMP)-sarin simulant gas. The observations show that the HFIP-α-Fe2O3@MWCNT hybrids exhibit outstanding DMMP-sensing performance, including low operating temperature (220 °C), high response (6.0 to 0.1 ppm DMMP), short response/recovery time (8.7 s/11.9 s), as well as low detection limit (63.92 ppb). The analysis of the sensing mechanism demonstrates that the perfect sensing performance is mainly due to the synergistic effect of the chemical interaction of DMMP with the heterostructure and the physical adsorption of DMMP by hydrogen bonds with HFIP that are grafted on the α-Fe2O3@MWCNTs composite. The huge specific surface area of HFIP-α-Fe2O3@MWCNTs composite is also one of the reasons for this enhanced performance. This work not only offers a promising and effective method for synthesizing sensitive materials for high-performance gas sensors but also provides insight into the sensing mechanism of DMMP.

Three-Step Depletion Strategy of Glutathione: Tunable Metal-Organic-Framework-Engineered Nanozymes for Driving Oxidative/Nitrative Stress to Maximize Ferroptosis Therapy.

Ferroptosis is a novel type of nonapoptotic programmed cell death involving the accumulation of lipid peroxidation (LPO) to a lethal threshold. Herein, we propose tunable zeolitic imidazolate framework (ZIFs)-engineered biodegradable nanozymes for ferroptosis mediated by both reactive oxygen species (ROS) and nitrogen species (RNS). l-Arginine is utilized as an exogenous nitric oxide donor and loaded into hollow ZIFs@MnO2 artificial nanozymes, which are formed by etching ZIFs with potassium permanganate and simultaneously generating a MnO2 shell in situ. The constructed nanozymes with multienzyme-like activities including peroxidase, oxidase, and catalase can release satisfactory ROS and RNS through a cascade reaction, consequently promoting the accumulation of LPO. Furthermore, it can improve the efficiency of ferroptosis through a three-step strategy of glutathione (GSH) depletion; that is, the outer MnO2 layer consumes GSH under slightly acidic conditions and RNS downregulates SLC7A11 and glutathione reductase, thus directly inhibiting GSH biosynthesis and indirectly preventing GSH regeneration.

Fe-MMT/WO3 composites for chemical and photocatalysis synergistic reduction of uranium (VI).

The preparation of Fe-MMT/WO3 composites by the hydrothermal method has been explored in this study for the construction of a chemical and photocatalytic catalyst for the reduction of U (VI). This research found that the visible light absorption and reduction potential of the Fe-MMT/WO3 composites were relatively superior compared to Fe-MMT and WO3 alone. Based on an evaluation of the performance of the Fe-MMT/WO3 composites under visible light irradiation, it was discovered that they had greater uranium extraction capacity, where the maximum extraction capacity of U (VI) was determined to be 1862.69 mg g-1, with removal efficiency reaching 93.32%. To investigate the electron transfer and U (VI) to U (IV) reduction mechanisms after the composite, XPS and DFT calculations were conducted. Results showed that Fe (II) is converted to a higher state Fe (III) and WO3 produce photoelectrons which together reduce U (VI) to U (IV). Moreover, the photoelectrons partially transferred to Fe-MMT with low reduction potential to reduce Fe (III) to Fe (II), allowing iron cycling during uranium extraction to be achieved.

Co Single Atoms Anchored in N and P Co-doped Porous Carbon Fibers for Efficient Water Splitting.

Single atom catalysts (SACs) show potential application for highly efficient water splitting. Herein, we designed Co single atoms (SAs) dispersed on N and P co-doped porous carbon nanofibers as electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The configuration of Co SAs is proved to coordinate with 4 N/O atoms. The long-range interactions between doped P atoms and Co-N4 (O) sites could modulate the electronic structures of M-N4 (O) sites, which greatly reduce the adsorption energies of HER and OER intermediates at metal sites. Density Functional Theory calculations reveal that CoSA /CNFs exhibits optimized HER and OER kinetics when P coordinates with two N atoms. The atomically dispersed Co electrocatalyst exhibits the low overpotentials of 61, 89 and 390 mV for acidic HER, alkaline HER and OER at 10 mA cm-2 current density, along with the Tafel slope of 54, 143 and 74 mV dec-1 , respectively. This work demonstrates the prospect of utilizing di-heteroatom-doping transition metal SACs, and provides a novel and general strategy for the preparation of SACs.

Dual-inhibition of lactate metabolism and Prussian blue-mediated radical generation for enhanced chemodynamic therapy and antimetastatic effect.

Numerous research studies have proved that lactate is pivotal in tumor proliferation, metastasis, and recurrence, so disrupting the lactate metabolism in the tumor microenvironment (TME) has become one of the effective methods of tumor treatment. Herein, we have developed a versatile nanoparticle (HCLP NP) based on hollow Prussian blue (HPB) as the functional carrier for loading α-cyano-4-hydroxycinnamate (CHC), and lactate oxidase (LOD), followed by coating with polyethylene glycol to enhance chemodynamic therapy (CDT) and the antimetastatic effect of cancer. The obtained HCLP NPs would be degraded under endogenous mild acidity within the TME to simultaneously release CHC and LOD. CHC inhibits the expression of monocarboxylate transporter 1 in tumors, thereby interrupting the uptake of lactate from the outside and alleviating tumor hypoxia by reducing lactate aerobic respiration. Meanwhile, the released LOD can catalyze the decomposition of lactate into hydrogen peroxide, further enhancing the efficacy of CDT by generating plenty of toxic reactive oxygen species through the Fenton reaction. The strong absorbance at about 800 nm endows HCLP NPs with excellent photoacoustic imaging properties. Both in vitro and in vivo studies have demonstrated that HCLP NPs can inhibit tumor growth and metastasis, providing a new possibility for tumor therapy.

Surface hydrolysis-anchored eugenol self-polishing marine antifouling coating.

Traditional self-polishing antifouling coatings kill surface organisms by releasing toxic substances, which are damaging to the ecosystem. As a natural antimicrobial substance, eugenol is environmentally friendly and has been proven by different research teams to be effective in enhancing the anti-fouling effect of coatings in the real sea. While in these previous research works, the eugenol was released directly into the seawater thus cannot further serve as surface antifouling effect, leading to a limited antifouling effect of the coating. In this work, the quaternary ammonium component was introduced into the butyl ester-based resin - poly (eugenol methacrylate - acryloyloxyethyltrimethyl ammonium chloride - hexafluorobutyl methacrylate - methyl methacrylate - butyl methacrylate - ethylene glycol methyl ether acrylate) (EMQFP) coating for the first time by simple one-step free radical polymerization method. On the one hand, the eugenol produced by hydrolysis is anchored to the quaternary ammonium on the coating surface for a period of time due to the cationic-π interaction, instead of being released into seawater immediately after hydrolysis, thus increasing the utilization rate of eugenol; on the other hand, the negatively charged carboxylate groups generated after hydrolysis in the coating are mutually attracted to quaternary ammonium through electrostatic effect, so the resin chain segment conformation on the coating surface adjusted to produce zwitterionic-like structure, and the hydration of zwitterionic inhibits primary fouling adhesion.

Z-scheme heterojunction ZnS/WO3 composite: Photocatalytic reduction of uranium and band gap regulation mechanism.

In the present research, ZnS/WO3 composites were prepared by coprecipitation method to construct the Z-scheme heterojunction photocatalyst with high efficiency electron separation for the photocatalytic reduction of U(VI). Compared with WO3 and ZnS, the visible light absorption, photoreduction ability and photocatalytic activity of ZnS/WO3 composites were improved. The ZnS/WO3 composites show higher photoreduction U(VI) performance under visible light irradiation with the maximum extraction capacity of U(VI) at 1.52 g g-1. The ZnS/WO3 composites exhibit high uranium reduction ability under natural light with removal efficiency reaching 93.4 %. In-situ monitoring experiments and DFT calculations were designed to explore the mechanism and pathway of photoelectron transfer in the reduction process from U(VI) to U(IV). The results show that ZnS/WO3 has an internal electric field to form a Z-scheme electron transfer, and uranium reduction is a dual-electron transfer pathway. In addition, the band gap regulation mechanism of binary composite semiconductor materials is deeply discussed.

A high-flux antibacterial poly(amidoxime)-polyacrylonitrile blend membrane for highly efficient uranium extraction from seawater.

Uranium is an important fuel for nuclear power, with 4.5 billion tons of it stored in the oceans, 1,000 times more than on land. Polymer membrane materials are widely used in the marine resources fields, due to their convenient collection, good separation and can work continuously. Herein, a poly(amidoxime)-polyacrylonitrile blend membrane (PCP) with high flux, excellent antibacterial properties and uranium adsorption performance has been prepared by using the phase inversion method, and the prepared membrane was used for highly efficient uranium extraction from seawater. In static adsorption experiments, the PCP membrane reached adsorption equilibrium after 48 h, and the adsorption capacity was 303.89 mg/g (C0 =50 mg/L). In dynamic adsorption experiments, it was found that the lower flow rate and higher number of membrane layers were favorable for dynamic adsorption. In addition, the water flux of the PCP membrane was 7.4 times higher than that of the PAN membrane. The adsorption mechanism can be attributed to the chelation between amino and hydroxyl groups in CS, amidoxime group in poly(amidoxime) and uranyl ions. The simple preparation process coupled with the excellent adsorption performance indicated that the PCP membrane would be a promising material for the uranium extraction from seawater.

Theory-Guided Design of a Method to Obtain Competitive Balance between U(VI) Adsorption and Swaying Zwitterion-Induced Fouling Resistance on Natural Hemp Fibers.

The competitive balance between uranium (VI) (U(VI)) adsorption and fouling resistance is of great significance in guaranteeing the full potential of U(VI) adsorbents in seawater, and it is faced with insufficient research. To fill the gap in this field, a molecular dynamics (MD) simulation was employed to explore the influence and to guide the design of mass-produced natural hemp fibers (HFs). Sulfobetaine (SB)- and carboxybetaine (CB)-type zwitterions containing soft side chains were constructed beside amidoxime (AO) groups on HFs (HFAS and HFAC) to form a hydration layer based on the terminal hydrophilic groups. The soft side chains were swayed by waves to form a hydration-layer area with fouling resistance and to simultaneously expel water molecules surrounding the AO groups. HFAS exhibited greater antifouling properties than that of HFAO and HFAC. The U(VI) adsorption capacity of HFAS was almost 10 times higher than that of HFAO, and the max mass rate of U:V was 4.3 after 35 days of immersion in marine water. This paper offers a theory-guided design of a method to the competitive balance between zwitterion-induced fouling resistance and seawater U(VI) adsorption on natural materials.

Mussel-inspired polydopamine microspheres self-adhered on natural hemp fibers for marine uranium harvesting and photothermal-enhanced antifouling properties.

The rapid development of nuclear energy and the accelerated consumption of uranium (U(VI)) ores have forced researchers to turn to marine U(VI) harvesting. However, the performance of marine U(VI) harvesting materials was challenged by the combination of ultralow concentrations of U(VI), high concentrations of various interfering ions and biofouling from abundant marine living organisms. Natural abundant hemp fibers (HFs) were adhered by mussel-inspired polydopamine microspheres (HFMPDA) during self-polymerization. Both HFs and PDA are derived from natural products with low-cost and eco-friendly properties to guarantee compatibility with biological marine environments. HFMPDA exhibits an outstanding distribution coefficient of 10.51 ± 0.51 L g-1 for U(VI) and great fouling resistance. The coordination forms between the U(VI) ion and HFMPDA were investigated by density functional theory (DFT), and the antifouling property was simulated by molecular dynamics (MD) calculations. The adsorption capacity of HFMPDA is 128.43 ± 3.26 µg g-1, which is 1.75 and 6.05 times higher than that of HFPDA (only covered by PDA) and V(V), respectively, after immersion for 34 days in the Yellow Sea, China. These polydopamine microspheres adhered to HF will be a photothermal marine U(VI) harvesting material with enhanced selectivity and fouling resistance.

MOF-derived electrochemical catalyst Cu-N/C for the enhancement of amperometric oxygen detection.

Electrochemical sensors using ionic liquids as electrolytes for oxygen detection are now getting more and more attention. Recently, an ionic liquid combined with an electrochemically active catalyst system has become popular for boosting the sensing performance of oxygen sensors. In this work, the imidazolyl-based ionic liquid 1-butyl-2,3-dimethylimidazole bis((trifluoromethyl)sulfonyl)imide [Bmmim][TFSI] is first prepared by a facile two-step method. Subsequently, a transition metal and N-codoped porous carbon oxygen reduction electrochemical catalyst Cu-N/C is synthesized by calcining the Cu-doped ZIF-8 precursor and then blending it in different ratios with the ionic liquid [Bmmim][TFSI] as composite electrolytes for oxygen detection. The composite electrolyte Cu-N/C/[Bmmim][TFSI] exhibits increased responses in cyclic voltammetry (CV) and chronoamperometry (CA) relative to that of the pure ionic liquid. Furthermore, the CV and CA data show that 6% Cu-N/C/[Bmmim][TFSI] has the optimum oxygen sensing response with an enhanced reduction peak current, a sensitivity of 0.1678 µA/[% O2] and a good linear fitting coefficient of 0.9991. In conclusion, the results confirm the success of using Cu-N/C as an electrochemical catalyst composed of the Cu-N/C/[Bmmim][TFSI] electrolyte for improving the responsivity, stability and sensitivity towards a wide range of oxygen concentrations.

Biodegradable Nanocatalyst with Self-Supplying Fenton-like Ions and H2O2 for Catalytic Cascade-Amplified Tumor Therapy.

Therapeutic nanosystems triggered by a specific tumor microenvironment (TME) offer excellent safety and selectivity in the treatment of cancer by in situ conversion of a less toxic substance into effective anticarcinogens. However, the inherent antioxidant systems, hypoxic environment, and insufficient hydrogen peroxide (H2O2) in tumor cells severely limit their efficacy. Herein, a new strategy has been developed by loading the chemotherapy prodrug disulfiram (DSF) and coating glucose oxidase (GOD) on the surface of Cu/ZIF-8 nanospheres and finally encapsulating manganese dioxide (MnO2) nanoshells to achieve efficient DSF-based cancer chemotherapy and dual-enhanced chemodynamic therapy (CDT). In an acidic TME, the nanocatalyst can biodegrade rapidly and accelerate the release of internal active substances. The outer layer of MnO2 depletes glutathione (GSH) to destroy the reactive oxygen defensive mechanisms and achieves continuous oxygen generation, thus enhancing the catalytic efficiency of GOD to burst H2O2. Benefiting from the chelation reaction between the released Cu2+ and DSF, a large amount of cytotoxic CuET products is generated, and the Cu+ are concurrently released, thereby achieving efficient chemotherapy and satisfactory CDT efficacy. Furthermore, the release of Mn2+ can initiate magnetic resonance imaging signals for the tracking of the nanocatalyst.

Surface hybridization of π-conjugate structure cyclized polyacrylonitrile and radial microsphere shaped TiO2 for reducing U(VI) to U(IV).

It is still a challenge to obtain uranium (U) adsorbents with high selectivity, excellent cycle stability and excellent performance through design and synthesis. In this paper, the TiO2/CPAN-AO catalyst was prepared by the hydrothermal method combined with high temperature cyclization dehydrogenation. TiO2/CPAN-AO has excellent photocatalytic properties, which can reduce U(VI) to U(IV) quickly and selectively. The generated Z-type heterojunction promotes the reduction ability of photogenerated electrons, and obtains great selectivity to UO22+ (Uranyl ions) through the AO group. TiO2/CPAN-AO with π-electron conjugated structure broadens the spectral range through surface hybridization and prolongs the lifetime of photo-generated charges. Under the induction of light, the uranium extraction capacity of TiO2/CPAN-AO after 5 h of irradiation is about 2.38 g/g. TiO2/CPAN-AO is a catalyst with enhanced adsorption capacity, making it possible to extract uranium from large-scale natural seawater in the future.

Three-dimensional heterostructured polypyrrole/nickel molybdate anchored on carbon cloth for high-performance flexible supercapacitors.

The urgent demands of energy storage for wearable electronics necessitates the development of flexible supercapacitors (FSCs). However, the service environment of portable/wearable devices requires supercapacitors to possess excellent mechanical properties to withstand harsh straining conditions, such as bending, rolling, and twisting. Hence, to develop a high-performance flexible supercapacitor (FSC) that possesses both superior electrochemical properties and remarkable mechanical capacities is still a formidable challenge. In this paper, we successfully fabricate a 3D heterostructured electrode with bulge structured polypyrrole (PPy) wrapped NiMoO4 nanowires on carbon cloth (CC). Benefiting from the 3D heterostructure and the synergistic effect between NiMoO4 and PPy, the PPy/NiMoO4/CC electrode shows a high areal capacitance of 3.4 F cm-2 and cyclic stability (94% capacitance retention). Moreover, the assembled PPy/NiMoO4/CC//activated carbon (AC)/CC device exhibits a high energy density (0.5 mW cm-2 at a power density of 3.7 mWh cm-2). Furthermore, the CV curves of PPy/NiMoO4/CC//AC/CC show no obvious change under miscellaneous deformation conditions, indicating good flexibility. This work demonstrates that the assembled PPy/NiMoO4/CC//AC/CC FSC possesses notable electrochemical properties and exhibits great potential for application in future wearable energy-storage devices.

Anti-Biofouling and Water-Stable Balanced Charged Metal Organic Framework-Based Polyelectrolyte Hydrogels for Extracting Uranium from Seawater.

Metal-organic frameworks (MOFs) are diffusely defined as a promising class of porous material for uranium extraction from seawater, but there are still challenges in their stability and anti-biofouling performance. Herein, a water-stable and anti-biofouling ZIF-67/SAP0.45 composite hydrogel was reported by the sequential processes of electrostatic interactions between the oppositely charged polymer, ionic gelation, and template growth of ZIF-67 crystals. Entanglement of positively charged polyethyleneimine (PEI) and negatively charged sodium alginate (SA) polymer chains provided external porosities, anti-biofouling properties, and mechanical support for the hydrogels and further reduced the possibility of ZIF-67 aggregation. The neutral composite hydrogel possessed the least Nitzschia on the surface after 7 days contact, which endows the adsorbent with a high uranium uptake capacity of 2107.87 ± 41.64 µg g-1 at 1 mg L-1 uranium-containing seawater with 8.6 × 105 mL-1 Nitzschia. Additionally, this adsorbent showed water stability with an uranium uptake capacity of 232.88 ± 8.02 mg g-1 even after five adsorption-desorption cycles because of the excellent preparation method. Benefitting from the distinctive hierarchical structure and large accessible surface area, the resultant adsorbent achieved a high uranium capacity of 6.99 ± 0.26 mg g-1 in real seawater. This flexible and scalable approach made the MOF/SAP composite hydrogel a highly desirable uranium adsorbent.

Ionic liquid combined with NiCo2O4/rGO enhances electrochemical oxygen sensing.

Ionic liquids are promising electrolytes for electrochemical gas sensors that have unique physicochemical properties such as negligible vapor pressure and high thermal stability. The modification of ionic liquid (IL) by combining metal oxide with reduced graphene oxide (rGO) is an effective method to improve its gas-sensing properties. In this study, the mesoporous structure of NiCo2O4/rGO is synthesized by simple one-step method, and the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) is mixed with it to form the composite material NiCo2O4/rGO/[BMIM][PF6]. Electrochemical test results indicate that the three electrolytes exhibit response current and long-term stability in the oxygen environment. The oxygen sensor based on NiCo2O4/rGO/[BMIM][PF6] significantly improves the response current and working stability of pure ionic liquid. The sensitivity of the sensor is 0.1087 µA/[%O2], and the linear regression coefficient of the reduction peak current calibration curve is 0.9995. After continuous cyclic voltammetry, the reduction peak current remains at 90% of the initial current value. The interaction of IL and NiCo2O4/rGO significantly enhances electrochemical oxygen sensing performance.

Mussel-inspired anti-biofouling and robust hybrid nanocomposite hydrogel for uranium extraction from seawater.

A major challenge of uranium extraction from seawater (UES) is to effectively block the biofouling without destroying the ecological balance, especially prevent the attachment of macroalgae on the surface of the adsorbent. Herein, a robust montmorillonite-polydopamine/polyacrylamide nanocomposite hydrogel is reported by a two-step method, including PDA intercalation MMT and further free radical polymerization with AM monomers. The interpenetrating structure of hydrogel lead to high water permeability with the swelling ratio of 51, which could fully facilitate the internal accessible sites exposure and increase the uranium diffusion. As a result, a high adsorption capacity of 44 mg g-1 was achieved in lab-scale dynamic adsorption. Most importantly, the prepared anti-biofouling hydrogel adsorbents display excellent anti-adhesion ability towards Nitzschia after 8 days contact. The adsorption capacity of uranium can reach 2130 µg g-1 in algae-contained simulated seawater. This hydrogel also exhibited a long service life of acceptable mechanical strength and adsorption capacity after at least 6 adsorption-desorption cycles. This new anti-biofouling nanocomposite hydrogel shows great potential as a new generation adsorbent for UES.

Rationally designed CuCo2O4@Ni(OH)2 with 3D hierarchical core-shell structure for flexible energy storage.

Composite electrodes that possess both rational structures and appropriate integration are needed to deliver high electrochemical performance in energy storage devices. In this paper, a flexible and binder-free electrode material based on a heterogeneous core-shell structure of CuCo2O4@Ni(OH)2 nanosheets grown on carbon cloth was fabricated by a simple method. The unique three-dimensional hierarchical structure gives the electrode a large specific surface area, which enables rapid response and increases of specific capacitance. The CuCo2O4@Ni(OH)2/carbon fiber cloth (CFC) composite electrode exhibited a specific capacitance of 2160 F g-1 at 1 A g-1 and a good rate capability energy of 82.7% at 20 A g-1. A flexible all-solid-state asymmetric supercapacitor (FAASC) was assembled with the CuCo2O4@Ni(OH)2/CFC electrode as the positive electrode, and activated carbon (AC)/CFC as the negative electrode. This device showed both a high energy density and power density (58.9 W h kg-1 at a power density of 400 W kg-1), and good long-term cycling stability. Furthermore, the assembled CuCo2O4@Ni(OH)2/CFC//AC/CFC devices were capable of driving a blue light-emitting diode after a short charge. The remarkable performance of this CuCo2O4@Ni(OH)2/CFC electrode indicates that this heterogeneous structure has great potential for applications in flexible high-performance energy storage devices.

Layer-by-layer inkjet printing GO film and Ag nanoparticles supported nickel cobalt layered double hydroxide as a flexible and binder-free electrode for supercapacitors.

Inkjet printing is an attractive technique in the field of flexible electronics due to the direct writing, digital controls and non-contact operation process. In this work, we successfully printed graphite oxide and Ag nanoparticles on the substrate of flexible carbon cloth to form a flexible, conductive and hydrophilic layer, which could be used as a new substrate with an electron transport layer of large surface area. In addition, Ni-Co LDH nanosheets as the main active materials were synthesized for improving the electrochemical activity via a convenient electrochemical deposition method. The binder-free Ni-Co LDH/Ag/rGO@CC electrode exhibits outstanding electrochemical performance along with a high capacity of 173 mA h g-1 at 1 A g-1. Moreover, an asymmetric supercapacitor (ASC) was assembled with Ni-Co LDH/Ag/rGO@CC electrode as the positive electrode materials and activated carbon coated CC as the negative electrode materials, showing a high capacity of 95 mA h g-1 at 0.6 A g-1, and maximum energy density of 76 Wh kg-1 at a power density of 480 W kg-1.