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Layered double hydroxides are considered promising electrode materials for the preparation of high-energy-density supercapacitors owing to their suitable microstructure and significant electrochemical properties. In this study, honeycomb-like NiMn-layered double-hydroxide (NiMn-LDH) nanosheet arrays with numerous electron/ion channels, a large number of active sites, considerable redox reversibility, and significant electrical conductivity were synthesized by combining Co

Metal-organic frameworks (MOFs) are attracting tremendous research interest because of their rich redox sites and high specific area which are beneficial for the energy storage applications. Nevertheless, the poor conductivity, low mechanical strength and unsatisfactory capacity severely hinder their wide application. Hence, it is of practical significance to design highly efficient and facile strategy to solve these issues. Herein, vertically oriented ZnO nanorod arrays are applied as precursor to synthesize laminated scale-like and highly-oriented Ni/Zn-MOF/ZnO nanocomposite. Owing to the desirable conductivity resulting from the doping nickel ions and the interaction between ZnO and its relative MOF, the fabricated 0.3Ni/Zn-MOF/ZnO@CC electrode exhibits an electrochemical capacitance of 1693 mF cm

The combination of layered nanorod arrays with unique core–shell structure and transition metal layered double hydroxide (LDH) is considered as a feasible solution to improve the electrochemical performances of capacitor electrode. In this study, layered ZnNiFe-LDH@Cu(OH)2/CF core–shell nanorod arrays, which consist of ultrathin ZnNiFe-LDHs nanosheet shells and ordered Cu(OH)2 nanorod inner cores, are successfully designed and fabricated by a typical hydrothermal way and a simple in situ oxidation reaction. The electrode prepared using ZnNiFe-LDH@Cu(OH)2/CF nanomaterial reveals an remarkable area capacitance of 6100 mF cm−2 at 3 mA cm−2 current density, which is excellently superior than those of ZnFe-LDH@Cu(OH)2/CF, NiFe-LDH@Cu(OH)2/CF, Cu(OH)2/CF and CF. Additionally, the capacitance retention remains as high as 83.4% after 5000 cycles and a very small Rs (0.567 Ω) can be observed. In addition, an asymmetric supercapacitor device is successfully fabricated employing ZnNiFe-LDH@Cu(OH)2/CF. Meanwhile, the ZnNiFe-LDH@Cu(OH)2/CF//AC device can achieve an energy density of 44 Wh kg−1 and a corresponding power density of 720 W kg−1 and possess the capability to light up a multi-function monitor for 33 min just using two ASC equipments connected in series. Therefore, the prepared ZnNiFe-LDH@Cu(OH)2/CF composite materials with unique structure has great application potential in energy storage devices.

The excellent electrical conductivity of graphene is due to its highly-conjugated structures. Manipulation of the electronic and mechanical properties of graphene can be achieved by controlling the destruction of its in-sheet conjugation system. Herein, we report the preparation of CoCeSx -SA@BPMW@RGO through π-π stacking interactions at the molecular level. In this study, sodium alginate was reacted with Co2+ and Ce3+ , and the composite was loaded onto a graphene surface. The graphene sheets were prepared using a bi-pyrene terminated molecular wire (BPMW) to avoid re-stacking of the grapheme sheets, thereby forming nanoscale spaces between sheets. The angle between the BPMW coplanar pyrene group and the phenyl group was 33.2°, and the graphene layer is supported in an oblique direction. Finally, a three-dimensional porous composite was obtained after annealing and vulcanization. The obtained CoCeSx -SA@BPMW@RGO exhibited excellent electrical conductivity and remarkable cycle stability. When the current density was 1 A g-1 , its specific capacitance was as high as 1004 F g-1 . BPMW modifies graphene through the synergistic effect of π-π stacking interaction and special structure to obtain excellent electrochemical performance. Moreover, a solid-state asymmetric supercapacitor device was fabricated based on the synthesized CoCeSx -SA@BPMW@RGO hybrid, which exhibited a power density of 979 W kg-1 at an energy density of 23.96 Wh kg-1 .

Graphene quantum dots (GQDs) are attractive fluorescent nanoparticles that have wide applicability, are inexpensive, nontoxic, photostable, water-dispersible, biocompatible and environmental-friendly. Various strategies for the synthesis of GQDs have been reported. However, simple and efficient methods of producing GQDs with control over the size of the GQDs, and hence their optical properties, are sorely needed. Herein, an ultra-fast and efficient laser writing technique is presented as a means to produce GQDs with homogeneous size from graphene produced by the instantaneous photothermal gasification and recrystallization mechanism. Controlling the laser scan speed and output power, the yield of GQDs can reach to be about 31.458 mg/s, which shows promising potential for large-scale production. The entire process eliminates the need for chemical solvents or any other reagents. Notably, the prepared laser writing produced GQDs (LWP-GQDs) exhibit blue fluorescence under UV irradiation of 365 nm and the Commission Internationale de L’Eclairage (CIE) chromaticity coordinates is measured at (0.1721, 0.123). Overall, this method exhibits superior advantages over the complex procedures and low yields required by other existing methods, and thus has great potential for the commercial applications.

MXene is a neoteric type of bidimensional (2D) transition metal carbide/nitride with broad application prospects, in particular with electrochemical energy storage. The electrochemical performance of MXene is unsatisfactory because it is easy to stack resulting in the difficulty of electrolyte penetration and ion transport. In this study, the cobaltous sulfide-modified 3D MXene/N-doped carbon foam (CoS@MXene/CF) hybrid aerogel is projected and manufactured via simple in situ growth and thermal annealing strategies. The capacitance of the as-fabricated 300-CMC-31:1 electrode material reaches 250 F g-1 (1 A g-1), which is obviously higher than those of MXene, CoS@CF, 400-CMC-31:1, 300-CMC-10:1, 300-CMC-50:1, CF, and MXene/CF electrode materials. Moreover, it can hold 97.5% of the original capacitance after 10,000 cycles and the internal resistance (Rs) is only 0.50 Ω. A green bulb can be lit by two all-solid asymmetric supercapacitors installed in series. The prepared CoS@MXene/CF hybrid aerogel exhibits promising potential for practical application in energy storage areas.

Layered double hydroxides (LDHs) are widely used as cathode materials for supercapacitors (SCs), thanks to their many advantages. However, the single metal species with limited active sites limit the further improvement of the electrochemical performance of LDH materials. We successfully in situ embedded cobalt sulfide quantum dots (Co9S8-QDs) between the layers of ternary metal LDHs derived from metal–organic-frameworks (MOFs) by selective vulcanization of Co. The prepared Ni3Mn1Co@Co9S8-QDs/NF nanocomposites retain the advantages of LDH materials, such as lower charge transfer resistance. At the same time, the selectively generated ultra-small sized Co9S8-QDs reveal more active sites, which complies with the size minimization strategy, leading to the largely enhanced electrochemical properties. Due to the cooperative effect of LDHs and Co9S8-QDs, the prepared electrode has an excellent capacity (492.1 mA h g−1 at 1 A g−1), remarkable equivalent series resistance (0.499 Ω) and superior capacity retention (90.4% after 10 000 charge–discharge cycles). In addition, the carbon coated Fe2O3 nanoarray is prepared on carbon cloth (CC) as the cathode electrode (Fe2O3@C/CC), and the prepared Ni3Mn1Co@Co9S8-QDs/NF//Fe2O3@C/CC all solid-state asymmetric supercapacitor (ASC) shows an outstanding energy density (71.48 W h kg−1) when the power density is 750 W kg−1 and excellent capacity retention (93.7% after 10 000 charge–discharge cycles). As a result, the construction of composite electrodes with polymetallic LDHs and in situ embedded quantum dots should envision broad prospects.

Layered double hydroxides (LDHs) are a kind of classic pseudocapacitive materials with lamellar structure and large specific surface area, which have attracted swinging attention in the electrochemical energy storage area. The CoS2@Ni is synthesized through a hydrothermal process, followed by surface generation of the flower-like nickel-iron layered double hydroxide (NiFe-LDH) nanospheres through a hydrothermal process, which is directly used to design a binder-free electrode with a splendid capacitance capability. The as-synthesized NiFe-LDH@CoS2@Ni electrode presents an outstanding specific capacitance of 11.28 F cm-2 (3880 F g-1) at 2 mA cm-2 (1.17 A g-1) in a three electrodes system. Also, the all-solid-state asymmetric supercapacitor (ASC) is combined utilizing the NiFe-LDH@CoS2@Ni hybrid as the positive electrodes and active carbon covered Ni foam as negative electrodes, respectively. The as-fabricated ASC exhibits a high energy density of 15.84 Wh kg-1 at the power density of 375.16 W kg-1 and can be able to lighten a blue LED indicator for more than 30 minutes, revealing that the prepared NiFe-LDH@CoS2@Ni owns great potential in the aspect of practical applications. Therefore, the prepared NiFe-LDH@CoS2@Ni with outstanding electrochemical properties could be applied for high-performance supercapacitors.

NiCo-LDH has attracted increasing attention in recent years for application in supercapacitors (SCs) owing to its high redox activity and intercalating capability. However, the pristine NiCo-LDH is...

Supercapacitors have attracted tremendous research interest, since they are expected to achieve battery-level energy density, while having a long calendar life and short charging time. Herein, a novel asymmetric supercapacitor has been successfully assembled from NiCo2 S4 nanosheets and spinous Fe2 O3 nanowire modified hollow melamine foam decorated with polypyrrole as positive and negative electrodes, respectively. Owing to the well-designed nanostructure and suitable matching of electrode materials, the assembled asymmetric supercapacitor (ASC) exhibits an extended operation voltage window of 1.6 V with an energy density of 20.1 Wh kg-1 at a power density of 159.4 kW kg-1 . Moreover, the ASC shows stable cycling stability, with 81.3 % retention after 4000 cycles and a low internal resistance of 1.03 Ω. Additionally, a 2.5 V light-emitting diode indicator can be lit up by three ASCs connected in series; this provides evidence of the practical application potential of the assembled energy-storage system. The excellent electrochemical performances should be credited to the significant enhancement of the specific surface area, charge transport, and mechanical stability resulting from the unique 3D morphology.

A fiber asymmetric supercapacitor system is designed with NiCo-LDH nanoflakes and FeOOH nanosheets anchored on electrochemically activated graphite fibers as positive electrode and negative electrode, respectively. Due to the formation of C O Metal bonding, the oxygen-functionalized carbon on electrochemically activated graphite fibers can bind strongly with NiCo-LDH and FeOOH, which assists in establishing the fast electron transfer routes and fluent ion transport avenues. Both NiCo-LDH and FeOOH anchored on electrochemically activated graphite fibers display a high rate performance, 80% and 87.3% of the electric capacity can be reserved with the current density increasing from 2 to 20 A g−1 and 2 to 10 A g−1, respectively, while the NiCo-LDH and FeOOH deposited on untreated graphite fibers can only retain 45% and 40%. The fabricated novel solid-state fiber asymmetric supercapacitor device exhibits an expanded operation potential window of 1.8 V with a maximum energy density (130 W h kg−1) when the power density is 1.8 kW kg−1. Furthermore, a high energy density (81 W h kg−1) is still achieved at a superhigh power density (10.8 kW kg−1). Additionally, a good cycling stability of the solid-state fiber asymmetric supercapacitor can be obtained (90% capacity retention after 10,000 cycles).

S and N co-doped reduced graphene (S–N-rGO) nanohybrids were prepared by a one-step oil bath heating process using glutathione (GSH) as a green and mild co-reduction agent and a S and N source. It can be applied in the field of adsorption for the removal of methylene blue (MB) from aqueous solutions. The efficient adsorption rate of S–N-rGO hybrids for MB (50 mg L−1) was observed with the best even within 2′07′′ from blue solutions into colorless (the mass ratio GO : GSH = 60 : 200). Under this mass ratio, the effects of initial solution pH, temperature, initial concentration and contact time on adsorption towards MB were explored systematically. The results indicated that the adsorption capacity at 275 K could reach up to 598.8 mg g−1, the adsorption behavior followed the pseudo-second-order kinetic model and the equilibrium adsorption data fitted the Langmuir isotherm well. Thermodynamic and kinetic analyses revealed that adsorption is an exothermic, spontaneous and physisorption process.

Environmentally harmful and high-priced initiators such as azodiisobutyronitrile, perchloric acid and butyllithium are usually essential for most of the polymerization technologies such as radical, cationic and anionic polymerizations. Besides, it is also troublesome to achieve complete separation of initiators from the obtained polymers. Herein, a recyclable catalytic system for the generation of hydroxyl radicals by catalyzing hydrogen peroxide based on bi-nano-bionic enzymes (refers to the bionic enzymes constructed from two kinds of enzymes, Fe3O4@Au NPs) was successfully constructed. The magnetic and flower-like Fe3O4 NPs provided a recyclable and well-dispersed scaffold for immobilization of Au NPs, leading to enhanced catalytic activity of Au bionic enzymes. The designed catalytic system showed excellent catalytic activity for hydroxyl radical generation under various working conditions (pH 7–11, 15–100 °C). Impressively, the catalytic system was then employed as a novel initiating system (Fe3O4@Au NPs/H2O2) for reversible addition–fragmentation chain transfer (RAFT) polymerization of a wide range of functional monomers using different RAFT agents in both aqueous and organic solvents. The established initiating system provided an effective method for RAFT polymerization with a real-time control feature in a recyclable way by magnetic separation. It was found that over 93.9% catalytic activity of Fe3O4@Au was still retained after 4 consecutive operations of RAFT polymerization.

Aqueous Zinc-ion batteries (ZIBs), using zinc negative electrode and aqueous electrolyte, have attracted great attention in energy storage field due to the reliable safety and low-cost. A composite material comprised of VO2·0.2H2O nanocuboids anchored on graphene sheets (VOG) is synthesized through a facile and efficient microwave-assisted solvothermal strategy and is used as aqueous ZIBs cathode material. Owing to the synergistic effects between the high conductivity of graphene sheets and the desirable structural features of VO2·0.2H2O nanocuboids, the VOG electrode has excellent electronic and ionic transport ability, resulting in superior Zn ions storage performance. The Zn/VOG system delivers ultrahigh specific capacity of 423 mAh·g−1 at 0.25 A·g−1 and exhibits good cycling stability of up to 1,000 cycles at 8 A·g−1 with 87% capacity retention. Systematical structural and elemental characterizations confirm that the interlayer space of VO2·0.2H2O nanocuboids can adapt to the reversible Zn ions insertion/extraction. The as-prepared VOG composite is a promising cathode material with remarkable electrochemical performance for low-cost and safe aqueous rechargeable ZIBs.

Flexible electronic devices constitute a rapidly rising industry since they can potentially renovate the way humans communicate and interact with external environments. Recently, flexible fiber-shaped supercapacitors have shown great potential in wearable and portable electronics. Herein, a new type of flexible coaxial fiber-shaped asymmetric supercapacitor (FASC) is successfully constructed utilizing a well-aligned Mn, Ni co-substituted Co carbonate hydroxide nanoneedle array on a carbon fiber (MnNiCo-CH/CF) as the positive electrode and an activated carbon (AC) as the negative electrode. Impressively, the MnNiCo-CH/CF electrode with a hierarchical nanostructure exhibits a high specific capacitance of 1440.52 F g−1 at 1 A g−1 and superb cycling stability (90.78%), while the as-fabricated coaxial FASC exhibits a large specific capacitance of 96.13 F g−1 (1 A g−1) and a high energy density of 30.04 W h kg−1 at a power density of 749.97 W kg−1. Moreover, the integration of a few FASCs in series or in parallel is demonstrated to meet the energy and power needs in various practical applications, such as powering shunt-wound LEDs or stitching into cotton fabrics to charge LED electronic displays. Therefore, the successful fabrication of practicable and ultra-flexible FASCs may realize broad applications in future flexible energy storage devices.

The excellent electrical conductivity of graphene is due to its highly-conjugated structures. Manipulation of the electronic and mechanical properties of graphene can be achieved by controlling the destruction of its in-sheet conjugation system. Herein, we report the preparation of CoCeS

The combination of layered nanorod arrays with unique core-shell structure and transition metal layered double hydroxide (LDH) is considered as a feasible solution to improve the electrochemical performances of capacitor electrode. In this study, layered ZnNiFe-LDH@Cu(OH)

The development for environmentally friendly energy conversion and storage equipment has given rise to tremendous research efforts as a result of the growing requirements for environmental friendly resources and the rapid consumption of traditional fossil fuel. Herein, a novel hierarchical CoO/NiO-Cu@CuO heterostructure is successfully devised and synthesized. Cobalt/nickel ions are used to generate novel CoO/NiO-doped laminated CuO nanospheres through the facile in situ wet oxidation combined with cation exchange and calcination strategies. As a result, the electrochemical supercapacitance of the as-prepared CoO/NiO-Cu@CuO electrode can reach 875 C cm-2 (2035 mF cm-2), which exhibits much better electrochemical performance compared to other precursor electrodes at a same current density of 2 mA cm-2. Moreover, an excellent rate capacity of 1395 mF cm-2 (50 mA cm-2) can be achieved when measured at a relative high current density; 90.3% of the initial supercapacitance remains even after 5000 cycles. Furthermore, the as-prepared hierarchical hybrid of laminated CoO/NiO-CuO nanospheres in situ generated on three-dimensional (3D) porous Cu foam is applied to prepare a solid-state asymmetric supercapacitor equipment unit. The fabricated equipment unit shows an energy density of 69.3 W h kg-1 at a power density of 1080 W kg-1. Additionally, the commercially applied 2.5 V light-emitting-diode indicator with blue light can be energized for 4 min when two as-fabricated supercapacitor devices are in series connection. The unique hierarchical heterostructure of the novel laminated nanospheres combined with the 3D grid structure brings about the outstanding electrochemical capacitor performances. This strategy for the fabrication of hierarchical heterostructure electrodes could have an enormous potential for high-performance electrochemical equipment.

Compressible and flexible supercapacitors have aroused enormous interest of many scientific researchers for potential applications in wearable electronic products. However, the design and construction of the electrode with superior mechanical as well as electrical properties still face a lot of challenges. In present work, melamine foam/polypyrrole (MF/PPy) electrode with high deformation-tolerance and excellent electrochemical performance is prepared by in-situ interfacial polymerization of polypyrrole on commercial melamine foam, where PPy nanoparticles with size of 700 nm are uniformly anchored on the MF skeletons. The electrochemical characterizations show that the electrode exhibits excellent specific area capacitance of 2.685 F cm−2 at 2 mA cm−2 and good cyclic stability with more than 80% of capacitance remained after 3000 cycles. Furthermore, a symmetrical aqueous supercapacitor is assembled and exhibits an excellent energy density up to 75.95 μWh cm−2 at the power density of 5.82 mW cm−2 and excellent cycling stability as the current density increases by 10 times. Even under a high strain of 70%, about 95.76% of the initial capacitance is retained after 500 consecutive compressions. These outstanding performances enable the MF/PPy composite a promising candidate for potential applications in compressible and flexible electrochemical energy storage devices.

To achieve high catalytic activity and stability with low noble-metal loadings on green and natural supports has attracted tremendous attention in the past few years. Herein, a facile strategy is exploited to synthesize Au nanoclusters (with size of ∼1.4 nm) which are homogeneously distributed on carbonized natural lotus leaf sheets with less mass. Compared to the pure AuNCs, the AuNCs@carbonized lotus leaf (AuNCs@C-lotus leaf) micro/nanohybrid with the unique papillae structures and large surface area not only exhibits better catalytic activity for the reduction of 4-nitrophenol (4-NP), but also prevent the aggregation of AuNCs. In addition, the catalytic performance of AuNCs@C-lotus leaf catalyst increased with the temperature increasing of the reaction temperature. Moreover, the AuNCs@C-lotus leaf catalyst can be packed into a filtering platform to fabricate a fixed-bed system, with which the catalytic conversion could reach 71.7% for 0.2 mM 4-NP solution that pass through at flow rate of 1 mL/min. Furthermore, the AuNCs@C-lotus leaf catalyst shows excellent recyclability and only slight loss of catalytical activity is observed after recycling for five successive times. This mild and environmental friendly methodology could be generalized to the synthesis of other metallic nanoparticles@carbonized botanical leaf micro/nanohybrids as promising heterogeneous catalysts for varied catalytic reactions.

Recently, ternary cobalt nickel sulfide, performing as the promising electrode material for supercapacitors has obtained great interests. Herein, the hollow and spinous NiCo2S4 nanotubes are designed and prepared through a simple hydrothermal reaction using the natural silk as the template. The spinous Ni-Co precursors are grown on the natural silk through a facile hydrothermal strategy and the hollow structure is obtained by decomposing the silk via hydrothermal sulfurization. After the calcination treatment, the hollow and spinous NiCo2S4 nanotubes are applied as the electrode material and exhibit better electrochemical performance than the solely vulcanized samples. In addition, owing to the unique hollow and spinous structure of NiCo2S4 nanotubes, the supercapacitor electrode material shows good specific capacitance (630 F g−1 at 1 A g−1), low internal resistance Rs (0.68 Ω) and high capacitance retention (91% after 3000 cycles) at 10 A g−1. Furthermore, an all-solid-state asymmetric supercapacitor is self-assembled with the SC400 composite and exhibits an energy density of 52.34 Wh kg−1 at the power density of 2206.37 W kg−1. Additionally, a blue LED indicator can be powered by connecting two ASCs in series. The prepared hollow and spinous NiCo2S4 nanotubes with excellent electrochemical properties can envision promising applications in energy storage devices and nanotechnology.

Here, two-dimensional (2D) C/TiO2 hybrids synthesized via oxidation of Ti3C2Tx MXenes are reported as an ideal electrorheological (ER) candidate in pursuit of high ER efficiency. The lamellar struc...

NiCo-layered double hydroxide (LDH) has attracted increasing attention in recent years for application in supercapacitors (SCs) owing to its high redox activity and intercalating capability. However, the pristine NiCo-LDH is unable to reach theoretical specific capacitance and satisfying rate capability due to the limited electroactive species and a low ion diffusion rate. Here, we demonstrate novel vertically aligned nanosheet arrays of cobalt metal-organic framework (Co-MOF)@CoNiO

Layered double hydroxides (LDHs) are a kind of classic pseudocapacitive materials with lamellar structure and large specific surface area, which have attracted swinging attention in the electrochemical energy storage area. The CoS

To improve cancer therapeutic efficacy and avoid side effects on normal tissues, a targeted chemo-photothermal nanoplatform was designed based on transferrin-decorated and MoS

The clinical applications of a large variety of inorganic nanomaterials have been severely limited by their long-term retention with potential toxicity in the body. Herein, we develop a self-guided photothermal nanocarrier based on MoS2 nanodots (MoS2 NDs) modified with copolymer P(OEGA-co-VBA) and targeting ligands of transferrin (Tf). The copolymer P(OEGA-co-VBA) is synthesized via RAFT polymerization and not only utilized to improve the biocompatibility of MoS2 NDs, but also efficiently load the drug doxorubicin (DOX) via acid-cleavable Schiff base bonds. Besides, thiol functionalized transferrin (Tf-SH) is anchored onto the surface of MoS2 NDs via the formation of disulfide bonds, which could further enhance the cellular engulfed of MoS2 NDs nanocarrier to HepG2 cells. The as-prepared nanocarrier is stable in physiological condition while quickly release drug upon the synergistic trigger of acidic pH and glutathione (GSH). Moreover, the modified MoS2 (DOX-POV-MoS2-Tf) nanoagents shows better therapeutic effect probably attributed to the synergistic effects of targeted uptake, pH, GSH and NIR induced localized heating, which suggest the designed MoS2 nanocarrier is promising for applications in multi-modal biomedical therapy.

Discovering the relationship of structure and rheological behaviors remains challenging. In this study, the TiO2 nanoparticle decorated magnetic MoS2 nanosheets (Fe3O4@MoS2@TiO2 nanoparticles) exhibited unique rheological behaviors under external electric and magnetic fields owing to their special hierarchical structures. The constructed core–shell structures of the Fe3O4@MoS2@TiO2 nanoparticles were confirmed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The magnetic behaviors were studied using a vibrating sample magnetometer (VSM). The Fe3O4@MoS2@TiO2 nanoparticles exhibited both electrorheological (ER) and magnetorheological (MR) properties that result from the decoration of high dielectric TiO2 nanoparticles on the MoS2 shell and paramagnetic behavior of Fe3O4 nanoparticles in the core, respectively. The MoS2 nanosheets act as superb lubricant at a high shear rate due to their weak interlayer van der Waals forces. The abrupt decrease of shear stress at a critical shear rate was observed under the external magnetic field and the proposed mechanism was also discussed. The unique rheological behaviors of the Fe3O4@MoS2@TiO2 nanoparticle based suspensions highlight the great promise of MoS2-based materials for cornerstone applications in rheological fields.

In this work, the MgCo2O4@α-Co(OH)2 core–shell structure (MgCo2O4@α-Co(OH)2/NF) on foam nickel was prepared using hydrothermal annealing and chemical bath deposition processes to form a supercapacitor positive electrode. MgCo2O4@α-Co(OH)2/NF-2 composite material, with a deposition time of 20 min in a chemical bath, showed a specific capacitance of 1634.8 F g−1 at 1 A g−1, a long cycle stability of 89.4% (in 10,000 cycles) and a rate performance of 78.29%, with excellent electrochemical impedance performance (Rs ≈ 0.507 Ω). The MgCo2O4@α-Co(OH)2/NF-2//AC asymmetric supercapacitors (ASCs) showed a specific capacitance of 185.46 F g−1 at 1 A g−1, with a good long-cycle stability of 91.7% preservation rate after 10,000 cycles. At a power density of 773.19 W kg−1, the energy density is high (65.94 Wh kg−1). We demonstrated that three prepared ASCs devices can produce a diode with a rated voltage of 3 V that continues to emit light for 10 min. This study shows that the MgCo2O4@α-Co(OH)2/NF-2 electrode can be used as a positive electrode for high-efficiency energy storage devices.

Glucose oxidase (GOx), traditionally regarded as an oxidoreductase with high β-D-glucose specificity, has been widely applied as sensing probe for β-D-glucose detection. However, it is found that the specificity of GOx is not absolute and GOx cannot decern β-D-glucose among its isomers such as xylose, mannose and galactose. The existence of the other monosaccharides in sensing system could compromise the sensitivity for β-D-glucose, therefore, it is of great urgency to achieve the highly specific catalytic performance of GOx. Herein, porous metal-organic frameworks (MOF) are prepared as the host matrix for immobilization of both GOx and bovine hemoglobin (BHb), obtained a cascaded catalytic system (MOF@GOx@BHb) with both enhanced GOx activity and peroxidase-like activity owing to the spatially confined effect. Then, using β-D-glucose as both template molecules and substances, hydroxyl radicals are produced continuously and applied for initiating the polymerization of molecular imprinting polymers (MIPs) on the surface of MOF@GOx@BHb. Impressively, the obtaining molecularly imprinted GOx (noted as MOF@GOx@BHb-MIPs) achieves the highly sensitive and specific detection of β-D-glucose in the concentration range of 0.5–20 μM with the LOD = 0.4 μM (S/N = 3) by colorimetry. Similarly, MOF@GOx@BHb-MIPs are subsequently obtained using mannose, xylose and galactose as template molecules, respectively, and also show satisfied specific catalytic activity towards corresponding templates, indicating the effectiveness of the proposed strategy to achieve highly specific catalytic performance of GOx.

Novel nanomaterials and advanced nanotechnologies continue to promote the fast development of new approaches for efficient tumor therapy. As an alternative choice to various traditional therapies, non-invasive photothermal therapy (PTT) has attracted significant attention mainly due to its low cost, highly localizing, specific tumor treatment and minimal side effects on healthy tissues. PTT induced by photo-absorbing agents which can absorb and convert the external NIR laser into heat to ablate tumors. Plenty of studies have shown the significant potential of PTT to treat tumors in future practical applications. However, PTT alone usually could not eradicate tumors considering the intensity of laser gradual attenuates in biological tissues and the heat generated tends to distribute inhomogeneous within tumors tissues. Combination of chemotherapy with photothermal therapy into one system for tumor therapy is an effective strategy to further improve the therapy efficiency. In this Minireview, we focus on the recent advances in constructing PTT therapeutic and multi-model combination therapeutic via integrating nanomaterials and functional polymers.

Molybdenum disulfide (MoS2 ) nanosheets have attracted significant attention due to their photothermal properties, but the poor solubility and colloidal stability limited their further application in biomedical field. Here, we report a targeted photothermal controllable nanocarrier consisting of MoS2 nanosheets modified with block copolymer P(OEG-A)-b-P(VBA-co-KH570) and targeting ligand transferrin. P(OEG-A)-b-P(VBA-co-KH570) is synthesized by RAFT polymerization and utilized not only to improve the solubility of MoS2 nanosheets but also efficiently load the anti-cancer drug doxorubicin (DOX) through an acid-cleavable Schiff base linker. Thiol-functionalized transferrin (Tf-SH) is anchored onto the surface of MoS2 nanosheets by the formation of disulfide bonds, which could further enhance the cellular uptake of DOX and MoS2 to HepG2 cells for high-efficiency synergetic therapy. The drug release experiments exhibited the minimal release of DOX at room temperature and neutral pH, and the maximal drug release of 53 % at acidic tumor pH and hyperthermia condition after 48 h. In addition, the DOX-loaded, Tf-SH and P(OEG-A)-b-P(VBA-co-KH570) modified MoS2 (DOX-POVK-MoS2 -Tf) showed better a therapeutic effect than DOX-POVK-MoS2 and POVK-MoS2 , probably owing to the combined effects of target-directed uptake, acid-triggered drug release, and NIR induced localized heating, which suggest the designed MoS2 nanocarriers are promising for applications in multi-modal cancer therapy.

Near-infrared (NIR) light possesses great advantages for light-responsive controllable drug release, such as deep tissue penetration and low damage to healthy tissues. Herein, a targeted and NIR-triggered drug delivery system is developed based on a NIR dye, indocyanine green (ICG), and anticancer drug, doxorubicin hydrochloride (DOX)-loaded thermo-responsive block copolymer capsule, in which the drug release can be controlled via NIR irradiation and folic acid (FA) molecule endows the drug carrier with the ability of targeted receptor-mediated endocytosis. After co-encapsulation of DOX and ICG, the capsule carrier exhibited wider NIR absorption peak and the loaded DOX was released rapidly from the capsules upon irradiation by NIR laser (808 nm). In addition, the results demonstrated that the FA modified capsule carrier exhibited the higher cytotoxicity to HeLa cells with NIR irradiation compared with other treatments, indicating the efficient chemo-photothermal targeted therapy.

To improve cancer therapeutic efficacy and avoid side effects on normal tissues, a targeted chemo–photothermal nanoplatform was designed based on transferrin-decorated and MoS2-capped hollow mesoporous silica nanospheres. MoS2 nanosheets acted as a gatekeeper to prevent the leakage of DOX from the drug delivery system as well as the photothermal agent (PTA) to improve the therapeutic effect and facilitate the NIR-triggered endosomal escape. In this work, MoS2 nanosheets were anchored on the surface of hollow mesoporous silica nanospheres (HMSNs) via the formation of disulfide bonds (–S–S), which could be easily cleaved in the presence of the intracellular GSH, leading to stimuli-responsive drug release from the hollow mesoporous silica nanocarriers. Moreover, to further improve the tumor specificity and cellular uptake of the anti-cancer drug, the nanocarrier surface was also modified with the targeting ligand transferrin via –S–S linkage. The results demonstrated that the transferrin-decorated, MoS2-capped HMSNs can be utilized as a targeting chemo–photothermal synergetic system with high therapeutic efficacy.

The development for environmentally friendly energy conversion and storage equipment has given rise to tremendous research efforts as a result of the growing requirements for environmental friendly resources and the rapid consumption of traditional fossil fuel. Herein, a novel hierarchical CoO/NiO-Cu@CuO heterostructure is successfully devised and synthesized. Cobalt/nickel ions are used to generate novel CoO/NiO-doped laminated CuO nanospheres through the facile in situ wet oxidation combined with cation exchange and calcination strategies. As a result, the electrochemical supercapacitance of the as-prepared CoO/NiO-Cu@CuO electrode can reach 875 C cm

Supercapacitors have attracted tremendous research interest, since they are expected to achieve battery-level energy density, while having a long calendar life and short charging time. Herein, a novel asymmetric supercapacitor has been successfully assembled from NiCo

Freestanding electrodes fabricated with hierarchical core-shell micro-/nano-structured materials synthesized from redox-type metal oxides show enormous potential for portable electronic devices. In this, a novel and facile strategy for the preparation of petaloid and origami-lantern shaped MnO2/Co2CH@C hierarchical porous core-shell nanorod arrays is proposed. The fabricated electrode based on MnO2/Co2CH@C hybrid composite exhibits superior capability of 2022 mF cm−2 under high current density of 5 mA cm−2, which can be explained by the well-oriented petal-like and origami-lantern shaped nanosheets as well as the 3D core-shell porous hierarchical structure. Additionally, a solid-state asymmetric supercapacitor equipment is assembled on basis of the synthesized hierarchical MnO2/Co2CH@C hybrid, exhibiting an energy density of 15 Wh kg−1 at the power density of 255 W kg−1. Notably, the multifunctional instrument can be operated by the assembled device for 8 min, while monitoring time, temperature and air humidity in a portable outdoor environment. Moreover, a blue indicator can also be operated for 9 min long, evidencing their potential commercial applications. Overall, this work demonstrates the promising potential of the synthesized novel origami-lantern shaped and highly oriented hierarchical composites for electrochemical energy storage applications.

Recently, elemental doping has proven to be an efficient method to improve the electrochemical performance of nanomaterials. In this work, we successfully synthesized Ni1-xCoxMoO4 with tunable morphologies through Co-doping by a facile chemical co-precipitation method, among which Ni0.85Co0.15MoO4 displays an excellent specific capacitance (1301 F g−1 at 1 A g−1), which is higher than NiMoO4 electrode (1050.4 F g−1 at 1 A g−1) and Ni0.7Co0.3MoO4 electrode (755.2 F g−1 at 1 A g−1). In addition, Ni0.85Co0.15MoO4 electrode shows excellent cycling stability with 86% retention of its original capacitance after 3000 cycles. Additionally, an asymmetric supercapacitor (ASC) device can be fabricated using Ni0.85Co0.15MoO4/nickel foam (Ni0.85Co0.15MoO4/NF) as positive electrode and active carbon/nickel foam (AC/NF) as negative electrode. The as-fabricated ASC achieves a high energy density of 37.26 Wh kg−1 at the power density of 400 W kg−1, highlighting its potential application for the efficient energy storage devices.

Mesoporous carbon nanoparticles (MCNs) were prepared through a series of annealing procedures using well-controlled diblock copolymer micelles as precursors. The micelles were prepared from poly(acrylonitrile)-block-poly(methylmethacrylate) (PAN-b-PMMA), and synthesized via reversible addition–fragmentation chain transfer (RAFT) polymerization. The RAFT-controlled synthesis of block copolymer, PAN-b-PMMA was conducted either in solution or emulsion conditions. It was found that micelles with well-defined morphology could be directly formed from the emulsion polymerization. The as-synthesized micelles containing hydrophilic PAN corona as the carbon source and hydrophobic PMMA core as the sacrificing template underwent a microphase-separation process to form a nanostructure at 250 °C, followed by carbonization at 800 °C to afford MCNs. What's more, the MCNs based supercapacitor exhibited a good capacitance value of 220 F g−1 and an excellent cycling performance of 91% capacitance retention after 10000 cycles. The as-prepared MCNs are envisioned to provide broad practical applications in the fields of energy storage and nanotechnology.

Nanostructured carbon materials have shown promising applications for energy storage because of their high capacitive characteristic. However, developing three-dimensional (3D) hierarchical carbon materials with both high compressibility and capacitance is still challenging. Herein, we report the fabrication of hierarchical polypyrrole (PPy)/graphene (reduced graphene oxide (G) and holey reduced graphene oxide (h-G))/melamine composite foam through a simple template method. By systematically optimizing the mass ratios of the G/h-G and the sizes of the PPy nanoparticles (PPy NPs), the as-prepared composite electrode displays a gravimetric capacitance of 422.6 F g−1 at a current density of 0.5 A g−1. Due to the interconnected h-G/G network and elastic melamine foam (MF) skeleton, the as-prepared composite electrode also shows compressible performance, which can be compressed to a strain of 60% and completely recover to its original shape when released. When the composite electrodes are assembled to a compressible supercapacitor which shows a stable capacitance under different compressive strains (0%, 25%, 50% and 75%) and a long-term compression test at 50% strain for 100 cycles. Therefore, the successful preparation of compressible composite electrode should open many opportunities in compressible and durable energy storage devices.

Supercapacitors are attracting tremendous research interest because they are expected to achieve battery-level energy density while having long calendar life and short charging time. Ultrathin layered double hydroxide nanosheets (LDHs) are promising candidates as electrode materials for energy storage. Herein, we have successfully designed and synthesized a hierarchical NiMn-LDH@CuO/CF core-shell heterostructure which comprises a vertical and intercrossing ultrathin NiMn-LDHs nanosheets shell and a slightly curly and tops tangled CuO nanowires core. The synthesized NiMn-LDH@CuO/CF electrode exhibits a high areal capacitance of 6077 mF cm−2 (2430.8 F g−1) at a current density of 2 mA cm−2 (0.8 A g−1), which is significant higher than those of CF, Cu(OH)2/CF, CuO/CF, NiMn-LDH/CF and NiMn-LDH electrodes. Moreover, a superior cycling stability of 89.22% retention after 8000 cycles at a high current density of 50 mA cm−2 is observed and a low internal resistance Rs (0.584 Ω) can be achieved. Furthermore, an all solid-state asymmetric supercapacitor (ASC) device based on the as-synthesized hierarchical NiMn-LDH@CuO/CF core-shell heterostructure hybrid material as positive electrode and activated carbon as negative electrode is successfully fabricated and exhibits an energy density of 10.8 W h kg−1 at a power density of 100 W kg−1. Additionally, a LED indicator can be lit up for eight minutes when three ASCs are connected in series. The excellent electrochemical performances can be credited to the significant enhancement of the specific surface area, charge transport and mechanical stability resulted from the ultrathin LDH shell, the highly conductive CuO nanowires core-shell nanostructure. This strategy for the fabrication of hierarchical core-shell heterostructure could have enormous potential for applications in high performance energy storage devices.