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PolyI:C is an immunomodulatory agent that can be used in immunotherapy, but its transportation in the body is hindered. In this study, a chitosan (CS)-graft-polyethyleneimine (PEI) copolymer (C-g-P) is prepared by an N,N′-carbonyl diimidazole (CDI) coupling method as a drug carrier for PolyI:C and simulated antigen ovalbumin (OVA). The results of FT-IR, 1H NMR, elemental analysis and cytotoxicity studies show that PEI is successfully grafted onto CS, and a low cytotoxicity of C-g-P-x (x = 1, 2, 3) with different PEI grafting rates are obtained. C-g-P-x-PolyI:C/OVA (C-g-P-x-PO) (x = 1, 2, 3) nanoparticles are prepared by combining C-g-P-x (x = 1, 2, 3), PolyI:C and OVA by electrostatic self-assembly. The results of agarose gel electrophoresis show that PolyI:C is well coated by the graft copolymer and protected from nuclease degradation. The results show that C-g-P-1-PO nanoparticles with graft copolymer to PolyI:C (N/P) ratios of 80:1 have the best solution stability, and the OVA encapsulation efficiency is 60.6%. The nanoparticles also have a suitable size and regular shape to be absorbed by cells. In vitro immunoassay results show that PolyI:C and OVA-loaded nanoparticles promote the secretion of tumor necrosis factor α (TNF-α) and interferon γ (IFN-γ). CS-g-PEI is a reliable drug carrier for the delivery of PolyI:C and OVA, and it also provides the possibility to carry other drugs.

The stabilization of emulsion depends on the combination adsorption of surfactant-modified nanoparticles and surfactants on the oil-water interface.

NGNS-PP could improve the diffusion of Li+ effectively and inhibit the growth of dendrites. The Li//Li cell with NGNS-PP separator exhibited excellent cycling stability (12 000 h at 6 mA cm−2).

A bimetallic MoNi/WNi nanoalloy is used to fabricate an ultra-sensitive temperature sensor with a high constant of thermistor B (10 890 K near room temperature) capable of dynamic respiratory monitoring and operating under high humidity (>95%) conditions.

β-Nucleosides and their analogs are dominant clinically-used antiviral and antitumor drugs. α-Nucleosides, the anomers of β-nucleosides, exist in nature and have significant potential as drugs or drug carriers. Currently, the most widely used methods for synthesizing β- and α-nucleosides are via N-glycosylation and pentose aminooxazoline, respectively. However, the stereoselectivities of both methods highly depend on the assisting group at the C2’ position. Herein, we report an additive-controlled stereodivergent iodocyclization method for the selective synthesis of α- or β-nucleosides. The stereoselectivity at the anomeric carbon is controlled by the additive (NaI for β-nucleosides; PPh3S for α-nucleosides). A series of β- and α-nucleosides are prepared in high yields (up to 95%) and stereoselectivities (β:α up to 66:1, α:β up to 70:1). Notably, the introduced iodine at the C2’ position of the nucleoside is readily functionalized, leading to multiple structurally diverse nucleoside analogs, including stavudine, an FDA-approved anti-HIV agent, and molnupiravir, an FDA-approved anti-SARS-CoV-2 agent.

Sodium-ion batteries (SIBs) have drawn much attention due to the abundance and low cost of sodium. However, electrode materials of SIBs displayed sluggish Na+ diffusivity and fatal volume expansion, owing to the larger ionic radius of Na+ ions than Li+ ions. In this work, we built the CoSe2 nanoparticles embedded in graphene nanoscrolls (GNS) as advanced anodes for high-rate SIBs. The CoSe2/C@GNS anodes exhibited a high reversible capacity of 545 mA h g−1 at 0.2 A g−1. Moreover, they showed an outstanding cycling stability of 455 mA h g−1 after 5000 cycles at 1 A g−1, with a capacity retention of 92% calculated from 10th cycle. The CoSe2/C@GNS anode also demonstrate ultrahigh rate capabilities (212.5 mAh g−1 at 50 A g−1). In addition, with a high mass loading (6 mg cm−2), the electrode still displayed a stable capacity (412 mA h g−1 1 A g−1). The fast electron transfer and Na+ ion diffusion kinetics creates the excellent electrochemical properties, on account of the uniform arrangement of nanoparticles and unique reticular crosslinking structure of CoSe2/C@GNS. This strategy could also be constructed other electrode materials, which provides more probabilities for the development of SIBs.

Core-shell silver nanoparticles@mesoporous silica spherical nanoparticles (Ag NPs@MSNs) were prepared by a two-step method. First, Ag NPs were synthesized by chemical reduction using silver nitrate (AgNO₃) as the precursor, cetyl trimethyl ammonium bromide (CTAB) as the stabilizer, and sodium borohydride (NaBH₄) as the reductant. Then, MSNs were obtained by employing CTABstabilized Ag NPs as the template and hydrolyzing tetraethoxysilane (TEOS) precursor in the presence of the alkaline precipitant, triethanolamine (TEOA). The effects of different preparation routes (core-first vs. shell-first), type of reductants as well as extraction methods and agents were studied. The obtained core-shell NPs were characterized by infrared spectroscopy (IR) and transmission electron microscopy (TEM). Our results showed that the core-first route was viable to produce uniform Ag NPs@MSNs with ordered mesostructures. Afterwards, those NPs were used as the catalyst to catalyze the reduction of rhodamine, a model dye compound representing organic pollutants in waste water, in the presence of NaBH₄. It was found that Ag NPs@MSNs not only were efficient catalysts but also participated as coreductants in the reaction. Moreover, they exhibited almost no loss of catalytic efficacy after several reduction cycles, which indicated their promising future use as efficient recyclable catalysts for organic pollutant treatments.

Lithium vanadium phosphate Li3V2(PO4)3 (LVP)-based cathodes have attracted much attention in pursuit of high-performance lithium-ion batteries (LIBs). In this study, an ionic liquid (IL) has been introduced into the electrospinning process for the first time, successfully leading to the formation of free-standing cathodes built up of LVP nanocubes embedded in N-doped carbon nanofibers (LVP-NC/NCNF). In particular, the IL plays multiple roles in the resulting free-standing cathodes: (i) the IL improves the feasibility of the PAN-based electrospinning system for preparing electrode materials due to its good solubility, resulting in a self-supporting substrate conductive network with good mechanical properties and electrical conductivity; (ii) the IL can act as a structure-directing agent to induce the formation of (100) facet-oriented LVP nanocubes, giving rise to a convenient lithium-ion transport path; and (iii) the IL adsorbed on the surface of LVP nanocubes can form a N-doped dual-phase carbon coating layer during the heat-treatment process, further enhancing the electronic conductivity of the entire electrode. As a result, LVP-NC/NCNF free-standing electrodes exhibit an outstanding electrochemical performance including a high specific capacity, stable cycling performance and superior rate capability. Specially, the LVP-NC/NCNF free-standing cathodes deliver a high discharge capacity of 143.6 mA h g−1 at 5C for a prolonged cycling life of over 1000 cycles. It is highly expected that this facile IL-assisted electrospinning method can be expanded to other polyanion-based cathodes, thus presenting new opportunities for the design and fabrication of high-performance free-standing electrodes for LIBs.

Flexible lithium ion batteries are important for wearable electronic devices. Herein, 1T/2H phase MoS2 nanosheets are grown on carbon fiber cloth, and the ultra-small SnS2 nanoparticles are anchored in the surface of MoS2 nanosheets uniformly. We fabricate the hierarchical nanostructures via a hydrothermal method then water bath process. During in-situ growth of 1T/2H phase MoS2, urea is used as the surfactant and NH4+ (produced by urea and ammonium molybdate tetrahydrate) is acted as insertion guest ions to stabilize 1T phase MoS2. The synergistic effects between MoS2 nanosheets and SnS2 nanoparticles can improve structural stability of the electrode and significant enhance the transport of Li ions and electrons, thereby ameliorate the electrochemical properties. When applied as a binder-free, flexible Li-ion battery anode, it exhibits admirable cycling stability and excellent rate performance. Due to the presence of 1T phase MoS2 and uniform distribution of ultra-small SnS2 nanoparticles on MoS2 nanosheets, the SnS2/MoS2/carbon fiber cloth composites maintain 1294 mA h g−1 when cycling at 100 mA g−1 after 120 cycles. A highly flexible battery based on SnS2/MoS2/carbon fiber cloth and LiCoO2 is fabricated, demonstrating excellent mechanical flexibility and cycling stability.

Motivated by the success of using graphene oxide (GO) as a nanofiller of composites, there is a drive to search for this new kind of carbon material as a reinforcing phase in biocomposites. In the present work, graphene oxide and chitosan (CS) functionalized graphene oxide were introduced as templates to fabricate hydroxyapatite (HA) using a facile solution-based in situ synthesis method, and GO–HA and CS-GO–HA nanocomposites were successfully prepared for the first time. It was found that the spindle like HA nanoparticles with a diameter of about 27 ± 7 nm and a length around 150 ± 25 nm were decorated randomly and strongly on the surface or aggregated at the edges of the pristine and chitosan functionalized GO matrix. Compared with HA, the prepared GO-based HA nanocomposites displayed an increased elastic modulus and hardness. The in vitro cytotoxicity of the prepared nanocomposites was investigated using CCK-8 assay on murine fibroblast L-929 cell line and human osteoblast-like MG-63 cell line, respectively. Both of the nanocomposites exhibited a high cell proliferation rate for L-929 and MG-63, and the CS-GO–HA could provide significantly higher cell viability and alkaline phosphatase activity compared to the GO–HA composite. These findings may provide new prospects for utilizing the GO-based hydroxyapatite biocomposites in bone repair, bone augmentation, as well as coating of biomedical implants and broaden the application of GO sheets in biological areas.

Herein, we report a novel structure with hollow CoSn alloy nanoboxes encapsulated in N-doped carbon nanotubes (CoSn@N-C nanotubes) for Li-ion batteries (LIBs) and K-ion batteries (PIBs). The structure is synthesized by an electrospinning method and subsequent calcination process. The obtained hollow N-doped carbon nanotubes not only effectively ensure the stability of CoSn alloys, but also accelerate ionic/electronic transport rate. Besides, the inner inactive Co and the hollow structure of CoSn nanoboxes can buffer the volume expansion of CoSn alloys during cycling. Benefiting from the hierarchical nanostructure and synergistic effect of the components, the electrodes demonstrate a reversible capacity of 653 mAh g−1 after 450 cycles in LIBs at 0.2 A g−1. Notably in PIBs, the CoSn@N-C nanotubes exhibits high rate capabilities up to 10 A g−1 and remarkable cycling life (178 mAh g−1 after 2000 cycles at 0.5 A g−1).

Ovalbumin (OVA) is a globular protein found in hen's eggs that has excellent nutritional and functional properties but is a major allergen. Previous studies have shown that ultrasound pretreatment combined with glycation (sonication-glycation) of OVA markedly reduced its IgG and IgE binding capacities and enhanced its antioxidant activity. In this study, the effects of sonication-glycation on a number of important functional attributes of OVA were studied: foaming, emulsifying, and digestibility. These processes significantly enhanced the foaming and emulsifying properties of OVA by increasing the exposure of hydrophobic residues at the protein surfaces. Moreover, reversed-phase chromatography indicated that sonication-glycation only caused a small decrease in OVA digestibility under simulated gastric and small intestine conditions, and that the level of IgG and IgE binding of OVA was exceedingly low after digestion. Furthermore, sonication promoted the glycation of OVA by increasing the number of exposed glycation sites, as determined by high-resolution mass spectrometry. These results imply that sonication-glycation is a promising method for improving the functional performance of food proteins, while also reducing their immunogenicity.

Reprogramming has been shown to involve EMT–MET; however, its role in cell differentiation is unclear. We report here that in vitro differentiation of hESCs to hepatic lineage undergoes a sequential EMT–MET with an obligatory intermediate mesenchymal phase. Gene expression analysis reveals that Activin A-induced formation of definitive endoderm (DE) accompanies a synchronous EMT mediated by autocrine TGFβ signalling followed by a MET process. Pharmacological inhibition of TGFβ signalling blocks the EMT as well as DE formation. We then identify SNAI1 as the key EMT transcriptional factor required for the specification of DE. Genetic ablation of SNAI1 in hESCs does not affect the maintenance of pluripotency or neural differentiation, but completely disrupts the formation of DE. These results reveal a critical mesenchymal phase during the acquisition of DE, highlighting a role for sequential EMT–METs in both differentiation and reprogramming., Reprogramming has been shown to involve EMT-MET; however, its role in cell differentiation is unclear. Here the authors show that during in vitro differentiation of hepatocytes, Activin A-induced formation of definitive endoderm requires EMT mediated by TGFβ signalling, followed by a MET process.

Silver nanoparticles (Ag NPs) of improved thermal stability against long-term aggregation were prepared using the polystyrene-b-poly(4-vinylpyridine)-b-polystyrene (PS-b-P4VP-b-PS) triblock copolymer as a multidentate ligand. First, PS-b-P4VP-b-PS was synthesized by sequential reversible addition–fragmentation transfer (RAFT) polymerization of styrene and 4-vinylpydine using a trithiocarbonate chain transfer agent (CTA). Then Ag NPs were obtained by in situ reduction of silver nitrate using PS-b-P4VP-b-PS as a multidentate ligand. The obtained Ag NPs were stable in solution for at least 24 h while being heated at 110°C. The effect of the molar ratio of N atoms of the P4VP chain segment and AgNO3 on the stability of Ag NPs was studied, and the results suggested that Ag NPs were very stable even if the molar ratio of N atoms of the P4VP chain segment and AgNO3 was very low. This method is promising to scale up the preparation of metal NPs with good dispersibility and thermal stability, which still remains challenging. To further improve its thermal stability, 1,4-dibromobutane was used to chemically crosslink the P4VP chain segment in solution. However, the results proved that the crosslink method is infeasible to further improve the thermal stability of Ag NPs in this system.

Metal–organic frameworks (MOFs) have attracted considerable attention for their important applications. Recently, significant efforts have been devoted to constructing hollow MOF structures and integrating MOFs with other functional materials to further enhance the inherent performance and endow them with new functions. However, it still remains a big challenge to synthesize well-defined MOF composites and MOF hollow structures, especially those with structural and compositional complexity. In this work, we demonstrate a chemical transformation method to synthesize unique MOF composites, as well as hollow and complex hollow MOF structures. This method could intelligently overcome the difficulty that is caused by the possible lattice mismatch between MOFs and other functional materials. Impressively, a series of unique MOF@MOF core–shell structures, MOF composites, MOF hollow and complex hollow structures are successfully synthesized. Moreover, porous mixed metal oxide hollow and complex structures are obtained by annealing the corresponding MOF hollow and complex hollow structures in air. We anticipate that these unique MOF composites, hollow structures and the derived porous mixed metal oxide hollow structures could find promising applications in many other fields. As an example, NiFe oxide cube-in-box complex hollow nanostructures are evaluated as anode materials for lithium-ion batteries (LIBs), which exhibit enhanced electrochemical performance compared to the simple nanobox counterparts.

V2O5-decorated α-Fe2O3 composite nanorods were synthesized successfully by electrospinning and an environmentally-friendly soak-calcination method. The composite showed high selectivity and stability to diethylamine gas as well as ultra fast response times within 2 s to 100 ppm diethylamine gas.

CuO mesocrystals have been synthesized by nonclassical crystallization in the presence of an ionic liquid and n-butylamine under hydrothermal conditions. The resultant mesocrystals are composed of anisotropic nanosheets and nanorods as building blocks and possess distinct 3D hierarchical superstructure exposed {001} crystal planes. The mechanisms underlying the sequential formation of the mesocrystals are as follows: amorphous particles first appeared under a high degree of supersaturation according to the Ostwald rule of stages; then, nanosheet subunits were favored to form due to the protection of the {001} planes by n-butylamine molecules and etching of the {010} planes by a hydrolysis reaction, leading to the formation of a large number of dangling bonds in the {010} planes. Therefore, the ionic liquid can interact with these primary particles to facilitate a self-assembled superstructure by π–π interactions along the [010] direction due to the highly ionic nature, resulting in a 3D framework structure of primary particles composed of nanosheet and nanorod subunits by oriented attachment. Moreover, owing to the inherent porosity associated with well-defined nanoparticle orientation, the 3D hierarchical CuO mesocrystals achieved a higher electrochemical property as anodes for Li-ion batteries, surpassing the performance of CuO nanosheets and CuO nanorods. The unique characteristics of the hierarchical mesostalline electrodes show an ideal geometry to form a stable SEI film, which offers a facile route for designing high-performance electrodes for long-life Li-ion batteries.

Ionic self-assembly, the combination of the building blocks with opposite charge by electrostatic association, has many merits, such as simple, cheap and easy to get, flexible reversible and wide range of applications. In this paper, fibres were synthesized by combining surfactant N, N-dimethylferrocenylmethyl hexadecyl-ammonium bromide (Fc16AB) and fluorescent dye methyl orange (MO) using ionic self-assembly techniques. The morphology of self-assemblies with different concentration are measured and characterized by optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that the concentration of Fc16AB and MO has great effects on the morphology of obtained microfibers.

NiMoO4@Co(OH)2 core/shell structure nanowire arrays (NWAs) supported on Ni foam were successfully fabricated via a facile hydrothermal growth and electrochemical deposition route, and applied in supercapacitors (SCs). The smart combination of Co(OH)2 and NiMoO4 nanostructures in nanowire arrays exhibited greatly enhanced electrochemical performance. Co(OH)2 nanoflakes were uniformly wrapped on the surface of each NiMoO4 nanowire, which increased the capacitance of NiMoO4 NWAs to a high areal capacitance of 2.335 F cm−2 at 5 mA cm−2 and 0.909 F cm−2 at 50 mA cm−2. The electrode also exhibited good cycling ability; 83% of the initial capacity was retained after 5000 cycles at a current density of 20 mA cm−2. These results indicate that the NiMoO4@Co(OH)2 NWAs could be a promising electrode material for high-performance electrochemical capacitors.

Currently, tremendous efforts have been focused on developing high-performance anode materials for lithium-ion batteries (LIBs). In this work, we develop an effective strategy to synthesize a nanocomposite of ZnMn2O4 porous spheres and graphene (ZMO-G PSs) as an advanced anode material for high-performance LIBs. SEM and TEM characterizations reveal that the ZMO PSs are tightly wrapped by graphene sheets and uniformly distributed within the graphene matrix. Owing to the rational combination of the merits of both ZMO PSs and graphene, the as-prepared ZMO-G PSs nanocomposite exhibits significant enhanced LIB performance with high reversible capacity, long cycle life and good rate performance. Remarkably, the nanocomposite exhibits a high reversible capacity of 926.4 mA h g−1 after 100 cycles at a current density of 200 mA g−1, which is much higher than that of pure ZMO PSs (493.3 mA h g−1). Moreover, a high capacity of 560.8 mA h g−1 can be retained at a high current density of 1200 mA g−1. These electrochemical results suggest the ZMO-G PSs nanocomposite could be a promising anode material in energy storage applications for high-performance LIBs.

Ni(SO4)0.3(OH)1.4 nanobelts (NSOH NBs) and NiO nanoparticles (NPs) were used as the sensitive layers for a surface acoustic wave (SAW) humidity sensor. A high frequency SAW resonator up to 1.54 GHz was fabricated on a lithium niobate substrate as the sensing platform. The SAW sensors based on the NSOH NBs and the NiO NPs exhibited significantly decreased resonant frequencies with enhanced relative humidity (RH) from 11% to 85%, and the frequency response was found to be ¬2.95 MHz and ¬5.81 MHz, respectively. Both sensors showed rapid and reversible responses with excellent repeatability and long-term stability. The response and recovery times for NiO NPs were 23 s and 4 s, respectively. The NiO NP based sensor also showed negligible interference with various gases such as hydrogen and methane, demonstrating good cross-selectivity even while working in the GHz range. The high performance could be ascribed to the enhancement of the resonant frequency and the use of hydrophilic nanomaterials with a high surface-to-volume ratio.

A novel hybrid structure of core/shell NiMoO4@MnO2 was directly synthesized on carbon cloth by a facile two-step hydrothermal route for supercapacitors. The smart combination of NiMoO4 and MnO2 shows a synergistic effect for capacitors with greatly enhanced performance. The NiMoO4@MnO2 electrode yields high-capacitance performance with a high areal capacitance of 3.90 F cm−2 at a charge and discharge current density of 8 mA cm−2 and 3.22 F cm−2 at 24 mA cm−2 with a desirable cycling ability (90.5% of the initial specific capacitance remains after 4000 cycles). Such core/shell hybrid nanoarchitectures exhibit remarkable electrochemical performance with high capacitance and excellent long-term cycling stability, which could be promising pseudocapacitive electrode materials for high-performance supercapacitors.

Hierarchical CoFe2O4/MnO2/C nanotubes were prepared by electrospinning and a subsequent hydrothermal method. Their electrochemical properties were investigated for use as anode materials for lithium-ion batteries. The CoFe2O4/MnO2/C composite displayed a stable cycling performance with a reversible capacity of 713.6 mA h g−1 after 250 discharge–charge cycles at a current density of 100 mA g−1, much higher than that of CoFe2O4/C nanofibers, which displayed a capacity of 200 mA h g−1 after 90 cycles. The improved electrochemical performance could be ascribed to the stable hierarchical structure of the nanocomposite, the existence of carbon, the high active surface area, and the high theoretical capacity of MnO2. Given their enhanced electrochemical performance, the CoFe2O4/MnO2/C heterostructure composite can be considered as a promising anode for lithium-ion batteries.

Gas sensors based on a noble metal–semiconductor are widely used, and they show a positive temperature response to hydrogen below 400 °C. In this study, a catalytically activated hydrogen sensor is obtained based on Pd decorated WO3 nanoplates constructed by a solvothermal method. An insight into the role of Pd catalyst in the outstanding performance is provided by comparing the sensing properties of this sensor with those of a traditional one made from the same pristine WO3. The pure WO3 sensor exhibits poor selectivity and low sensitivity to hydrogen. In contrast, the observed response of the as-produced sensor is up to 843 at a low operating temperature of 80 °C; the response value is even greater than that of WO3 sensors at high temperatures (250–400 °C). In addition, the Pd-loaded WO3 sensors show excellent selectivity towards H2 in comparison to other common gases (CH4, C3H6O, C2H6, C3H8O and NH3). The significantly improved performance is thoroughly explained in terms of the adsorption–desorption mechanism and chemical kinetics theories. Furthermore, an interfacial model demonstrated in this report indicates that the interfacial barrier between WO3 nanoparticles can be a novel effect for excellent gas sensing performance.

A facile and low-cost approach has been developed for the fabrication of large-area nickel sulfide nanosheets via the hydrothermally assisted sulfurization of Ni foam. The obtained Ni3S2 nanosheets exhibit perfect supercapacitor performance, retaining almost 93.6% of the maximum capacitance after 3000 cycles. The strategy of self-sulfurization is promising for use in the construction of other nanoarchitectured sulfide (e.g., CuS, FeS and SnS) arrays for electrochemical applications.

In this paper, ZnFe2O4 nanotubes were fabricated by a simple electrospinning method. The scanning electron microscopy images show that the obtained ZnFe2O4 nanotubes had a hollow structure and had a diameter of about 80–100 nm, and wall thickness of 15–20 nm. A humidity sensor based on as-prepared nanotubes was fabricated and exhibited good performance, high sensitivity, fast response and recovery and good stability. When RH switched between 75% and 35%, the resistance changed from 2.63 × 107 Ω to 1.65 × 109 Ω. The corresponding sensitivity was calculated to be 62.7. The response and recovery time was 11 s and 5.6 s respectively. The sensor also showed good stability and repeatability. These results indicated that the synthesized ZnFe2O4 nanotubes were promising candidates for high-performance humidity sensors.

A novel resistance type humidity sensor was fabricated using poly(ionic liquid)s PEVIm-Br, which not only exhibited high sensitivity at a relative humidity (RH) in the range of 11-98%, but also featured short response and recovery time, as well as small hysteresis and good repeatability, proving poly(ionic liquid)s to be promising sensing materials for high-performance humidity sensors.

In this study, we investigated the nanocomposites composed of graphene, SnOx and carbon fibers (CFs) for humidity sensing applications. The composites were obtained by an electrospinning method followed by addition of graphene. SnOx/CFs uniformly dispersed into graphene nanosheets. SnOx and graphene were proved to be promising sensing materials. The amorphous carbon fibers could supply more channels for transportation of protons or electrons. Therefore, the composites exhibited high humidity sensing performance. The resistance of the sensor increases two times with decreasing relative humidity from 55% to 30%. The sensitivity to humidity increased by almost 100% after adding graphene to SnOx/CF nanocomposites. The response and recovery times were 8 s and 6 s at 30% RH, respectively. The results demonstrated that rational design of nanocomposites with graphene could be a favorable strategy to improve humidity sensing properties.

Flexible mats composed of CoO–graphene–carbon nanofibers have been prepared by electrospinning and a subsequent thermal treatment. The flexible mats of CoO–graphene–carbon annealed at 650 °C exhibited discharge capacities of 760 and 690 mA h g−1 at the 252nd and 352nd cycle, respectively, at a current density of 500 mA g−1, which are much higher than those of pure carbon, graphene–carbon, and CoO–carbon nanofibers at the respective cycles. The CoO–graphene–carbon nanofibers can deliver a discharge capacity of 400 mA h g−1 at a current density of 2 A g−1, which is also higher than the values obtain for CoO–carbon and graphene–carbon nanofibers. The improved electrochemical properties of the flexible CoO–graphene–carbon nanofiber mats could be ascribed to the framework, which allows for fast diffusion of Li+, the presence of graphene, which enhances the conductivity and the mechanical properties of the mats, and the defective sites that arise from the introduced CoO and graphene which can store Li+. It is believed that the electrospinning method used to combine the material with graphene could be a useful approach to prepare flexible mats for lithium-ion batteries, supercapacitors, and fuel cells.

ZnCo2O4 nanowire cluster arrays (NWCAs) were directly grown on Ni foam via a facile hydrothermal method. The resulting products were analyzed by using X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The ZnCo2O4 NWCAs on Ni foam were directly used as integrated electrodes for supercapacitors and exhibited a high specific capacitance of 4.05 F cm−2 at 20 mA cm−2 (1620 F g−1 at 8 A g−1) in 3 M KOH aqueous solution, and an excellent cycling ability at various current densities up to 100 mA cm−2 (40 A g−1); 90% of the initial capacitance remained after 6000 cycles. Moreover, the asymmetric supercapacitor had a high energy density of 41.00 W h kg−1 at a power density of 384 W kg−1 and 16.63 W h kg−1 at a high power density of 2561 W kg−1. Such excellent rate properties and superior cycling life suggest that ZnCo2O4 NWCAs can not only be applied in high energy density fields, but also used in high power density applications.

Three kinds of humidity sensors were fabricated from WO3–SnO2 composite hollow nanospheres (WO3–SnO2 HNS), WO3 nanoparticles (WO3 NPs) and SnO2 nanoparticles (SnO2 NPs). WO3–SnO2 HNS were prepared by a facile hydrothermal process with a diameter and thickness of about 550 nm and 30 nm, respectively. Temperature-dependent properties of as-prepared humidity sensors were investigated at various values of relative humidity and temperature. It was found that the WO3–SnO2 HNS humidity sensor showed good performance at 80 °C. The response time, recovery time and sensitivity were evaluated while switching the humidity between 35% RH and 98% RH. The response time decreased from 289 to 29 s, the recovery time reduced from 22 to 8 s, and the sensitivity changed from 16.2 to 11.4 as the work temperature was raised from 24 to 80 °C. An opposite humidity sensing phenomenon was observed between WO3 NPs and SnO2 NPs at a high temperature, which might explain the temperature-dependent properties of the WO3–SnO2 HNS humidity sensor. This work could stimulate a right approach to design practical humidity sensors with high sensitivity, long stability and fast response.

Co3O4 nanosheet arrays (NSAs) were successfully grown on flexible carbon cloth (CC) by a simple electrochemical deposition method. The deposited films were composed of homogeneous ultrathin hierarchical porous Co3O4 nanosheets. Such Co3O4 NSAs/CC electrodes showed superior electrochemical performance, indicating a promising method to fabricate flexible electrodes for Li-ion batteries.

In this report, ZnWO4 nanowall arrays (NWAs) were grown on Ni foam by a hydrothermal route and investigated for application in supercapacitors for the first time. The resulting NWAs were analyzed by using X-ray diffraction spectroscopy, scanning electron microscopy, and transmission electron microscopy. ZnWO4 NWAs exhibited high electrochemical property with a specific capacitance of 2.5 F cm−2 at a charge and discharge current density of 20 mA cm−2 (1250 F g−1 at current density of 10 A g−1). Furthermore, they showed an excellent cycling ability at different current densities up to 100 mA cm−2, and 92% (2.3 F cm−2) of the initial capacitance remained after 4000 cycles. The open network structure consisting of interconnected ZnWO4 NWAs directly grown on current collectors is advantageous for electron transport and electrolyte diffusion which can facilitate the electrochemical reaction. Our work not only demonstrated a facile hydrothermal method for ZnWO4 NWAs directly grown on Ni foam, but also revealed ZnWO4 to be a promising electrode for high-property supercapacitors.

The fluorescent microfibres with redox-responsive properties were prepared via the ionic self-assembly route from complexes of redox-responsive N,N-dimethylferrocenylmethylhexadecylammonium bromide and methyl orange dye molecule. The length of microfibres is from tens of micrometres to almost a millimetre and the width is about 500 mm to 2 μm. Steady state fluorescence spectroscopy shows strong fluorescent properties of the supramolecular self-assembled microfibres, which may have potential applications in electro-photo molecular switching device.

Porous reticular tin–iron oxide composite have been prepared by electrostatic spray deposition method for lithium-ion batteries. The structure of depsitied electrodes are investigated by X-ray Diffraction (XRD), which shows that the film is amorphous. Electrochemical characterization by galvanostatic charge-discharge tests demonstrate that the conversion reactions in these electrodes enable initial discharge capacities of about 1551 mAh/g for tin–iron oxide thin film electrode, and the reversible capacity stayed in the range of 769–601 mAh/g during the successive 30 cycles. The high porosity of the 3D reticular structure can provide more reaction sites on the electrode surface and accommodate volume variation of Sn particles during Li alloying–dealloying. Such a composite film are expected to be applied as attractive anodes for lithium-ion batteries.

Cyclodextrins (CDs) have been widely used in host-guest molecular recognition because of their chiral and hydrophobic cavities. For example, β-cyclodextrin (βCD) lodged as a molecular adaptor in protein pores such as α-hemolysin (αHL) is used for stochastic sensing. Here, we have tuned the cavity and overall size of βCD by replacing a single oxygen atom in its ring skeleton by a disulfide unit in two different configurations to both expand our ability to detect analytes and understand the interactions of βCD with protein pores. The three-dimensional structures of the two stereoisomeric CDs have been determined by the combined application of NMR spectroscopy and molecular simulation and show distorted conformations as compared to natural βCD. The interactions of these synthetic βCD analogues with mutant αHL protein pores and guest molecules were studied by single-channel electrical recording. The dissociation rate constants for both disulfide CDs from the mutant pores show ∼1000-fold increase as compared to those of unaltered βCD, but are ∼10-fold lower than the dissociation rate constants for βCD from wild-type αHL. Both of the skeleton-modified CDs show altered selectivity toward guest molecules. Our approach expands the breadth in sensitivity and diversity of sensing with protein pores and suggests structural parameters useful for CD design, particularly in the creation of asymmetric cavities.

A muti-component nanocomposite of nickel and manganese oxides with a uniformly dispersed microspherical structure has been fabricated by a hydrothermal synthesis method. The as-prepared nanocomposite has been employed as a sensing material for non-enzymatic glucose detection and shown excellent electrocatalytic activity, such as high sensitivities of 82.44 μA mM(-1) cm(-2) and 27.92 μA mM(-1) cm(-2) over the linear range of 0.1-1 mM and 1-4.5 mM, respectively, a low detection limit of 0.2 μM and a fast response time of

The stimuli-responsive vesicles were prepared via electrochemical oxidation on the mixture solution of ferrocenylmethyl-trimethylammonium iodide (FcMI) and sodium deoxycholate (NaDC). The vesicle structure and morphology are characterized respectively by transmission electron microscopy (TEM), dynamic light scattering (DLS) and atomic force microscopy (AFM). The vesicle shells can be clearly observed by TEM with the thickness ranging from several to several tens of nanometers and their outer diameters at the range of 50-200 nm. The formation of vesicular structures is also supported via AFM measurements, and the ratio of the diameter and height of the nanospheres was estimated to be ca. 10, indicating the shell collapse. The obtained results are significant for the preparation of smart supramolecular aggregates.

SnO2 nanospheres with a diameter of about 150 nm were synthesized by a hydrothermal method. They were assembled by numerous tetragonal nanocubes with an average size of 8 nm. Since the morphology of nanospheres agglomerated by nanocubes, the modulations of quantum confinement and large contact area were realized; this would serve as the basis for high sensitivity. The sensors based on the as-synthesized nanospheres showed good selectivity among different gases and superior sensitivity to ethanol compare with previous reports. The sensitivity could reach 53 to 50 ppm ethanol at a relatively low working temperature of 275 °C. A possible mechanism was proposed, which could be primarily related to the large surface-to-volume ratio and the small size effect of nanocubes.

Flower-like hierarchical nanostructures with Cu3BiS3 nanosheets as building blocks formed by in situ corrosion of matrix Cu3BiS3 microspheres were synthesized via a facile hydrothermal method. Their morphology, microstructure, and crystalline phase were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD), respectively. Pore-size distribution analysis indicated that both mesopores and micropores existed in the as-obtained product, which are favourable for increasing the surface-to-volume ratio. The optical band gap of the hierarchical Cu3BiS3 nanostructures was estimated to be ∼1.2 eV by UV-vis spectroscopy. Electrochemical measurements were also used to investigate the electrochemical Li+ intercalation performance for the flower-like Cu3BiS3 nanostructures. The results showed that the initial discharge capacity of the nanosheet based Cu3BiS3 hierarchical structures is 676 mA h g−1 which is larger than the theoretical value of Bi2S3 (625 mA h g−1), but it degraded quickly during subsequent cycles, and further improvement in cyclic stability is still needed for practical application in lithium-ion batteries.

Plate-like SnS2 nanostructures (such as stacked nanoplates and individual nanoplates) have been successfully synthesized under hydrothermal conditions without using any additive. Experimental parameters, such as reaction temperature and precursor concentration, play crucial roles in determining the morphologies and phase of final products. Furthermore, the formation mechanism of the stacked SnS2 nanoplates has also been discussed, based on the influence of the kinetics of nucleation and crystal growth. Morevoer, electrochemical measurements indicate the morphology-depending electrochemical properties of SnS2 materials in the application of lithium-ion batteries and the synthesized SnS2 nanomaterials could be expected to be potentially used in lithium ion batteries.

Two kinds of topochemical conversion routes from cobalt hydroxide precursors to cobalt oxide-based porous nanostructures are presented: pyrolysis in air and hydrothermal treatment by the Kirkendall diffusion effect. These cobalt hydroxide precursors were synthesized by a simple hydrothermal approach with sodium acetate as mineralizer at 200 °C. Detailed proof indicates that the process of cobalt hydroxide precursor growth is dominated by a nucleation, dissolution, renucleation, growth, and exfoliation mechanism. By the topochemical conversion processes several Co(3)O(4) nanostructures, such as cobalt oxide-coated cobalt hydroxide carbonate nanowires, cobalt oxide nanotubes, hollow cobalt oxide spheres, and porous cobalt oxide nanowires, have been synthesized. The obtained Co(3)O(4) nanostructures have also been evaluated as the anode materials in lithium-ion batteries. It was found that the as-prepared Co(3)O(4) nanostructures exhibited high reversible capacity and good cycle performance due to their porous structure and small size.

This article propounds a new strategy of preparing graphene by reducing GO with stannous ions for the synthesis of SnO2/graphene composites. As anode materials for lithium ion batteries, the composites showed good performance. This opens a new approach for the synthesis of graphene/metal-oxide composites with excellent properties.

A simple glucose-assisted hydrothermal process has been developed to design complex and functional ZnO/SnO2 nanostructures. In this synthesis, the abundant hydroxyl groups of glucose can ligate with Zn2+ and Sn4+, and induce nucleation. Furthermore, the glucose molecules can form stacking templates to direct the oriented attachment of nanorods and nanoplates due to the π–π electron interactions between glucose ligands. The growth mechanism is studied by changing the synthesis conditions. It is found that the morphologies of ZnO/SnO2 greatly depend on the concentrations of glucose and sodium hydroxide, as well as the molar ratios between Zn2+ and Sn4+. The as-synthesized samples are characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) techniques. In particular, gas sensing tests show that these ZnO/SnO2 nanostructures exhibit enhanced sensing properties to ethanol due to the formation of nano-heterojunctions and their unique morphologies.