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Layer-structured MoS2 is regarded as a promising anode material for potassium ion batteries. Herein, MoS2 nanosheets on N, P-codoping reduced graphene oxide (MoS2/N, P-rGO) have been successfully prepared via a facile two-step synthesis, where few-layered MoS2 nanosheets are chemically bonded onto the surface of N, P-rGO. As an anode material, MoS2/N, P-rGO exhibits a high specific capacity (462.7 mAh·g−1 at 100 mA·g−1 over 200 cycles), outstanding rate capability (224.9 mAh·g−1 at 20 A·g−1), and excellent cycle life (236.6 mAh·g−1 at 2 A·g−1 after 7,000 cycles), much better than those of MoS2 and MoS2/rGO. These advanced performances outperform most of the reported anode materials for potassium ion batteries to date. Meanwhile, the K-storage reactions of MoS2/N, P-rGO have been disclosed through in-situ and ex-situ characterizations. The kinetics analysis confirms that K-storage of MoS2/N, P-rGO is predominant by pseudo-capacitance.

Zhenyu Ye,* Zhaobi Zhu,* Jiaming Xie, Zhenyu Feng, Yecheng Li, Xiangrong Xu, Wei Li, Wei Chen Department of General Surgery, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, People’s Republic of China*These authors contributed equally to this workCorrespondence: Wei Chen; Wei Li Department of General SurgeryThe Second Affiliated Hospital of Soochow University, 1055 Sanxiang Road, Suzhou, Jiangsu 215004, People’s Republic of ChinaEmail chenwei1971best@126.com; li.wei1@yandex.comBackground: Circular RNAs (circRNAs) play an important role in the tumorigenesis of pancreatic cancer. However, the expression profiles and roles of circRNAs in pancreatic cancer remain largely unknown.Methods: To identify differentially expressed circRNAs (DEcircRNAs) between pancreatic cancer and matched normal tissues, bioinformatics analysis was performed. Hsa_circ_0000069 was identified by 0.bioinformatics analysis. In addition, the level of hsa_circ_0000069 in pancreatic cancer tissues and cell lines, and pancreatic cancer cell-derived exosomes were assessed using RT-qPCR assay.Results: The expression of hsa_circ_0000069 was markedly upregulated in pancreatic cancer tissues and cell lines. SCL/TAL1 interrupting locus (STIL) is the parent gene for hsa_circ_0000069, and its high expression was related to poor overall survival in patients with pancreatic cancer. In addition, downregulation of hsa_circ_0000069 markedly suppressed STIL expression, induced the apoptosis and cell cycle arrest, and inhibited the proliferation, migration and invasion in pancreatic cancer cells. Moreover, hsa_circ_0000069 knockdown inhibited the growth of xenograft pancreatic cancer tumors in vivo. Furthermore, human pancreatic duct epithelial cells (HPDE) are capable of internalizing SW1990 cell-derived exosomes, allowing the transfer of hsa_circ_0000069. Significantly, SW1990 cell-derived exosomes promoted the proliferation, migration and cell cycle progression of HPDE cells, whereas exosomes with downregulated hsa_circ_0000069 suppressed the proliferation, migration and cell cycle progression of HPDE cells, by suppressing STIL expression.Conclusion: Our results suggest that hsa_circ_0000069 knockdown could inhibit pancreatic cancer tumorigenesis and exosomes with downregulated hsa_circ_0000069 could suppress HPDE cell malignant transformation. Collectively, hsa_circ_0000069 might be a therapeutic target for the treatment of pancreatic cancer.Keywords: pancreatic cancer, hsa_circ_0000069, tumorigenesis, exosomes

Herein, nickel@nitrogen-doped carbon nanotubes (Ni@NCNTs) are prepared by a simple and reliable method with Ni-based complex as single-source precursor. Significantly, the formation of CNTs is not susceptible to the calcination temperature and ramping rate and Ni@NCNTs can be attained from 430 to 900 °C in an inert atmosphere. Then they are the first time to be applied as the anode material for sodium–ion batteries. The presence of Ni nanoparticles (NPs) facilitates the solid electrolyte interface film over the anode surface and improves the capacity retention of the host material, especially at the high rates. Furthermore, Na+ diffusion is reinforced after the introduction of Ni NPs. Ni@NCNTs obtained at 500 °C (Ni@NCNTs-500) exhibit the best capacity retention and rate capability. Kinetics analyses demonstrate the faster electron transportation and ion diffusion than others prepared at other temperatures. The surficial capacitance storage favors the fast electrochemistry kinetics. It delivers a high specific capacity (192 mA h g−1 at 0.5 A g−1), excellent cycling stability (103 mA h g−1 after 10,000 cycles at 10 A g−1), and outstanding high-rate capability up to 20 A g−1 (118 mA h g −1). The related full cells confirm a high energy density of 140 Wh kg−1 at 38.16 W kg−1 and 44.27 W h kg−1 at 762 W kg−1.

Smart materials that reversibly change color upon light illumination are widely explored for diverse appealing applications. However, light-responsive color switching materials are mainly limited to organic molecules. The synthesis of inorganic counterparts has remained a significant challenge because of their slow light response and poor reversibility. Here, we report a seeded growth strategy for the synthesis of TiO2−x/WO3·0.33H2O hetero-nanoparticles (HNPs) with networked wire-like structure of ∼ 10 nm in diameters that enable the highly reversible light-responsive color switching properties. For the TiO2−x/WO3·0.33H2O HNPs, Ti3+ species self-doped in TiO2−x nanoparticles (NPs) act as efficient sacrificial electron donors (SEDs) and Ti-O-W linkages formed between TiO2−x and WO3·0.33H2O NPs ensure the nanoscale interfacial contact, endowing the HNPs enhanced photoreductive activity and efficient interfacial charge transfer upon ultraviolet (UV) illumination to achieve highly efficient color switching. The TiO2−x/WO3·0.33H2O HNPs exhibits rapid light response ( 180 times). We further demonstrate the applications of TiO2−x/WO3·0.33H2O HNPs in ink-free, light-printable rewritable paper that can be written on freehand or printed on through a photomask using UV light. This work opens an avenue for designing inorganic light-responsive color switching nanomaterials and their smart applications.

Lithium-sulfur batteries have been attracting considerable research attention due to their high energy densities and low costs. However, one of their main challenges is the undesired shuttling of polysulfides, causing rapid capacity degradation. Herein, we report the first example of sulfiphilic VSe2 ultrafine nanocrystals immobilized on nitrogen-doped graphene to modify the battery separator for alleviating the shuttling problem. VSe2 nanocrystals provide numerous active sites for chemisorption of polysulfides as well as benefit the nucleation and growth of Li2S. Furthermore, the kinetic reactions are accelerated which is confirmed by higher exchange current density and higher lithium ion diffusion coefficient. And the first-principles calculations further show that the exposed sulfiphilic planes of VSe2 boost the redox of Li2S. When used as separators within the lithium sulfur batteries, the cell indicates greatly enhanced electrochemical performances with excellent long cycling stability and exceptional rate capability up to 8 C. Moreover, it delivers a higher areal capacity of 4.04 mAh·cm−2 as well as superior cycling stability with sulfur areal loading up to 6.1 mg·cm−2. The present strategy can encourage us in engineering novel multifunctional separators for energy-storage devices.

Ordered hierarchical architectures are attractive candidates for electrochemical energy storage applications. Herein, a facile self-template strategy is applied to prepare Fe7Se8 architectures with a monolithic structure via a self-synthesized single precursor and subsequent calcination at high temperature. With the support of oleylamine, the precursor is structurally targeted to engineer the Fe7Se8 microstructure, featuring nanorod bundles arranged along the longitudinal direction. Because of their ordered hierarchical structure, the Fe7Se8 nanorod bundles deliver a high reversible capacity of 300 mAh g−1 at 0.5 A g−1, along with exceptional rate capability up to 20 A g−1 and long-term cycle life over 8000 cycles, which represents the highest stability of Fe7Se8 anodes for sodium-ion batteries reported to date. The feasibility of the present strategy to prepare metal selenide structures highlights its promising potential for the rational and effective engineering of electrode materials responsible for the electrochemical performance of energy storage systems.

Novel luminescent vesicles with enhanced emission were successfully achieved for the first time by an amphiphilic europium complex through its spontaneously self-assembly in an ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF

Carbon-coated mesoporous Co9S8 nanoparticles supported on reduced graphene oxide (rGO) are successfully synthesized by a simple process. This composite makes full use of the protection of the carbon layer on the surface, the good conductivity and three-dimensional (3D) structure of rGO, the mesoporous structure and nanoscale size of Co9S8, thereby presenting the excellent electrochemical performances in potassium-ion batteries, 407.9 mAh·g−1 after 100 cycles at 0.2 A·g−1 and 215.1 mAh·g−1 at 5 A·g−1 in rate performances. After 1,200 cycles at 1.0 A·g−1, this composite still remains a capacity of 210.8 mAh·g−1. The redox reactions for potassium storage are revealed by ex-situ transmission electron microscope (TEM)/high-resolution TEM (HRTEM) images, selected area electron diffraction (SAED) patterns and X-ray photoelectron spectroscopy (XPS) spectra. The application of this composite as the host of sulfur for Li-S batteries is also explored. It sustains a capacity of 431.8 mAh·g−1 after 800 cycles at 3 C, leading to a degradation of 0.052% per cycle. These results confirm the wide applications of this composite for electrochemical energy storage.

The reversible photocatalytic color switching systems (PCSSs) driven by semiconductor nanoparticles have attracted considerable attention because of their wide applications. However, the developed semiconductor nanoparticles with photoreductive activity are mainly limited to TiO2-based photocatalysts, which greatly hinder their broad applications. Here we report a cocapping ligand-assisted strategy for the development of photoreductive BiOCl ultrathin nanosheets with abundant oxygen vacancies. Both the cocapping ligands and oxygen vacancies in BiOCl ultrathin nanosheets act as sacrificial electron donors to efficiently scavenge the photogenerated holes, endowing the BiOCl ultrathin nanosheets high photoreductive activity and thus enabling the photocatalytic color switching of redox dyes, such as methylene blue (MB) and neutral red. By successfully integrating the BiOCl ultrathin nanosheet/MB/H2O color switching system with poly(vinyl alcohol) hydrogel to fabricate a twistable gel film and simultaneously solving the dye-leaching issue of the gel film in a water environment, we further demonstrate its application in a colorimetric oxygen indicator for food packaging, exhibiting high sensitivity to monitor oxygen leakage by the naked eye. We believe the work opens a new avenue for designing photoreductive semiconductor nanomaterials to enrich the PCSSs and their applications.

Lithium–sulfur (Li–S) batteries have attracted much attention due to their ultrahigh theoretical specific capacity. However, serious capacity attenuation caused by shuttle effect still inhibits the performance improvement. Herein, a modified separator consists of the few-layer graphene as a highly conductive network and stable scaffold to support P-doped boron nitride (denoted as BN-P@GO) as the functional interlayer of Li–S batteries. The cell with the interlayer provides an initial discharge capacity as high as 1045.3 mAh g−1, and retains a high reversible capacity of 728.7 mAh g−1 at 1 C after 500 cycles with a capacity decay of 0.061% per cycle. Moreover, the rate capability is also superior to cells with BN@GO or BN-P interlayers, i.e. reversible capcity of 457.9 mAh g−1 even at 3 C. The excellent electrochemical performance is ascribed to the synergistic effect of physical barrier and chemical adsorption for dissolved polysulfides provided by the modified layer. Furhtermore, it also mitigates the polarization and promotes kinetic reactions of the cells. This work provides a concise and effective method for commercialization of lithium–sulfur batteries.

The dynamic dual-stimuli-responsive surface wrinkles on a bilayer film with high bistability are unattainable and attractive for the applications of smart windows and optical displays. Here, we report a new strategy in developing moisture and temperature dual-responsive surface wrinkles on the polyvinyl alcohol/polydimethylsiloxane (PVA/PDMS) bilayer film by rationally designing the modulus changes of the PVA skin layer upon moisture and temperature. By optimizing the thickness of the PVA layer to 4.5 μm, the as-prepared surface wrinkles show long-awaited properties, such as fast response time, excellent reversibility without degradation of optical contrast, and high light transmittance modulation, which greatly outperforms the reported surface wrinkles. Moreover, the surface wrinkles on the bilayer film remain highly bistable without additional energy consumption for more than five months in ambient room conditions both in the opaque and transparent states. These promising dual-stimuli-responsive surface wrinkles on bilayer films hold great promises for various applications triggered by moisture and temperature, such as smart windows and rewritable optical displays.

Novel approaches are required to overcome the challenges associated with conventional microRNA (miRNA) detection methods and realize the early diagnosis of diseases. This work describes a novel label-free surface-enhanced Raman spectroscopy (SERS) method for the detection of the miRNA biomarkers for pneumoconiosis on a three-dimensional Au-coated ZnO nanorod array (Au-ZnO NRA). The Au-ZnO NRA substrate, which was fabricated via a modified seeding method combined with ion sputtering, provided a high enhancement factor and good spatial uniformity of the signal. With the Au-ZnO NRA, the SERS spectra of miRNAs were obtained in 30 s without labeling at room temperature. Density functional theory calculations were performed to understand the structural fingerprints of the miRNAs. Principal component analysis was carried out to identify the pneumoconiosis biomarkers based on their fingerprint SERS signals. Dual-logarithm linear relationships between the SERS intensity and the miRNA concentration were proposed for quantitative analysis. The label-free SERS method has limits of detection on the femtomolar level, which is much lower than the concentrations of the miRNA biomarkers for pneumoconiosis in lung fibroblasts.

Lithium-sulfur (Li-S) battery as one of the most attractive candidates for energy storage systems has attracted extensive interests. Herein, for the first time, hierarchical flower-like cobalt phosphosulfide architectures (defined as “CoSP”) derived from Prussian blue analogue (PBA) was fabricated through the conversion of Co-based PBA in PxSy atmosphere. The as-prepared polar CoSP could effectively trap polysulfides through the formation of strong chemical bonds. In addition, after the combination of CoSP with high conductive rGO, the obtained CoSP/rGO as sulfur host material exhibits ultralow capacity decay rate of 0.046% per cycle over 900 cycles at a current density of 1 C. The excellent performance could be attributed to the shortened lithium diffusion pathways, fastened electron transport ability during polysulfide conversion, and increased much more anchor active sites to polysulfides, which is expected to be a promising material for Li-S batteries. It is believed that the as-prepared CoSP/rGO architectures will shed light on the development of novel promising materials for Li-S batteries with high cycle stability.

P4Se3 microparticles are successfully synthesized by simple heating of selenium and amorphous red phosphorus at low temperature. These orthorhombic-phase microparticles exhibit a high reversible capacity of 654 mA h g−1 at 200 mA g−1 after 70 cycles and an excellent rate capability with a reversible capacity of 486 mA h g−1 at 3 A g−1 as an anode material in sodium-ion batteries. This superior electrochemical performance is attributed to the formation of Na2Se and Se during cycling with better conductivities (≈10−6 and ≈10−5 S cm−1) and the dominant position of capacitance behavior, which all accelerate kinetic behavior.

The extensive use of chlorobenzene in chemical, pharmaceutical, and agrochemical industries poses a severe health hazard to human beings, because it is highly toxic. The detection of chlorobenzene by metal oxide gas sensors is difficult, owing to its chemically inert molecular structure. In this study, well-dispersed Pd nanoparticles were deposited on porous ZnO nanoplates via surface ion exchange, followed by H2 reduction. The preparation process effectively prevented the aggregation and uncontrollable growth of Pd particles. A gas-sensing test was conducted, and the modification of size-controlled Pd nanoparticles was found to effectively enhance the sensing properties of porous ZnO nanoplates to chlorobenzene over 300 °C (higher sensitivity at a low operating temperature). At 440 °C, 5% Pd@ZnO sensor showed a drastic increase in response by nearly 4.5-fold, as well as excellent sensing selectivity to chlorobenzene. Its repeatability and stability were acceptable. As known, Pd nanocatalysts contribute to the oxidation of chlorinated aromatic compounds. Pd@ZnO sensors generated more catalytic sites and oxygen species (confirmed by XPS), thus enhancing chlorobenzene oxidation and improving the sensitivity of ZnO-based gas sensors.

Metal-organic frameworks (MOFs)-derived metal chalcogenides/carbon, has been developed as promising anode materials for lithium/sodium ion batteries. However, they are not explored for potassium-ion batteries yet. Here, ZIF-67 is employed as a self-sacrificed template to synthesize Co 0.85 Se nanoparticles in N-doped carbon as an anode material for potassium-ion batteries. In this composite, N-doped carbon enhances the electron conductivity , cushions the volume change and inhibits the aggregation of Co 0.85Se upon cycling. Meanwhile, mesoporous structure shortens the diffusion distance of potassium ions, as well as increases the contact between electrolyte and electrode. These features endow this composite superior performances. It delivers a specific capacity of 114.7 mA h g−1 at 1000 mA g−1 after 250 cycles. At 2.0 A g−1, the specific capacity still maintains at 110.7 mA h g−1. The electrochemical performances of full cells based on Co0.85 Se@NC as an anode material are also investigated. The result greatly spurs the exploration of metal chalcogenides as anode materials for potassium ion batteries.

In this work, the fishlike phase diagram of the H2O/[Bmim][AOT]/[Bmim][PF6]/n-alcohol as a function of temperature (T) and the mass fraction of [Bmim][AOT] (with or without n-alcohol) in the total mixture (γ) has been observed for the first time at several mass ratios of [Bmim][PF6] to H2O (α) and with different n-alcohols. The larger area of the three-phase region occurs at α ≤ 0.500, and the resulting fish shapes are similar to each other. For a given α, a temperature scan (from lower to higher) at several γ values reveals that the present system forms an upper phase microemulsion first and then a lower phase microemulsion. The formation of hydrophobic ionic liquid-in-water (HIL/W) microemulsion at low temperature and water-in-hydrophobic ionic liquid (W/HIL) microemulsion at high temperature was confirmed by dynamic light scattering and small-angle X-ray scattering techniques. Here, the phase sequence that occurred during the temperature scan is opposite to that of a classic H2O/NaAOT/oil system. At th...

A 3D thermal response model is developed to evaluate the thermal behavior of glass fiber/phenolic composite exposed to heat flux on one side. The model is built upon heat transfer and energy conservation equations in which the heat transfer is in the form of anisotropic heat conduction, absorption by matrix decomposition, and diffusion of gas. Arrhenius equation is used to characterize the pyrolysis reaction of the materials. The diffusion equation for the decomposition gas is included for mass conservation. The temperature, density, decomposition degree, and rate are extracted to analyze the process of material decomposition, which is implemented by using the UMATHT (User subroutine to define a material’s thermal behavior) and USDFLD (User subroutine to redefine field variables) subroutines via ABAQUS code. By comparing the analysis results with experimental data, it is found that the model is valid to simulate the evolution of a glass fiber/phenolic composite exposed to heat flux from one side. The comparison also shows that longer time is taken to complete the pyrolysis reaction with increasing depth for materials from the numerical simulation, and the char region and the pyrolysis reaction region enlarge further with increasing time. Furthermore, the decomposition degree and temperature are correlated with depths, as well as the peak value of decomposition rate and the time to reach the peak value.

Photoreversible color switching that can change colors with fast response and high stability is urgently desired in color-on-demand applications. Yet, developing such materials has long been a significant challenge. In this work, a strategy based on the integration of TiO2 nanoparticle (NP) photocatalytic color switching of redox dyes and poly(vinyl alcohol) gel matrix could produce robust and flexible photochromic gels (FPGs) that exhibit fast light-responsive time and high photoreversible stability. Benefited by the soft network structures and monomeric form of redox dyes in the FPG maintained by poly(vinyl alcohol) and ethylene glycol molecules, as well as enhanced photoreductive activity of TiO2 NPs modified by both surface ligands and oxygen vacancies, the FPG exhibits long photoreversible switching cycles (≥50 times), decoloration in a short period of less than 8 s upon UV illumination, and recoloration in 16 min in ambient air and rapidly in 140 s upon near-infrared light illumination. Consequently...

Graphene-like N,S-codoped bio-carbon nanosheets (GNSCS) were prepared by a facile and environment -friendly NaCl non-aqueous ionic liquid route to house sulfur for lithium-sulfur battery. The natural nori powder was calcined at 900°C for 3 h under Ar, in which NaCl non-aqueous ionic liquid can exfoliate carbon aggregates into nanosheets. The structural characterization of GNSCS by a series of techniques demonstrates the graphene-like feature. When evaluated as the matrix for sulfur cathode, GNSCS/S exhibits more prominent cycling stability and rate capability. A discharge capacity of 548 mA h g−1 at a current density of 1.6 A g−1 after 400 cycles was delivered with a capacity fade rate of only 0.13% per cycle and an initial Coulombic efficiency (CE) as high as 99.7%. When increasing the areal sulfur loading up to 3 mg cm−2, the discharge capacity can still be retained at 647 mA h g−1 after more than 100 cycles with a low capacity degradation of only ~0.30% per cycle. The features of N/S dual-doping and the graphene-like structure are propitious to the electron transportation, lithium-ion diffusion and more active sites for chemically adsorbing polysulfides. It is anticipated that other functional biochar carbon can also be attained via the low-cost, sustainable and green method.

Ultralong MnO2 nanowires, which can effectively catalyze H2O2 to generate radicals for degrading methylene blue (MB) at low temperature (5.0 °C), are prepared by hydrothermal method. The MnO2 nanowires catalytically degrade 98.1% of MB within 30 min and degradation efficiency is about 93.0% after 5 cycles at 5.0 °C. The yield of ·OH and ·O2− radicals within 30 min is 39.33 $${\text{mg}}\;{{\text{g}}_{{\text{Mn}}{{\text{O}}_2}}}^{{ - 1}}$$ and 1.29 $${\text{mg}}\;{{\text{g}}_{{\text{Mn}}{{\text{O}}_2}}}^{{ - 1}}$$ , respectively. Excellent catalytic degradation performances for MB at 5.0 °C including catalytic efficiency, reusability and yield of radicals concerning synthesized ultralong MnO2 nanowires are revealed.

Novel In2O3-SnO2 hybrid sensing nanostructures with porous nature were successfully prepared and characterized by various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and high resolution transmission electron microscopy (HRTEM). Gas sensing properties of the fabricated sensor based on the as-prepared In2O3-SnO2 hybrid nanostructures were systematically investigated and compared with those of pure SnO2. The hybrid nanostructures containing 3% In2O3 exhibit the highest response value of 30.7–100 ppm formaldehyde at 100 °C, which was 14 times higher than that of pure SnO2. Moreover, gas sensors based on the as-prepared In2O3-SnO2 hybrid nanostructures also exhibit high stability and good selectivity for formaldehyde. The enhanced sensing performances of formaldehyde were mainly attributed to the formation of n-n heterojunctions and the synergistic interaction between In2O3 and SnO2.

The indoor volatile organic compounds (VOCs) have caught much attention because millions of people are suffering from indoor air pollution. To detect VOCs, various gas sensors with fast response, high sensitivity and high stability have been fabricated by nanocomposite technology. In this study, highly dispersed Au nanoparticles are deposited on porous ZnO nanoplates (Au@ZnO) via ion exchange method from hydrozincite [Zn 5 (CO 3 ) 2 (OH) 6 ] without the addition of any surfactants. By immersing hydrozincite precursors into 0.1%–5% HAuCl 4 solutions and followed by annealing, several Au@ZnO sensors with size-limited Au nanoparticles are fabricated for the detection of nine types of VOCs. Comparing with pure ZnO nanoplates, the as-prepared Au@ZnO sensors show enhanced sensitivity by 2–9 times at 400 °C toward all nine types of VOCs. Also, fast response/recovery time and fine repeatability in the gas-sensing tests are attained. More oxygen species and active sites to the adsorbed VOCs molecules are generated by Au@ZnO hybrids, which lead to the improvement of ZnO-based gas sensor limitation.

It has been a challenge to design a novel structure for effectively improving the efficiency of charge carriers' separation and transfer. Herein, a CdS/ZnS heterostructure with a tunable Cd/Zn ratio was engineered on reduced graphene oxide (RGO) by a one-pot hydrothermal method followed by in situ formation of Au nanocrystals, which combined the strong electron capture ability of a noble metal and transfer capability of graphene. The CdS/ZnS-RGO architecture was featured by the anisotropic growth of ZnS nanoparticles on a CdS nanorod tip. Relying on the low lattice mismatch, the epitaxial growth of ZnS on CdS as well as CdS on graphene was realized, which rendered the immediate contact of interfaces between different phases. Due to the three features of CdS/ZnS heterostructures, noble metal and graphene being designed together in one material, the Au-CdS/ZnS-RGO heterostructure offered an excellent photocatalytic H2 evolution rate as high as 9.96 mmol h−1 g−1 under visible-light irradiation and photocatalytic stability over 30 h. The results confirmed the efficient separation and transfer of photogenerated electrons and holes.

Although the melt-diffusion method was applied to fabricate sulfur-based cathode for lithium–sulfur batteries, more efforts should be devoted to the development of synthetic methodology of sulfur-based hybrids. Herein, we report a sulfur–hydrazine hydrate chemistry-based method to prepare the composite of sulfur and N-doped reduced graphene oxide (S@N-rGO) with 76% sulfur content. Relying on the reaction of sulfur and hydrazine hydrate, cyclo-sulfur was broken to form soluble polysulfides. The subsequent refluxing with GO suspension rendered the transformation of soluble polysulfides to sulfur crystal homogeneously deposited on N-rGO due to direct nucleation from solution. Simultaneously, the nitrogen doping of GO was realized with hydrazine hydrate as doping agent in the one-pot route. The as-obtained S@N-rGO composite displayed a good rate capability and excellent capacity stability up to 300 cycles. This study may provide a new and facile method to construct the composite of sulfur and N-doped carbonaceous matrix, which makes the hybrid a competitive cathode material for lithium–sulfur batteries (LSBs).

Hard carbon has been identified as a promising anode material for sodium-ion batteries (SIBs). Herein, a facile self-templating strategy has been developed for the kilogram-scale preparation of N,O-codoped hierarchical porous hard carbon cuttlefish-like nanowire bundles (denoted as NOHPHC cuttlefishes). The unique nanoarchitecture leads to ultrafast pseudocapacitive sodium storage, excellent reversibility, and negligible degradation of the host material. NOHPHC delivers a high reversible capacity of 184 mA h g−1 at 0.5 A g−1, which is maintained at 114 mA h g−1 at 5 A g−1 for over 30 000 cycles, as well as exceptional rate capability of up to 20 A g−1 with a capacity of approximately 100 mA h g−1. Importantly, samples prepared before and after kilogram scaling are comparable in performance. Coupled with a Na3V2(PO4)3/C cathode, a full cell successfully obtains a high energy density of 52.6 W h kg−1 at 50 W kg−1 and 34 W h kg−1 at 1.4 kW kg−1.

Integration of bicomponents into a greater object or assemblage is a new avenue to acquire multifunctionality for metal oxide-based anodes for lithium-ion batteries (LIBs). Herein, we report a versatile means by which precursors serve as self-sacrificing templates to form architectures of SnO2 phase and other metal oxides. The vital challenge is the determination of appropriate synthetic system that can benefit the formation of respective precursors in a structure or single-source precursors of tin and other metal species. In the current work, by the aids of synergy action between l-proline and ethylene glycol (EG), precursors containing two metal ions are generally fabricated. Adequate flexibility of the present method has been achieved for SnO2/MxOy hierarchical hybrids, including Mn2O3, Co3O4, NiO, and Zn2SnO4, by calcination of their corresponding SnMn, SnCo, SnNi, and SnZn precursors, respectively. When evaluated as anode materials for LIBs, the obtained SnO2/Mn2O3 homogeneous hybrids, as expected, show higher specific capacity and ultralong cycling stability, gaining a reversible specific capacity of 610.3 mA h g–1 after 600 cycles with only decay of 0.29 mA h g–1 per cycle at 1 A g–1 and 487 mA h g–1 after 1001 cycles at a high current density of 2 A g–1.

The realization of accurate and real-time monitoring of hazardous gases has received much recent attention. To facilitate the detection of toxic gases, multifarious nanofabrication techniques have been explored to make various gas sensors with excellent sensitivity, good reliability, and fast response/recovery available. In this contribution, two-dimensional (2D) porous ZnO nanoplates (NPs) hyper-dispersed with low concentration of Pt were synthesized via a convenient hydrothermal reaction followed by in-situ calcination when aged sensor film on the alumina tubes. Applying acetone as a probe molecule, gas sensing characteristics of both pristine ZnO and Pt-doped ZnO NPs were systematically investigated. The results have been proved that the as-prepared 0.01 mol% Pt-doped ZnO NPs sensor showed marked sensitivity toward acetone over 11 times higher than that of the pure ZnO sensor. Also, 0.01% Pt-doped ZnO NPs sensor exhibited superior selectivity against other reference gases, and outstanding trace sensing capability (Ra/Rg = 1.64–100 ppb). Probably both the hyper-dispersion of Pt species and the abundant surficial oxygen species jointly responsible for enhanced sensing performance of the obtained hybrid materials.

High-safety and low-cost aqueous Zn-ion batteries have triggered an astounding investigation surge in the last 5 years and are becoming competitive alternatives for grid-scale energy storage. However, the implementation of this promising technology is still plagued by the lack of effective and affordable cathode materials that can enable high energy densities and an exceptional cycling stability. Herein, a novel vanadium-based oxide cathode based on MgV2 O6 ·1.7H2 O nanobelts, which delivers a high capacity (425.7 mAh g-1 at 0.2 A g-1 ), a robust rate capability (182.1 mAh g-1 at 10 A g-1 ), and an ultrastable cycle without any visible deterioration, as well as an adequate energy density (331.6 Wh kg-1 ), is developed. Such excellent electrochemical Zn-ion storage performance is believed to result from the fast ion-diffusion kinetics boosted by a stable layered structure and an ultrahigh intercalation pseudocapacitance reaction, which are also benefited by a typical H+ /Zn2+ co-insertion mechanism, accompanied by an atypical Zn2+ intercalation chemistry with a partial but irreversible Mg2+ -Zn2+ ion-exchange reaction during the initial discharge. These results provide key and enlightening insights into the design of high-performance vanadium oxide cathode materials.

Mn3O4 nanomaterials exhibit intrinsic molecular oxygen activation properties in biomimetic and environmental catalysis. Modulating the oxygen vacancies (OVs) and identifying the oxygen activation mechanism of Mn3O4 nanomaterials are vital for designing high-performance nanozymes. Herein, the synthesized OV-Mn3O4 Nanoflowers (NFs) possesses different OVs concentrations by regulating oxygen partial pressure. The oxidase-mimicking OV-Mn3O4 NFs showed high catalytic reaction efficiency (kcat/Km) of 1.88 × 10−8 s−1 μM−1, 26.86-fold higher than Mn3O4 with poor-OVs (7.00 × 10-10 s-1 μM-1). The changes of substrates absorption, reactive oxygen species (ROS), and Mn2+/Mn3+/Mn4+ contents are attempted to illustrate clearly with the participation of OVs. Modulation OVs of Mn3O4 nanozymes can enhance the oxygen storage capacity and increase Mn species with lower valence states, which can generate abundant and multifarious ROS for the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) substrates. Besides, l -cysteine ( l -Cys) is a pivotal amino acid for antiaging and reducing melanin. Colorimetric detection for l -Cys was established based on the enhanced oxidase-like properties of OV-Mn3O4. Compared with Mn3O4 NFs, OV-Mn3O4 NFs are exhibited more sensitive limit of detection (1.31 μM versus 5.69 μM, S/N = 3). Overall, the in-depth mechanism understanding of OVs can provide new perspective to rational design nanozymes and detection sensor with satisfactory property.

Soft materials of europium β-diketonate complexes constructed in lyotropic liquid crystals (LLCs) mediated by ionic liquids (ILs) are impressive for their excellent luminescence performance and stability. For the aim to further improve their mechanical processability and luminescent tunablility, the polyoxyethylene phytosterols (BPS-n) were introduced here as structure directing agents to prepare relatively "rigid" lamellar luminescent LLCs in 1-butyl-3-methyl-imidazolium hexafluorophosphate by doping europium β-diketonate complexes with different imidazolium counterions. As a result of the solvophobic sterol ring structure of BPS-n, the more effective isolation and confinement effects of europium complexes could be achieved. The longest fluorescence lifetime and the highest quantum efficiency reported so far for europium containing lyotropic organized soft materials were thus obtained. Changing the molecular structures of BPS-n with different oxyethylene chains or doped complexes with imidazolium counterions of different alkyl chain lengths, the spacings of lamellar LLC matrixes and position of dispersed complexes became tunable. The measured luminescent and rheological properties for such composite LLCs showed a dependence on the rigidity and isolation capability afforded by sterol molecules. It was also found that the increase of counterion alkyl chain length would weaken the LLC matrix's confinement and isolation effects and therefore exhibit the deteriorated luminescence performance. The enhanced luminescence efficiency and stability of doped BPS-n LLCs reflected the excellent segregation of europium complexes from each other and therefore the reduced self-quenching process. The obtained results here present the designability of LLC matrixes and their great potential to promote achieving the luminescence tunability of soft materials.

Herein, we have designed and first synthesized a unique ternary hybrid structure by simultaneously growing SnS2 and MoS2 particles on graphene sheets (denoted as MoS2/SnS2-GS) via one-pot hydrothermal route. The charge incompatibility between MoO42– and graphene oxide with negative charged functional groups on surface can be compromised with the aid of Sn4+ cations, which renders the final formation of SnS2 and MoS2 on GS surface. This is the first report of the cohybridization of MoS2 and SnS2 with GS matrix from anionic and cationic precursors in the absence of premedication of graphene surface. When MoS2/SnS2-GS acts as anodes for lithium-ion batteries, the hybrids exhibit much better cycling stability than MoS2-GS and SnS2-GS counterparts. The compact adhesion of MoS2/SnS2 nanoparticles helps offset the undesired result of destruction of electrode materials resulting from volume expansion during repeated cycles. Furthermore, by combination with their synergetic effect on interface and the presence of ...

Redox-active organic polymers are promising cathode electrodes owing to the advantages of open and flexible frame-works, renewability and environmental friendliness. Sodium salt of poly (2, 5-dihydroxy-p-benzoquinonyl sulfide)/RGO (Na2PDHBQS/RGO) composite has been fabricated via a convenient route and applied as a high performance and stable cathode for sodium ion batteries. The Na2PDHBQS/RGO was investigated in ether-based electrolyte, which demonstrated better electrochemical performances (228, 214, 203, 193, 172 and 147 mAh g−1 at 0.1, 0.2, 0.4, 0.8, 2 and 4C, respectively) than that in traditional ester-based ones. The high specific capacity, excellent cycle stability and reversibility of Na2PDHBQS/RGO may be attributed to the special porous structure, enhanced electronic conductivity by the introduction of RGO and fast sodium ion and electron diffusion rate in ether-based electrolyte. In addition, the Na2PDHBQS/RGO cathode has been assembled with disodium terephthalate (Na2TP) anode to compose a full cell for the first time, which presents an initial reversible capacity of 210 mAh g−1 at 0.1C.

The significant issues with alkali metal batteries arise from their poor electrochemical properties and safety problems, limiting their applications. Herein, TiO2 nanoparticles embedded into N-doped porous carbon truncated ocatahedra (TiO2 ⊂NPCTO) are engineered as a cathode material with different metal anodes, including solid Na or K and liquid Na-K alloy. Electrochemical performance and kinetics are systematically analyzed, with the aim to determine detailed electrochemistry. By using a galvanostatic intermittent titration technique, TiO2 ⊂NPCTO/NaK shows faster diffusion of metal ions in insertion and extraction processes than that of Na-ions and K-ions in solid Na and K. The lower reaction resistance of liquid Na-K alloy electrode is also examined. The higher b-value of TiO2 ⊂NPCTO/NaK confirms that the reaction kinetics are promoted by the surface-induced capacitive behavior, favorable for high rate performance. This superiority highly pertains to the distinct liquid-liquid junction between the electrolyte and electrode, and the prohibition of metal dendrite growth, substantiated by symmetric cell testing, which provides a robust and homogeneous interface more stable than the traditional solid-liquid one. Hence, the liquid Na-K alloy-based battery exhibits to better cyclablity with higher capacity, rate capability, and initial coulombic efficiency than solid Na and K batteries.

We report a unique successive hydrothermal deposition method for the heteroepitaxial growth of well-dispersed crystalline Co3O4 nanoparticles on single-crystalline porous ZnO nanoplates toward a Co3O4/ZnO nanocomposite catalyst. The specific heteroepitaxial crystal faces between Co3O4 and ZnO limit the size of Co3O4 particles to be approximately 5 nm and allow the exposure of more active sites. The intermediate of hydrozincite [Zn5(CO3)2(OH)6] plays a role as template in creating porous ZnO nanoplates and oriented Co3O4 grains via thermal decomposition process. The active exposure of the catalyst is probed by CO oxidation. The nanocomposite exhibits significantly enhanced catalytic efficiency towards CO oxidation at temperatures ranging from 30 to 115 °C, in comparison with a homogeneous Co3O4 sample and one-step Co/ZnO products.

The indoors volatile organic compounds (VOCs), which can be classified into seven groups as oxy hydrocarbons, halogenated hydrocarbons, aromatic hydrocarbons, aliphatic hydrocarbons, terpenes, esters and aldehydes, have been brought to the forefront because millions of people are suffering from indoor air pollution. In this study, well-dispersive Au nanoparticles were deposited on porous single-crystalline ZnO nanoplates (Au@ZnO) via photodeposition free from additives for the gas sensing detection of the seven-group VOCs. The structure and morphology of Au@ZnO nanoplates were characterized by TEM, HRTEM, mapping and XRD. Comparing to pure ZnO nanoplates, the Au@ZnO sensor has prominent enhanced performance at 360 °C with high sensitivity (about 2–9 times for each group of VOCs), fast response/recovery time (less than 30/14 s) and stable repeatability (relative standard deviation less than 0.039) in the gas sensing tests. The fluctuation range of relative humidity is less than 80% and the contribution ratios of oxy hydrocarbons, halogenated hydrocarbons, aromatic hydrocarbons, aliphatic hydrocarbons, terpenes, esters and aldehydes were 0.1678, 0.0989, 0.0826, 0.0739, 0.2396, 0.1887, 0.1495, respectively. Finally, the possible sensing mechanism was discussed based on these results.

A non-aqueous solution of tetra-n-butylammonium fluoride (TBAF) in ethylene glycol has been tried for the first time as a supporting electrolyte for the electropolymerization of 3-aminophenylboronic acid (APBA). Unlike the traditional acidic aqueous solution, the present medium needs no exogenous protons; moreover, the presence of CF3COOH is found to be unfavorable for the polymerization. The protons are in situ generated by the reaction between the boronic acid group on APBA and 1,2-dihydroxyl on ethylene glycol. So, ethylene glycol serves as not only the solvent but also the proton source. As a part of the supporting electrolyte, F(-) is found to be involved in the electrochemical synthesis of poly(3-aminophenylboronic acid) (PAPBA), but it is not indispensable. Studies on the electropolymerization process indicate that the size of the ions in the electrolyte affects the rate of the doping/dedoping process. The smaller the cation, the easier the doping/dedoping process, and the better the stability of the grown film. As demonstrated by Fourier transform infrared spectra, UV-vis spectra, and scanning electron microscopy, the obtained PAPBA is a cross-linked nanoporous polymer membrane that has a good adherence to the glassy carbon electrode.

Functional gels from self-assembled macrocyclic host molecules towards diversified applications are promising yet challenging. In this work, we report a novel protocol to build up organogel materials via the delicate solvent balance. By utilization of good/poor solvent or nanoprecipitation method, self-assembly of β-cyclodextrin with abundant hydrogen bonding sites were triggered, generating sheet-like structures at microscale. The gels exhibit fine colloidal stability, robust mechanical strength and thermo-resistance properties, which can also be regulated by varying poor solvent (alcohols) compositions. Also, the polar organic solvent systems as well as the intrinsic micro/nanopockets among sheet structures provided space for entrapping fluorescent dyes. Due to the excellent properties of the gels, we successfully applied the gels as vessel supporting materials.

Transition metal oxides nanoparticles have shown enzyme-mimetic performance. It was demonstrated that the Co3O4@β-cyclodextrin nanoparticles (Co3O4@β-CD NPs) showed a higher peroxidase-mimicking catalytic activity than pure Co3O4 NPs. β-CD molecules were coated onto the surface of Co3O4 NPs via a one-pot synthesis method. Co3O4@β-CD NPs displayed higher affinity to 3,3′,5,5′-tetramethylbenzidine (TMB) through Michaelis-Menten mechanism after modification with β-CD. The catalytic efficiency of Co3O4@β-CD NPs for TMB oxidation was 9.5-fold higher than that of the pure Co3O4 NPs because of the effective host-guest interactions between Co3O4@β-CD NPs and TMB. Further, the hydrophobic cavity of β-CD while hosting TMB could reduce the transfer distance of electrons between TMB and Co3O4 catalyst, which could lead to faster oxidation of TMB. The synergistic effects between Co3O4 and β-CD enhanced the peroxidase-mimicking property. The efficient and visual colorimetric determination of Ascorbic Acid (AA) assay was achieved. The limit of detection was 1.09 μM (S/N = 3) and the linear range was 10–60 μM based on the Co3O4@β-CD NPs peroxidase-mimicking-mediated 3.0-fold signal magnification strategy. Moreover, the outstanding selectivity toward the detection of AA was achieved, which could exhibit prospects in biomedical analysis.

Benzene, toluene, ethyl benzene and xylene (BTEX) used in petroleum and industrial products, are highly toxic in nature and threaten human health. It is necessary to develop efficient ppm-level detection by a cost effective and available online technique. An economically viable gas sensor based on boron nitride quantum dots (BNQDs) decorated ZnO nanoplates has been fabricated for sensing BTEX vapors. Pure ZnO nanoplates, BNQDs and ZnO-BNQDs were synthesized by solvothermal method and characterized using XRD, HRTEM, SEM and EDAX. The sensing response of ZnO-BNQDs towards BTEX gases was markedly enhanced compared with that of pure ZnO, especially to xylene displaying more than 3.5 times sensitivity. ZnO-BNQDs sensor showed almost unbated response over a period of 50 days. Also, the response to changed humidity was studied. The results investigated by XPS and BET show that BNQDs decoration can generate active sites and more oxygen vacancies on ZnO substrate surface for catalytic oxidation of BTEX gas molecules.

Lithium–sulfur batteries are considered to be one of the most promising energy-storage systems because of their high theoretical energy density, as well as low cost, nontoxicity and natural abundance of sulfur. However, their poor cycling stability mostly originates from the shuttling of polysulfides which hinders their future practical applications. Here, multi-shelled CoP nanospheres are designed as a coated separator material for Li–S batteries for the first time. Conductive CoP can efficiently anchor polysulfides not only owing to its polar character but also its partial natural surface oxidation feature as evidenced by XPS results, which further activates Co sites for chemically trapping polysulfides via strong Co–S bonding. Furthermore, the unique multi-shelled structure can capture polysulfides to alleviate the “shuttle effect”. Consequently, the battery using a CoP coated separator exhibits outstanding cycling stability with a capacity degradation of 0.078% per cycle over 500 cycles at a current density of 1 C and excellent rate performance (725 mA h g−1 at 5 C). It is also worth noting that a high areal capacity of 3.2 mA h cm−2 can be achieved even with a sulfur loading of 3.24 mg cm−2. Our approach demonstrates the convenient fabrication and application potential for a multi-shelled CoP nanosphere modified separator for highly efficient Li–S batteries.

Sodium-ion batteries (SIBs) are considered promising next-generation energy storage devices. However, a lack of appropriate high-performance anode materials has prevented further improvements. Here, a hierarchical porous hybrid nanosheet composed of interconnected uniform TiO2 nanoparticles and nitrogen-doped graphene layer networks (TiO2 @NFG HPHNSs) that are synthesized using dual-functional C3 N4 nanosheets as both the self-sacrificing template and hybrid carbon source is reported. These HPHNSs deliver high reversible capacities of 146 mA h g-1 at 5 C for 8000 cycles, 129 mA h g-1 at 10 C for 20 000 cycles, and 116 mA h g-1 at 20 C for 10 000 cycles, as well as an ultrahigh rate capability up to 60 C with a capacity of 101 mA h g-1 . These results demonstrate the longest cyclabilities and best rate capability ever reported for TiO2 -based anode materials for SIBs. The unprecedented sodium storage performance of the TiO2 @NFG HPHNSs is due to their unique composition and hierarchical porous 2D structure.

The first synthesis of MnO@Mn3 O4 nanoparticles embedded in an N-doped porous carbon framework (MnO@Mn3 O4 /NPCF) through pyrolysis of mixed-valent Mn8 clusters is reported. The unique features of MnO@Mn3 O4 /NPCF are derived from the distinct interfacial structure of the Mn8 clusters, implying a new methodological strategy for hybrids. The characteristics of MnO@Mn3 O4 are determined by conducting high angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and electron energy loss spectroscopy (EELS) valence-state analyses. Due to the combined advantages of MnO@Mn3 O4 , the uniform distribution, and the NPCF, MnO@Mn3 O4 /NPCF displays unprecedented lithium-storage performance (1500 mA h g-1 at 0.2 A g-1 over 270 cycles). Quantitative analysis reveals that capacitance and diffusion mechanisms account for Li+ storage, wherein the former dominates. First-principles calculations highlight the strong affiliation of MnO@Mn3 O4 and the NPCF, which favor structural stability. Meanwhile, defects of the NPCF decrease the diffusion energy barrier, thus enhancing the Li+ pseudocapacitive process, reversible capacity, and long cycling performance. This work presents a new methodology to construct composites for energy storage and conversion.