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In this paper, a simple colloidal crystal-templating method assisted by a hydrothermal process has been proposed to prepare novel three-dimensionally ordered macroporous (3DOM) TiO2@nanosheet SnS2 heterojunction photocatalysts. The photoactivities of all the obtained samples were measured by the photodecomposition of rhodamine B (RhB), the photoreduction of Cr(VI) and photocatalytic hydrogen generation from water splitting. In comparison with pure SnS2 nanosheets and 3DOM TiO2, the 3DOM TiO2@SnS2 sample with a Sn/Ti molar ratio of 7.5 : 100 showed the highest photocatalytic activity for wastewater purification (kapp for RhB solution = 0.035 min−1 and for Cr6+ solution = 0.0845 min−1) and hydrogen generation under visible light irradiation. By means of ultraviolet-visible diffuse reflectance spectra (UV-vis DRS), photoluminescence (PL) spectra, transient photocurrent spectra, electron paramagnetic resonance (EPR) measurements and photocatalytic experiments, a suggested mechanism for the charge generation and transfer in the 3DOM TiO2@nanosheet SnS2 heterojunction was proposed. The improved charge separation and enhanced photocatalytic activity for the as-prepared TiO2@SnS2 composition can be attributed to the well-defined 3DOM heterojunction structure and the spatial transfer of the visible-light excited high energy electrons of SnS2 to TiO2. This work will provide a novel route to prepare highly active heterojunction photocatalysts and a new insight into the study of electron migration paths in TiO2@SnS2 composites.

Ni foam supported Co 3 O 4 nanoflakes is prepared for battery-type supercapacitor application through a simple three-step route. In briefly, Co metals are first deposited on Ni foam with a nanosheet morphology. The CoC 2 O 4 protrudes out from the surface of Co through an in-situ reaction with H 2 C 2 O 4 to form dendritic-like nanowires morphology. Finally, Co 3 O 4 are obtained through thermal decomposition of the CoC 2 O 4 precursor and the dendritic-like nanowires morphology is melting and transforming into a nanoflakes morphology. The unique architectures morphology with porosity and interconnected channels has great advantages since it can effectively increases the contact surface area with electrolyte, which could significantly not only enhances surface area but also the ion/electron diffusion. Electrochemical tests show that Co 3 O 4 nanoflakes exhibit a high specific capacity up to 576.8 C g − 1 at a current density of 1 A g − 1 and remain 283.7 C g − 1 capacity at a high current density of 50 A g − 1 , as well as 82% capacitance retained after 5000 cycles. These above results demonstrate the great potential of Co 3 O 4 nanoflakes in the development of battery-type supercapacitors.

One-dimensional (1D) nanostructures have been identified as the most viable structures for high-performance supercapacitors from the view of high ion-accessible surface area and rapid electron transport path as well as excellent mechanical properties. Herein, we report a “stripping and cutting” strategy to produce 1D carbon nanobelts (CNB) from tofu with irregular structures through a molten salts assisted technique. It is a completely novel and green avenue for constructing 1D carbon materials from biomass, showing large commercial potential. The resultant CNB electrode delivers a high specific capacitance (262 F g−1 at 0.5 A g−1) and outstanding cycling stability with capacitance retention up to 102% after 10 000 continuous charging/discharging cycles. Additionally, a CNB//CNB symmetric supercapacitor and CNB//MnO2–CNB asymmetric supercapacitor are assembled and reach energy densities of 18.19 and 29.24 W h kg−1, respectively. Therefore, such a simple, one-pot and low-cost process may have great potential for preparing eco-friendly biomass-derived carbon materials for high-performance supercapacitor electrodes.

A three-dimensional (3D) catalyst electrode of Co3O4 nanosheets in situ formed on reduced graphene oxide modified Ni foam (Co3O4/rGO@Ni foam) for H2O2 electroreduction is prepared by a two-step hydrothermal method. In the first step, graphene oxide sheets are reduced and formed on the skeleton of Ni foam and Co3O4 nanosheets are synthesized intermixed with the rGO sheets through the second step. The Co3O4 nanosheets are made up of plentiful nanoparticles and there are many nanoholes among these nanoparticles which are beneficial for the sufficient contact between H2O2 and the catalyst. The morphology and phase composition of the Co3O4/rGO@Ni foam electrode are studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrocatalytic activity of the as-prepared electrode is investigated by cyclic voltammetry (CV) and chronoamperometry (CA). From the results, it can be seen that in 2 mol L−1 NaOH and 0.5 mol L−1 H2O2, the reduction current density of H2O2 on the Co3O4/rGO@Ni foam electrode is 450 mA cm−2 at −0.8 V which is much higher than that on Co3O4 directly supported on Ni foam. This obvious increase of the current density can be attributed to the increase of the surface area of the electrode after the addition of rGO. Also, the interpenetration of rGO and Co3O4 nanosheets improves the electron and ion transport ability of the electrode which leads to a good electrocatalytic activity and stability of the Co3O4/rGO@Ni foam electrode.

A highly sensitive electrochemical sensor for the detection of ascorbic acid (AA) was first fabricated using network-like carbon nanosheets (NCN) as an enhanced electrode modifier. Novel carbon nanosheets were synthesized from willow catkin via a high temperature carbonization and chemical activation process with the aid of potassium hydroxide (KOH). The formation of porous and interconnected structures of the resulting product was characterized by various experiment techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and nitrogen isothermal adsorption–desorption technique. The network-like carbon nanosheet modified glassy carbon electrode (NCN/GCE) exhibited excellent electrocatalytic activity for the electrochemical oxidation of ascorbic acid owing to the unique network-like and partially graphitic structure. The amperometric curve of AA on the NCN/GCE showed a quick current response, a fine linear consistency of the peak current with the concentration of AA, a low detection limit and an excellent selectivity. Based on these excellent properties, a new sensing platform was developed and verified by the determination of ascorbic acid in commercial injections.

In our work, we successfully design boron (B) and nitrogen (N) co-doped porous carbon tube bundle (B/N-PCTB) electrode materials which are directly derived from the biomass of dandelion fluff. The low-tortuosity, and open and porous structures contribute to electron transport along the tube wall and unimpeded ion diffusion inside the carbon tubes. The incorporation of heteroatoms into PCTBs can bring extra pseudocapacitance and double layer capacitance to enhance the overall capacitance. Benefiting from the hollow and open microstructure and heteroatom doping, the optimized B/N-PCTB electrode (active materials: 2.6 mg cm−2) possesses an impressive specific capacitance of 355 F g−1 at 1 A g−1. Even with an ultrahigh loading mass of 40 mg cm−2, the electrode still has a relatively high specific capacity of 216 F g−1 at 1 A g−1. The assembled symmetric cell with an active material loading of 80 mg cm−2 (cathode: 40 mg cm−2; anode: 40 mg cm−2) shows a superior volumetric energy density of 12.15 W h L−1 at the power density of 699.84 W L−1. The facile yet high-performance porous carbon tube bundle is a promising material which can be applied in many other fields such as lithium ion batteries, hydrogen evolution reaction, and heavy metal ion adsorption.

Senna tora has been used as a famous traditional medicine both in China and India to treat skin diseases, cough, hepatitis, fever, and hemorrhoids. Here, the complete chloroplast (cp) genome sequen...

The supreme mechanical performance of natural rubber (NR) is commonly attributed to strain-induced crystallization (SIC). The SIC of NR during uniaxial stretch has been extensively investigated, whereas that under multiaxial deformation has been rarely reported, which is close to real service conditions (i.e., tire). In this work, the crystallization behavior of NR under biaxial stretch was studied with in situ synchrotron radiation wide-angle X-ray diffraction in combination with a custom-built biaxial stretch machine. It is observed that biaxial stretch frustrates the SIC of NR: within λ

Metallic anodes have high theoretical specific capacities and low electrochemical potentials. However, short-circuit problems caused by dendritic deposition and low Coulombic efficiency limit the cyclic life and safety of metallic anode-based batteries. Herein, dendrite-free and flexible three-dimensional (3D) alkali anodes (Li/Na-Ti

The role of definitive radiotherapy (dRT) and debulking surgery (DS) for patients with locally advanced, unresectable, Masaoka-Koga stage III thymomas was not well studied. Unresectable tumor refers to tumor that could not be completely resected because of invasion of surrounding organs. Consecutive patients with unresectable stage III thymomas between 2000 and 2017 were reviewed. According to the treatment intent and radiation dose, patients were categorized into a dRT group and a non-dRT group. The former group included patients who received radiotherapy at doses ≥ 54 Gy after DS or biopsy. The latter group included patients who did not receive radiotherapy and those who received a radiation dose

Molybdenum disulfide (MoS

Herein, we choose the waste walnut shell as the carbon source, and ammonium heptamolybdate as the molybdenum source to prepare the β-Mo

International audience; Computations of low-rank approximations of tensors often involve path-following optimization algorithms. In such cases, a correct solution may only be found if there exists a continuous path connecting the initial point to a desired solution. We will investigate the existence of such a path in sets of low-rank tensors for various notions of ranks, including tensor rank, border rank, multilinear rank, and their counterparts for symmetric tensors.

A three-dimensional free-standing hard carbon (FHC) electrode is synthesized by carbonizing the hemp haulm and employed as anode for sodium-ion batteries directly. A high current charging-discharging process is carried out to reconstruct surface structure of the FHC. Surface reconstructed FHC display a high capacity of 256 mAh/g and enhanced rate ability. With the formation of order surface structure, the plateau capacity increase and more sodium ions can insert into the FHC. This work demonstrates the importance of surface structure for sodium ion diffusion and storage and provide a new strategy to design high-performance anode materials.

A flag is a sequence of nested subspaces. Flags are ubiquitous in numerical analysis, arising in finite elements, multigrid, spectral, and pseudospectral methods for numerical PDE; they arise in the form of Krylov subspaces in matrix computations, and as multiresolution analysis in wavelets constructions. They are common in statistics too --- principal component, canonical correlation, and correspondence analyses may all be viewed as methods for extracting flags from a data set. The main goal of this article is to develop the tools needed for optimizing over a set of flags, which is a smooth manifold called the flag manifold, and it contains the Grassmannian as the simplest special case. We will derive closed-form analytic expressions for various differential geometric objects required for Riemannian optimization algorithms on the flag manifold; introducing various systems of extrinsic coordinates that allow us to parameterize points, metrics, tangent spaces, geodesics, distance, parallel transport, gradients, Hessians in terms of matrices and matrix operations; and thereby permitting us to formulate steepest descent, conjugate gradient, and Newton algorithms on the flag manifold using only standard numerical linear algebra., 27 pages, 2 figures

Background: Growing evidence indicates that several inflammatory biomarkers may predict survival in patients with malignant tumors. The aim of this study is to evaluate the prognostic value of pretreatment biomarkers in patients with primary small-cell carcinoma of the esophagus（PSCCE）. Methods: There were 73 PSCCE patients enrolled between January 2009 and December 2017 at the Affiliated Cancer Hospital of Zhengzhou University. The total lymphocyte counts (TLC), neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) prior to anticancer therapy were collected as inflammation biomarkers. The cut-off value was determined by Receiver operating characteristic (ROC). The Kaplan–Meier method was utilized to analysis overall survival (OS). Cox proportional hazards regression was used to identify univariate and multivariate prognostic factors. Results: Univariate analysis showed that high NLR group(hazard ratio (HR) ＝1.685; 95% CI: 1.001–2.838; P＝0.047) and high PLR group (hazard ratio (HR) ＝1.716; 95% CI: 1.039–2.834; P＝0.033) were associated with poor OS, and TLC was not correlated with OS. On multivariate analysis, high PLR(hazard ratio (HR) ＝1.751; 95% CI: 1.042–2.945; P＝0.035) was an independent prognostic factor of unfavorable OS. Conclusions: Pre-treatment PLR and NLR are correlated with OS. These biomarkers are easily accessible, cost effective, and can serve as a marker to identify high-risk patients for further designing personalized treatment and predicting treatment outcomes.

A fast one-step arc discharge exfoliation method is employed to synthesize Si/graphene composites by using a graphite rod filled with a mixture of Si powder and urea as a cathode. During the arc discharge process, the use of urea allows both the introduction of nitrogen atoms into the graphene and the uniform sealing of Si nanoparticles between the thin graphene sheets to occur simultaneously. The resulting N-doped graphene nanosheets embedded with Si (Si@NG) can act as an electrode material for lithium-ion batteries and delivers the reversible capacity of 1030 mAh g-1 with a current density of 200 mA g-1 over 100 cycles along with an outstanding coulombic efficiency of 96.84 %. The remarkable electrochemical rate capability performance can be owed to the multiple role of NG, which not only serves as a three-dimensional conductive support, but also effectively limits the volume variation of Si nanoparticles. The approach proposed here is expected to be extended to the preparation of other alloy anode/graphene hybrids for lithium ion batteries.

Highlights Nitrogen and phosphorus dual-doped multilayer graphene (NPG) was prepared by arc discharge process.NPG exhibits good rate capability and stable cycling performance in both lithium and potassium ion batteries.Full carbon-based lithium/potassium ion capacitors are assembled and show excellent electrochemical performance. Electronic supplementary material The online version of this article (10.1007/s40820-019-0260-6) contains supplementary material, which is available to authorized users., Lithium/potassium ion capacitors (LICs/PICs) have been proposed to bridge the performance gap between high-energy batteries and high-power capacitors. However, their development is hindered by the choice, electrochemical performance, and preparation technique of the battery-type anode materials. Herein, a nitrogen and phosphorus dual-doped multilayer graphene (NPG) material is designed and synthesized through an arc discharge process, using low-cost graphite and solid nitrogen and phosphorus sources. When employed as the anode material, NPG exhibits high capacity, remarkable rate capability, and stable cycling performance in both lithium and potassium ion batteries. This excellent electrochemical performance is ascribed to the synergistic effect of nitrogen and phosphorus doping, which enhances the electrochemical conductivity, provides a higher number of ion storage sites, and leads to increased interlayer spacing. Full carbon-based NPG‖LiPF6‖active carbon (AC) LICs and NPG‖KPF6‖AC PICs are assembled and show excellent electrochemical performance, with competitive energy and power densities. This work provides a route for the large-scale production of dual-doped graphene as a universal anode material for high-performance alkali ion batteries and capacitors. Electronic supplementary material The online version of this article (10.1007/s40820-019-0260-6) contains supplementary material, which is available to authorized users.

Shape memory effect (SME) is a quite novel and interesting phenomenon to all kinds of materials, though the working mechanism of SME in different materials may be distinct to each other. Three different mechanisms, consisting of dual-state, dual-component and partial-transition are the main reasons that lead to shape memory effect in almost all metals, ceramics, polymers and composites, whether they work on the materials individually or jointly. Shape memory polymers are favorable materials for ergonomics such as comfort fitting clothes and footwear because of its manual programmability instead of using a heavy machine to do the programming. Therefore, to make use of the shape memory effects, different design and synthesis methodologies are adopted to investigate how well the SME can achieve. In this thesis, a commercially available polymeric material, styrene-butadiene-styrene block copolymer (thermo-plastic rubber, TPR) pellets are manufactured into thin films to thoroughly investigate its mechanical response and shape memory effect. The elasticity and ductility of TPR are considerably good under room temperature, but not the shape memory effect such that the laminate composite is proposed to improve it. Finally, alternative method to fabricate TPR thin film is proposed to eliminate the problem of anisotropy and residual stress. But this method is hazardous to environmental and health such that it is not suitable for mass production. Master of Science (Mechanical Engineering)

Background: Microvascular invasion (MVI) is a critical prognostic factor for operable hepatocellular carcinoma (HCC). This study aimed to explore the performance of circulating tumor DNA (ctDNA) in evaluating MVI status preoperatively. Methods: Forty-nine HCC patients were enrolled and clinicopathological characteristics were collected. Preoperative blood and surgical tissue samples were obtained, and genomic alterations were analyzed using targeted deep sequencing with a 1021-gene panel. Findings: Totally 260 somatic mutations were identified in 40 blood samples (81*6%). The most recurrent mutant genes included TP53 (55*1%), TERT (16*3%), AXIN1 (12*2%), LRP1B (10*2%) and CTNNB1 (10*2%). CtDNA mutation was verified in paired tissue sample in 39 patients (97*5%). In univariate analysis, ctDNA allele frequency (AF) and largest tumor diameter were associated with the presence of MVI, but ctDNA AF was the only independent risk factor in multivariate analysis. With the cut-off value of 0*83%, ctDNA AF determined the presence of MVI with the sensitivity of 89*7% and specificity of 80*0%. Although MVI status, ctDNA AF, AFP level, Edmondson-Steiner classification and BCLC staging were associated with recurrence-free survival, MVI was the most powerful and significant prognostic factor in Cox regression analysis. Interpretation: CtDNA can serve as an independent risk factor of MVI for operable HCC and help deciding precise treatment strategies and ultimately better clinical outcomes. Funding Statement: This study was funded by the National Nature Science Foundation of China (No. 81771932) and Tianqing Liver Disease Research Fund of the China Hepatitis Prevention Foundation (No. TQGB20180120). Declaration of Interests: The authors declare no any potential competing interest. Ethics Approval Statement: All patients provided written informed consent. The study was approved by the Ethics Committee of Xiangya Hospital affiliated to Central South University (No. 201703377).

Potassium-ion batteries (PIBs) have huge advantages in terms of price and resource abundance, and are ideal substitutes for lithium-ion batteries (LIBs), but there is currently little research on their high-temperature fields. In this work, the sulfur-doped biomass carbon (CHP/S) is synthesized from biomass hemp stalks as the carbon source and sulfur powder as the sulfur source, with a high sulfur content of 18.6%. Sulfur mainly exist in the form of bonded sulfur (S-C, S-O) and have quite favorable stability. As a PIBs anode, it exhibits a specific capacity of 589 mAh g−1 (30 mA g−1) at 60 °C, which is 1.5 times the capacity at 25 °C. Electrochemical analysis and kinetic analysis indicate that the increased capacity mainly comes from the “arousal effect” of sulfur under high temperature conditions, and an increased temperature has a positive effect on the absorption and desorption performance of the material. In addition, the full cell assembled with Perylene-3, 4, 9, 10-tetracarboxylic dianhydride (PTCDA) cathode shows greater capacity (~80 mAh g−1) at 60 °C than at 25 °C. Unfortunately, the electrolyte decomposition problem caused by high temperature is easily dangerous. The result is of great significance to the research of high-temperature PIBs.

Metal–organic frameworks (MOFs) derivatives are excellent electrocatalytic materials due to their own structural characteristics. However, it is still very essential to design a logical synthesis route of MOFs derivatives to avoid the adverse effects caused by the collapse of MOFs structure and improve its intrinsic catalytic activity. For these reasons, we designed and synthesized cobalt-based metal-organic framework (ZIF67) grown in situ at the edge of Co(OH)2 nanosheets. Through adjusting the alcohol-water ratio of the reaction solution, the number of ZIF67 grown on the Co(OH)2 can be controlled to make it grow uniformly at the edge of nanosheet. After the selenization reaction in a tube furnace, ZIF67 is transformed into CoSe2 (Co-Z/Se-2) with a yolk-shell structure. This precisely designed synthetic route allows Co-Z/Se-2 to expose more active sites, which is conducive to electron transport and has good performance in both urea oxidation reaction (UOR) and hydrogen evolution reaction (HER). Co-Z/Se-2 as UOR catalyst only needs 1.390 V to reach 50 mA cm−2. Co-Z/Se-2 as bifunctional catalysts, are assembled to be a urea electrolyzer cell. Co-Z/Se-2 || Co-Z/Se-2 only needs 1.490 V to drive 10 mA cm−2, and can maintain a good stability for 20 h.

Ethnopharmacological relevance Xian-He-Cao-Chang-Yan formula (XHCF) is consisting of six crude drugs including Agrimoniae Herba, Coptidis Rhizoma, Aucklandiae Radix, Cicadae Periostracum, Acori Tatarinowii Rhizoma, and Platycodonis Radix at the ratio of 5:1.5:1.5:1.5:1.5:1. It has been used to improve syndromes of ulcerative colitis (UC) for many years. Aim of the study This study was designed to study the bioactive ingredients and therapeutic mechanisms of XHCF. Materials and methods The chemical profile of XHCF was characterized by UHPLC-QTOF-MS/MS. The effects and mechanisms of XHCF on UC were investigated in colitis mice induced by dextran sulfate sodium (DSS) and LPS-stimulated RAW 264.7 cells. Results A total of 103 compounds were characterized in XHCF. XHCF could effectively improve acute colitis induced by DSS. More importantly, XHCF significantly decreased M1 macrophage markers (CD11c, IL-6 and IL-1β) whereas increased M2 macrophage markers (CD206) in colitis mice, suggesting it could regulate macrophage polarization. Furthermore, the levels of HK2 and lactic acid in colon tissues were significantly reduced by XHCF, indicating that XHCF could inhibit glycolysis. It also down-regulated HK2 expression in macrophages challenged by LPS. In addition, XHCF enhanced the phosphorylation of AMPK both in vivo and in vitro, suggesting the involvement of AMPK in XHCF function. Conclusions XHCF ameliorated DSS-induced colitis in mice via inhibition of M1 macrophage polarization, probably by the modulation of macrophage metabolic reprogramming via AMPK, contributing to its anti-inflammatory activity. The synergistic actions of multiple ingredients might be responsible for the therapeutic benefits of XHCF on UC.

LiVO3 is prepared by the combustion method and applied as anode material for rechargeable lithium-ion batteries. The LiVO3 electrode material shows excellent electrochemical performance in the voltage window of 0.2-3V. It displays a high specific capacity and capable capacity retention. Moreover, a full vanadium-based cell is designed based on the LiVO3 anode and Li3V2(PO4)3 cathode. The full cell presents a stable cycling performance and good rate ability. This work suggests a potential vanadium-based anode material and the possibility of the full vanadium-based cell.

The composites composed of metal selenides and carbonaceous materials have revealed enormous potential in varied applications. Herein, CoSe2/reduced graphene oxide (CoSe2/RGO) composites are prepared by a low-cost and efficient microwave assisted method. The effects of RGO proportion on crystalline structure, microstructure and energy storage capacity are explored. Benefiting from the good electrical conductivity and reasonable RGO content, the CoSe2/RGO sample with 35.2 wt% RGO reveals an excellent specific capacitance of 761 F g−1 as well as outstanding durability. More importantly, we construct an all solid-state hybrid supercapacitor (CoSe2/RGO//active carbon) to broaden the voltage window, resulting in an enhanced energy density (43.1 Wh kg−1). The hybrid device presents a favorable durability with 10% capacity drop after 10,000 cycles. In addition, the practical applicability of asymmetric device is confirmed by powering a blue light emitting diode (LED) for more than 10 mins. This work presents a simple, effective, and reasonable construct strategy to synthesize composites of selenides and RGO for charge storage application.

Bimetallic metal selenides have gained increasing attention as potential electrode materials for energy storage systems owing to good electrical conductivity and superior electrochemical activity. Herein, the NixCoySe2 (x+y=1) electrodes are prepared by a facile and rapid electrodeposition process. The electrochemical performance is optimized via adjusting the ratio of Co and Ni. It is turned out that equivalent Co and Ni in the composite (Ni1/2Co1/2Se2) shows the best supercapacitor performance, including high specific capacity (166.1 mAh g−1) and long-term stability. Moreover, Density Functional Theory (DFT) calculation confirms the covalent interaction between nickel and cobalt, implying the existence of synergistic effect. To assess the practical value of the rationally designed Ni1/2Co1/2Se2 electrode material, an asymmetric supercapacitor device is fabricated (Ni1/2Co1/2Se2//AC), which delivers a high energy density of 46.0 Wh kg−1 at 1141 W kg−1, coupled with 9.8% capacity loss after 10000 cycles. Notably, the low-voltage setups (LED and electric fan) can be easily activated by two devices in series, further demonstrating the great potential for practical application of Ni1/2Co1/2Se2 electrode.

Thanks to their high electrical conductivity, electrochemical stability and activity, transition metal sulfides have been widely designed and developed for supercapacitors with excellent electrochemical performances. Herein, we report the NiS2/MoS2 mixed phases with abundant exposed active edge sites decorated on graphene nanosheets (named as (Ni,Mo)S2/G) through a facile two-step hydrothermal approach. Benefitting from its unique chemical property and structure, the as-prepared (Ni,Mo)S2/G composite possesses impressive electrochemical performances as electrodes of battery-type supercapacitors in 2 M KOH, such as high specific capacity of 951 C g−1 (2379 F g−1) at 1 A g−1 with superb rate capability (60.7% at 100 A g−1). Additionally, the asymmetric supercapacitor (ASC) device assembled based on the active edge site-enriched (Ni,Mo)S2/G as positive electrode and nitrogen-doped porous graphene as negative electrode displays an ultrahigh energy density of 84.5 Wh kg−1, superior to those of the Ni- and Mo-based ASCs in aqueous electrolytes reported so far. Such novel strategy may hold great promise for exploring other polymetallic sulfides with abundant exposed active edge sites for energy storage and conversion.

Aqueous batteries are appealing for large-scale storage applications, due to their high safety level, low cost, and excellent durability. In this study, we reported a new anode material, namely sulfur perylene-3,4,9,10-tetracarboxylate (PTC-S), which is more stable than other electrode materials used in aqueous Mg-Li ion batteries. When PTC-S is used as the anode in 0.5 M MgCl2 + 0.5 M LiCl with a current density of 50 mA g−1, the discharge specific capacity is 287.3 mAh g−1 at the initial cycle and the capacity retention rate is still close to 100% at over 1000 cycles. The monomer structural material conjugated with bifunctional groups can provide the space for the intercalation of Mg2+ and Li+ at the same time, shorten the ion transmission path and accelerate the transmission speed of metal ions in the electrode. In order to develop aqueous battery as quickly as possible, LiMn2O4 and PTC-S are used as cathode and anode materials, respectively, in a dual-ion salt aqueous battery. The PTC-S‖LiMn2O4 battery exhibits a high capacity and an excellent cycling stability performance in aqueous Mg-Li ion battery. The battery has a high capacity performance of 240.0 mAh g−1 at a voltage ranging from 0.0 V to 1.8 V, as well as a high specific energy density of 172.8 Wh kg−1 and remarkable cycling stability. PTC-S in 0.5 M MgCl2 electrolyte has a current density of 100 mA g−1, a specific discharge capacity of 203 mAh g−1 and a first-cycle Coulomb efficiency close to 100%. Under the same test conditions, the discharge specific capacity is higher than that of the perylene-3,4,9,10-tetracarboxylic dihydride (PTCI) electrode (101 mAh g−1), and the capacity retention rate is increased by 30.4%.

Potassium ion batteries (PIBs) have attracted lots of attention due to its abundant resources. Exploring capable anode materials becomes one of the critical issues to achieve high-performance PIBs. Herein, carbon-coated SnS nanosheets and reduced graphene oxide (SnS@C/rGO) composite are designed and synthesized by a solvothermal reaction and heat treatment. The strategy of double carbon modification enhances the rate performance of SnS. Meanwhile, the cycling stability of SnS@C/rGO can be further improved by optimizing the voltage window, which can achieve the potassiation stage adjustment. K ions storage mechanism of SnS@C/rGO is investigated under different voltage windows. The deep alloying reaction occurs under low potential and is harmful to cycling performance. Moreover, the electrochemical kinetics of K ions storage is investigated by quantitative kinetics analysis. This work highlights the important effect of dual-carbon modification and adjusting the potassiation stage on the K ion storage.

Flexible electrochemical energy storage devices have great potential in wearable and portable electronic devices. However, their practical applications have been deferred by mechanical damages such as repeated stretching, bending and squeezing. Self-healing hydrogel electrolytes can automatically repair such physical damages and maintain good electric contact at electrode/electrolyte interface. Herein, we report a hydrogel electrolyte with excellent tensile properties and good conductivity under large strain/stress. A solid state supercapacitor was further demonstrated, showing a high energy density of 21.3 Wh kg-1 at a power density of 350 W kg-1. The as-fabricated supercapacitor possesses good stretchability, with a 68% of retention of its initial capacitance after 40 breaking/healing cycles. The excellent self-healing capability of the hydrogel electrolyte can be attributed to the presence of hydrogen bonds and molecular chain fluidity within its structural motif. Our work provides promising routes towards developing new self-healing solid-state electrolytes for next-generation electrochemical energy storage and conversion applications with good performance and high safety.

This work presents a novel method for loading phosphorus nanoparticles by gas deposition. A large amount of nano phosphorus is loaded on the carbon matrix by the reaction of phosphine gas heating. The carbon is obtained by carbonization of hemp and has a natural porous structure. The combination of phosphorus and carbon in the form of C–O–P has better stability. The product obtained a stable capacity of 463 mAh/g at 0.04 A/g. There was still a reversible capacity of 270 mAh/g after continuous operation for 6 months at a high current density of 1 A/g, and the capacity retention rate was 96.7%. The excellent cyclic stability is due to new methods of phosphorus deposition. It can reach 10 times the running time of the same type of battery, which provides a new idea for preparing phosphor-doped electrode materials. Assembled into a potassium ion capacitor, an energy density of 294.2 Wh/kg can be obtained.

To improve the structure stability and accelerate electrochemical reaction kinetics, oxygen vacancies-enriched sub-7 nm Bi2.88Fe5O12-x nanoparticles with high electrochemical activity have been elaborately anchored on two-dimensional MXene nanosheets through a facile electrostatic assembly approach for electrochemical energy storage. MXene nanosheets could not only effectively buffer the serious volume change of Bi2.88Fe5O12-x nanoparticles but also facilitate fast electron transfer as a flexible, well-conductive but robust substrate in the fast charge/discharge processes. Owing to the three-dimensional distinct structure and the strong synergistic effects between MXene and Bi2.88Fe5O12-x nanoparticles, the obtained composite exhibits impressive electrochemical performances. The composite electrode possesses high gravimetric specific capacity of 176 mAh g−1 with ultrahigh volumetric specific capacity of 476 mAh cm−3 at 0.5 A g−1 in an aqueous electrolyte, superior to those of the so-far reported Bi2O3-based electrode materials. In addition, our fabricated asymmetric device displays a high volumetric energy density of 177 Wh L−1 and remarkable cycling performance with 93.3% retention ratio after 10,000 cycles. Moreover, the resultant MXene/Bi2.88Fe5O12-x composite presents high reversible specific capacity of 805 mAh g−1 for Li-ion storage, corresponding to the volumetric specific capacity of 2176 mAh cm−‍3.

Searching for anode materials with fast Li+ intercalation kinetics to mitigate the dynamic imbalance with the rapid capacitive cathode is the fundamental strategy to achieve high energy-power density of Li-ion capacitors (LICs). Hence, NiNb2O6 hollow nanoparticles are first synthesized by hydrothermal method and then sealed with a protective N-doped carbon shell to achieve the target NiNb2O6@NC composite. As the anode of LICs, the NiNb2O6@NC sample exhibits a high capacity of 435.8 mAh g−1 at 50 mA g−1 and excellent rate performance of 47.8% capacity retention with the current density increased to 2 A g−1. The lithium storage mechanism of NiNb2O6 is proposed as a combined conversion reaction and an intercalation reaction, which the NiNb2O6 decomposes into Ni metal and LixNb2O5 during the 1st discharge/charge process. The irreversible Ni would not contribute to the reversible capacity and will improve the electric conductivity for fast transport of electrons and the LixNb2O5 will act as the host for lithium ions by means of the intercalation mechanism. Furthermore, the assembled NiNb2O6@NC//activated carbon LICs exhibit a maximum energy density of 123.9 Wh kg−1 and the capacity retention reaches 86.1% after 5000 cycles. The superior electrochemical performances indicate that the rationally-designed NiNb2O6@NC is expected to be a potential anode material for LICs.

A previously undescribed polyketide (1) and 3 known analogs (2-4) were obtained from cultures of the potato endophytic fungus Aspergillus carneus. The structures were elucidated on the basis of extensive nuclear magnetic resonance spectroscopic data. The absolute configuration of 1 was further determined by electronic circular dichroism and optical rotation calculations. Compounds 1-4 showed moderate antifungal activity against plant pathogens. Compounds 1, 2, and 4 inhibited nitric oxide production in lipopolysaccharide-stimulated RAW264.7 cells, with half-maximal inhibitory concentration values of 13.36, 30.16, and 51.47 µM, respectively. Compound 4 showed effective antioxidant activity.

In this work, hierarchically mesoporous silica (HMS) microspheres with ordered mesochannels and ultra-large intra-particulate pores are for the first time prepared via a ternary nonionic surfactant templating system (TEOS/P123/HCl(aq.)). Several crucial experimental parameters pertaining to the employed partitioned cooperative self-assembly process and their roles in shaping the mesostructures and morphology were investigated. It was found that relatively low synthesis temperatures, optimal at 36 °C, lead to much improved meso-ordering in the 1st mode mesostructures, while partitioned addition combinations of silica precursor ( e.g. , 6/4 combination) at such temperatures show to play an important role in inducing spherical particle morphology. By simply increasing the hydrothermal treatment (HTT) temperature up to 140 °C, enhanced porosity together with ultra-large intra-particulate pores can be obtained without compromising meso-orderings, depending mainly on the HTT induced mesostructural transformation process. Higher HTT temperature causes the fragmentation in the 1st mode mesostructures and disappearance of meso-orderings. The resultant micro-sized HMS spheres reveal certain clew-like features: the ‘yarns’ comprise bundles of ordered mesochannels (1st mode mesopores, ca. 8–12 nm), while the 2nd mode intra-particulate pores ( ca. 33–128 nm in sizes) exist between the intertwined ‘yarns’. Such HMS microspheres with tunable porous structures might find some interesting applications in chromatographic separations and controlled delivery, etc.

For the first time, hierarchically porous carbon materials with a sandwich-like structure are synthesized through a facile and efficient tri-template approach. The hierarchically porous microstructures consist of abundant macropores and numerous micropores embedded into the crosslinked mesoporous walls. As a result, the obtained carbon material with a unique sandwich-like structure has a relatively high specific surface (1235 m2 g−1), large pore volume (1.30 cm3 g−1), and appropriate pore size distribution. These merits lead to a comparably high specific capacitance of 274.8 F g−1 at 0.2 A g−1 and satisfying rate performance (87.7 % retention from 1 to 20 A g−1). More importantly, the symmetric supercapacitor with two identical as-prepared carbon samples shows a superior energy density of 18.47 Wh kg−1 at a power density of 179.9 W kg−1. The asymmetric supercapacitor based on as-obtained carbon sample and its composite with manganese dioxide (MnO2) can reach up to an energy density of 25.93 Wh kg−1 at a power density of 199.9 W kg−1. Therefore, these unique carbon material open a promising prospect for future development and utilization in the field of energy storage.

Facile in-situ etching current collector prepares corresponding oxide or sulfide, which is directly used as faradic electrode material, supplying faster electron transportation and better connection, and thus displaying good supercapacitor performance. Here, we prepare Cu x S via etching copper foam and investigate the influence of etching time on the morphology and electrochemical performance. The results show that compared with the nano-rod Cu x S-1h/CF, nano-rod/wire Cu x S-2h/CF and block/nanorod Cu x S-4h/CF, the nano-rod/ribbon Cu x S-3h/CF electrode exhibits the highest specific capacity (448.8C g −1 at current density of 5 mA cm −2 ). We fabricate asymmetric supercapacitor based on Cu x S-3h/CF as positive electrode and AC as negative electrode to further evaluate the supercapacitor property and the device achieves a high energy density of 35 Wh kg −1 at power density of 266 W kg −1 . Furthermore, the outstanding cycling stability of 88% capacitance retention after 5000 charge-discharge cycles more enable the Cu x S-3h/CF become promising faradic electrode material.

We discuss a generalization of the Cohn---Umans method, a potent technique developed for studying the bilinear complexity of matrix multiplication by embedding matrices into an appropriate group algebra. We investigate how the Cohn---Umans method may be used for bilinear operations other than matrix multiplication, with algebras other than group algebras, and we relate it to Strassen's tensor rank approach, the traditional framework for investigating bilinear complexity. To demonstrate the utility of the generalized method, we apply it to find the fastest algorithms for forming structured matrix---vector product, the basic operation underlying iterative algorithms for structured matrices. The structures we study include Toeplitz, Hankel, circulant, symmetric, skew-symmetric, f-circulant, block Toeplitz---Toeplitz block, triangular Toeplitz matrices, Toeplitz-plus-Hankel, sparse/banded/triangular. Except for the case of skew-symmetric matrices, for which we have only upper bounds, the algorithms derived using the generalized Cohn---Umans method in all other instances are the fastest possible in the sense of having minimum bilinear complexity. We also apply this framework to a few other bilinear operations including matrix---matrix, commutator, simultaneous matrix products, and briefly discuss the relation between tensor nuclear norm and numerical stability.

In this paper, we employed the as-prepared TiO2/C core/shell nanoarrays (TiO2/C) obtained by a facile thermal evaporation method as a three-dimensional (3D) architecture to support Pt nanoparticles through an optimized electrodeposition process. The morphology and structure of the as-prepared electrode are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Its catalytic performance towards H2O2 electroreduction in basic medium is evaluated by linear sweep voltammetry (LSV) and chronoamperometry (CV). Results revealed that the electrode exhibits significantly high catalytic activity. The current density reached –0.172 A cm−2 in 1 mol dm−3 NaOH and 0.5 mol dm−3 H2O2 at –1.1 V (vs. Ag/AgCl). This high performance might be due to the 3D electrode architecture inheriting the high electronic conductivity from carbon shell and providing a short pathway for the ion diffusion, and the using of Pt owning an excellent catalytic activity.

A facile hydrothermal synthetic method, followed by in situ reduction and galvanic replacement processes, is used to prepare PtCo-modified Co3O4 nanosheets (PtCo/Co3O4 NSs) supported on Ni foam. The prepared nanomaterial is used as an electrocatalyst for NaBH4 oxidation in alkaline solution. The morphology and phase composition of PtCo/Co3O4 NSs are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The catalytic performance of PtCo/Co3O4 NSs is investigated by cyclic voltammetry (CV) and chronoamperometry (CA) in a standard three-electrode system. Current densities of 70 and 850 mA·cm–2 were obtained at–0.4 V for Co/Co3O4 and PtCo/Co3O4 NSs, respectively, in a solution containing 2 mol·L–1 NaOH and 0.2 mol·L–1 NaBH4. The use of a noble metal (Pt) greatly enhances the catalytic activity of the transition metal (Co) and Co3O4. Besides, both Co and Co3O4 exhibit good B–H bond breaking ability (in NaBH4), which leads to better electrocatalytic activity and stability of PtCo/Co3O4 NSs in NaBH4 electrooxidation compared to pure Pt. The results demonstrate that the as-prepared PtCo/Co3O4 NSs can be a promising electrocatalyst for borohydride oxidation.

Urea electro-oxidation reaction in alkaline medium is systematically analyzed by electrochemical impedance spectroscopy (EIS). The effects of polarization potential and KOH concentration on the impedance appearance are investigated. In the presence of urea, it is found that Nyquist plots exhibit two depressed semicircles, with one at higher frequencies stably locating in the first quadrant while the other’s location at lower frequencies varying between the first and second quadrant as the polarization potential changes. Results show both indirect and direct pathways proceed in urea electro-oxidation reaction. A mathematical model indicates the reverse loop in the Nyquist plots is attributed to CO 2 poisoning on the catalyst, which is also validated by the followed chronoamperometric method. Moreover, the rate determining steps of urea electro-oxidation reaction is dependent on KOH concentration. The EIS technique gives a new sight to interpret the poor stability of urea electro-oxidation on nickel catalyst, and thus helps to explore a CO 2 -insensitive catalyst.

Three-dimensional (3D) reduced graphene networks (RGN) were successfully fabricated on Ni foam without any conductive agents and polymer binders by dipping commercial Ni foam into graphene oxide (GO) suspension and subsequent a electroreduction process in a buffer solution. Au nanoparticles were then deposited on the RGN through an electrodeposition process to form a novel reduced graphene networks-Au (RGNA) electrode. The morphology and phase structure of the RGNA electrode are characterized by scanning electron microscope, transmission electron microscope and X-ray diffraction spectrometer. The NaBH 4 electrooxidation performance on the RGNA electrode is investigated by means of cyclic voltammetry and chronoamperometry. The RGNA electrode owns special hierarchical porous structure, rapid electron and ion transport, and large electroactive surface area due to the intrinsic electronic conductivity, mesoporous nature of graphene. The RGNA electrode exhibits a good stability during the electrochemical process and the oxidation current density at RGNA electrode reached 500 mA cm −2 at 0 V in the solution containing 0.1 mol dm −3 NaBH 4 and 2 mol dm −3 NaOH, which is higher than that at bare Au–Ni foam without graphene. The excellent structural stability and high catalytic performance for NaBH 4 electrooxidation make the RGNA a promising material for future energy systems.

A novel three-dimensional (3D) porous nickel-cobalt (Ni-Co) film on nickel foam is successfully prepared and further used as an efficient anode for direct urea-hydrogen peroxide fuel cell (DUHPFC). By varying the cobalt/nickel mole ratios into 0%, 20%, 50%, 80% and 100%, the optimized Ni-Co/Ni foam anode with a ratio of 80% is obtained in terms of the best cell performance among five anodes. Effects of the KOH and urea concentrations, the flow rate and operation temperature on the fuel cell performance are investigated. Results show DUHPFC with the 3D Ni-Co/Ni foam anode exhibits a higher performance than those reported direct urea fuel cells. The cell gives an open circuit voltage of 0.83 V and a peak power density as high as 17.4 and 31.5 mW cm−2 at 20 °C and 70 °C, respectively, when operating on 7.0 mol L−1 KOH and 0.5 mol L−1 urea as the fuel at a flow rate of 15 mL min−1. Besides, when the human urine is directly fed as the fuel, direct urine-hydrogen peroxide fuel cell reaches a maximum power density of 7.5 mW cm−2 with an open circuit voltage of 0.80 V at 20 °C, showing a good application prospect in wastewater treatment.

This work demonstrates that based on a simple improved ternary nonionic surfactant templating system, hierarchically meso-mesoporous (HMM) silicas with ultra-large pores and pore volumes can be facilely prepared by combining hydrothermal treatments (HTT) with the partitioned cooperative self-assembly (PCSA) process. The obtained clew-like HMM silica particles contain bimodal pore size distributions. The disordered 1st mode mesostructures (pore sizes of 7–20 nm) form the ‘yarns’, while the 3D-interconnected 2nd mode intra-particulate pores (33–118 nm in sizes) exist between the ‘yarns’. The ultra-large pore volume reaching 3.22 cm 3 g −1 can be achieved. The formation of such HMM silicas arises from the HTT induced fragmentation of the 1st mode mesostructures.

Considering the good ability of MnO2 for the breakage of the HO–OH bond in H2O2, we employed C@TiO2 nanowire supported MnO2 as a novel catalyst for H2O2 electroreduction. The morphology and phase structure of the MnO2/C@TiO2 electrode are characterized by scanning electron microscopy, transmission electron microscopy and X-ray diffractometry. The catalytic activity of the MnO2/C@TiO2 electrode for H2O2 electroreduction is investigated by means of cyclic voltammetry and chronoamperometry. The catalyst exhibits a high catalytic activity and good stability in the electrochemical reaction process. The oxidation current density is higher than 200 mA cm−2 at −0.7 V in 1.6 mol dm−3 H2O2. The popular price, abundant reserves, and promising electrocatalytic performance make it a viable catalyst for H2O2 electroreduction.