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A facile “carbon quantum dots glue” strategy for the fabrication of honeycomb-like carbon quantum dots/nickel sulphide network arrays on Ni foam surface is successfully demonstrated. This design realizes the immobilization of nanosheet arrays and maintains a strong adhesion to the collector, forming a three-dimensional (3D) honeycomb-like architecture. Thanks to the unique structural advantages, the resulting bind-free electrode with high active mass loading of 6.16 mg cm−2 still exhibits a superior specific capacitance of 1130F g−1 at 2 A g−1, and maintains 80% of the initial capacitance even at 10 A g−1 after 3000 cycles. Furthermore, the assembled asymmetrical supercapacitor delivers an energy density of 18.8 Wh kg−1 at a power density of 134 W kg−1, and outstanding cycling stability (100% of initial capacitance retention after 5000 cycles at 5 mA cm−2). These impressive results indicate a new perspective to design various binder-free electrodes for electrochemical energy storage devices.

Heteroatoms doped carbon nanotubes are prepared through a solid-state pyrolytic conversion strategy with low-cost and easy-to-get precursors. The use of inorganic sulfur source makes it possible for sulfur to be effectively introduced, which is found to increase the defective degree in the carbon plane. The defect augment is revealed by systematic physical characterizations to originate from the fact that S atoms get rid of the carbon crystal and diffuse to form bits of sulfides during the heat-treatment process, thus leaving abundant vacant spots and providing access to forming pyridine-N sites. Therefore, more catalytic active sites are exposed and the oxygen reduction reaction (ORR) activity can be improved. Benefiting from the advantages in structure and composition, the resultant catalyst shows a remarkable half-wave potential (0.86 V vs. RHE) and an outstanding durability, superior to that of Pt/C. The zinc-air battery with the resultant catalyst shows high peak power density and excellent rate capability. This work not only develops a facile method to prepare highly active and stable ORR catalyst but also makes deep researches on the activity-enhanced mechanism.

Supercapacitors (SCs) are drawing considerable attention because of their remarkable power density, long cycling stability, quick charging/discharging, and environmentally friendly characteristics. They are currently applied in electronic devices and wearable energy storage systems. Recently, the use of asymmetric supercapacitors (ASCs) has been acknowledged as a valid strategy to improve energy density of SCs due to the combination of electric double-layered anodes and redox-schemed cathodes. Here, mesoporous hollow NiCo2S4 sub-microspheres and porous graphene/single-walled carbon nanotubes are synthesized by a simple and elegant method without any use of templates. The as-synthesized products exhibit improved capacitive performance and extraordinary stability. An assembled asymmetric supercapacitor with graphene/single-walled carbon nanotubes and NiCo2S4 as its negative and positive electrodes, respectively, delivers a maximum energy density of 45.3 W h kg−1 (at 800 W kg−1) and an outstanding cycling life (87.5% over 20,000 cycles). This suggests that the obtained products possess huge potential to become the next generation of electrode materials for future energy storage devices.

In this study, a bismuth ferrite (BiFeO3) nanopowder was synthesized by combining Bi(NO3)3·5H2O, Fe(NO3)3·9H2O, and NaOH raw materials in the presence of polyethylene glycol (PEG) with varying polymerization degrees (i.e. PEG200, PEG400, PEG600, and PEG10000). The synthesis process was carried out by room-temperature solid-state reaction followed by subsequent secondary solid-state reaction at 550 °C. The results suggested a significant influence of PEG polymerization degree on the morphology and size of the as-synthesized products. The grain size decreased after the introduction of PEG but increased with the polymerization degree. The vibrating-sample magnetometry data revealed PEG400 and PEG600 with obvious room-temperature ferromagnetism properties. In UV–Vis spectroscopy, the absorption edge exhibited a blue shift as the polymerization degree of PEG rose. In sum, BiFeO3 nanopowder possessed room-temperature ferromagnetism, thereby suitable photocatalyst for wastewater treatment and environmental purification with convenient recycling and substantial economic value.

In-situ TEM observation and molecular dynamics simulation were used to investigate the evolution of irradiation-induced dislocation loops and their interactions with the pre-existing dislocation lines in molybdenum irradiated by 30 keV He+ at 673 K. The nucleation, annihilation, merging, size change, and types of dislocation loops were investigated in detail, and the hardening effect from dislocation loops was analyzed. With the increase of helium fluence, the volume number density of dislocation loops increased rapidly and then decreased slowly to a saturation value, while the average size of dislocation loops increased continuously until it reached an upper limit. Both 1/2 and loops were formed, with a proportion of 60.2% to 39.8% at 3.95 × 1015 He+.cm−2 (0.07 dpa). The pre-existing dislocation lines would suppress the nucleation and growth of the dislocation loops, while the irradiation-induced dislocation loops had a strong pinning effect on the dislocation lines and impeded their motion. Molecular dynamics simulations were used to clarify the atomistic mechanisms of some major features of the line-loop interactions observed in the in-situ experiment, which showed in a good agreement. The different interaction processes depended on the Burgers vector and plane of the dislocation loop, the motion and reaction kinetics of dislocation segments, and the external loading.

A unique surface-modified rice-starch-based disordered carbon (SRC) was prepared with the intention of improving the electrochemical properties of anodes for Li-ion batteries. The starch’s surface was altered via an enzymatic hydrolysis process, and these changes were retained following a heat treatment process to create a porous surface. Following surface modification, SRC-based anodes exhibited a higher reversible capacity and coulombic efficiency in the first cycle at the same current density when compared with unmodified rice-starch-based disordered carbon (RC). SRC-based electrodes also displayed improved rate capability behavior and cycling performance. Across the measurements performed during this body of work, the electrodes’ performances were improved when (i) the contact area between the SRC particles and the electrolyte was maximized and (ii) the ordering of the particles on the surface was improved. These results indicate that this is a viable approach for the creation of anodes for Li-ion batteries from modified biomass sources.

For realizing two-dimensional (2D) spintronic devices, controllable manipulation of different spin channels is needed. In order to achieve this goal, the materials should have well-separated spin energies induced by spin–orbit coupling (SOC). However, a negligible SOC effect in 2D SnO limits its application in this prospect. Herein, we demonstrate that the stable Janus structure of SnPbO2 can exhibit large spin splitting (67 meV) at the valence band maximum (VBM) due to the breakdown of inverse symmetry. This spin splitting is larger than the thermal fluctuation at room temperature as well as some other 2D systems. In addition, the splitting can be further enhanced by strains (82 meV) or hole doping (147 meV). More importantly, there are no other electronic states except for the Rashba states at the VBM, which make it ideal for practical applications. Our study provides alternative ways to regulate the electronic structure of SnO and the feasibility for spin manipulation in this interesting 2D system.

In this study, Corydalis yanhusuo extract acts as a green inhibitor for J55 steel in 3.5% NaCl solution saturated with CO2. Rapid resolution liquid chromatography shows the concentrations of Palmatine to be 0.6358 g/L, Tetrahydropalmatine 0.7715 g/L, and Corydaline 0.3755 g/L. Potentiodynamic polarization results suggest that Corydalis yanhusuo extract is a mixed-type inhibitor. The inhibition efficiency of Corydalis yanhusuo extract increases with the increase of concentration and reaches 92.36% at 5%v/v but decrease with the increased temperature. The inhibition efficiency is 69% at 80°C. The protective film formed on the metal surface was confirmed by Fourier transforms infrared spectroscopy, UV–visible, scanning electrochemical microscope and scanning electron microscope methods. The quantum chemical calculations predicate that Palmatine acts as the major component for inhibition performance.

A novel tri-component hybrid, Pt/pyridine ionic liquid polyoxometalate/reduced graphene oxide denoted as Pt/(epy)3PMo12O40/rGO with well-dispersed, smaller size Pt nanoparticles on rGO is successfully synthesized. The morphology, structure, composition and electrochemical property are characterized by high resolution transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, energy dispersive spectrometer, Raman spectra, thermogravimetric analysis and cyclic voltammetry, respectively. Ionic liquid polyoxometalate (epy)3PMo12O40 availably prevents the aggregations of Pt nanoparticles on the rGO surface, furthermore, effectively improves anti CO poisoning performance and enhances the conductivity of the material. The mass activity of as-prepared Pt/(epy)3PMo12O40/rGO catalyst for methanol oxidation is about 10 times of 20% commercial platinum carbon, 7 times of Pt/rGO, 4 times of Pt/epyBr/rGO, and 2 times of Pt/H3PMo12O40/rGO. This further demonstrates that the ionic liquid polyoxometalate (epy)3PMo12O40 play a very important role in enhancing the eletrocatalytic activity of the tri-component hybrid composite catalyst.

The development of a low-cost and durable non-precious metal-based electrocatalyst for the hydrogen evolution reaction (HER) is important to realize highly efficient overall water splitting. Here, we report the design and fabrication of a binder-free electrocatalyst of three-dimensional macroporous ditungsten carbide (W2C) inverse opal (W2C IO) arrays by a facile thermal carburization process with WO3 IO as a template. The as-fabricated W2C IO exhibits superior electrocatalytic performance in 0.5 M H2SO4 solution in terms of a low overpotential of 146 mV to reach a current density of 10 mA cm−2, a low Tafel slope of 78 mV dec−1 and excellent long-term stability. The superior performance can be attributed to the favorable electronic structure and hydrogen adsorption Gibbs free energy of W2C evidenced by theory calculations and the enhancement of the charge/mass transfer process by the 3D macroporous arrayed electrode design.

The manipulation of valley splitting has potential applications in valleytronics, which lacks in pristine two-dimensional (2D) InSe. Here, we demonstrate that valley physics in InSe can be activated via the magnetic proximity effect exerted by ferromagnetic FeI2 substrate with spin-orbit coupling. The valley splitting energy can reach 48 meV, corresponding to a magnetic exchange field of ~800 T. The system also presents magnetic anisotropy behavior with its easy magnetization axis tunable from in-plane to out-of-plane by the stacking configurations and biaxial tensile strain. The d-orbital-resolved magnetic anisotropic energy contributions indicate that the tensile strain effect arises from the increase of hybridization between minority Fe dxy and dx2&minus, y2 states. Our results reveal that the magnetic proximity effect is an effective approach to stimulate the valley properties in InSe to extend its spintronic applications, which is expected to be feasible in other group-III monochalcogenides.

Constructing vacuum-ultraviolet beamlines at synchrotron radiation facilities with giga-electron volt storage ring results in serious heat load on the beamlines which can reduce their performance. To solve this problem, an APPLE-Knot undulator with eight magnet rows has been built at the Shanghai Synchrotron Radiation Facility and has achieved very good performance. However, its performance in vertical polarization mode is imperfect. Here, a new configuration of a magnet-merged APPLE-Knot undulator that has achieved a better performance is reported.

A facile strategy has been developed to realize the controllable synthesis of two dimensional (2D) single crystalline ZnCo2O4 nanosheet arrays (h-ZCO NSs) on the Ni foam surface. According to the SEM, TEM and BET analysis, it was found that the h-ZCO NSs have a hexagonal structure with a thickness of ca. 84 nm, and display a high specific surface area of 94.1 m2 g–1 with the pore size distribution of ca. 8 nm. As electrochemical capacitor electrode, h-ZCO NSs show large specific capacitance (1004.9 F g−1 at 3.3 A g–1), good rate capability and excellent cycling stability (93.5% capacitance retention after 2000 cycles at 10.0 A g–1), indicating better electrochemical performance. Additionally, serving as a gas sensor, h-ZCO NSs also exhibit remarkable sensitivity and selectivity towards methanol gas. All these impressive performances suggest that the h-ZCO NSs are a promising electrode material for electrochemical capacitors and gas sensors.

This work focuses on mechanism of heat generation in an agitating drum with dense gas-solid flow where particles move at high velocity (30 m/s). Numerical simulations and experiments are used to study the influence of granular flow characteristics, design parameters, process parameters and particle properties in heat generation and energy-conversion coefficient. Heat generates from sliding friction, rolling friction, viscous force of liquid-bridge or the modeled particle deformation. The variable goes to liquid volume due to high temperature (533 K) in wet particle flows. Concerning the velocity and particle motion several thermal transfer models are modified to match particle/particle and particle-wall/blade collisions, which are integrated to DEM-CFD numerical simulation. Experiments detected the temperature of external drum wall, the effect of temperature on liquid phase and the granular motion by visualization tests. The numerical results are verified by experimental data with good agreements. The effects of agitating speed and initial filling degree on temperature increase are not always in positive correlation, which are more significant in wet particles flow. Numerical simulations predicted the dynamic particles characteristic, the heat resources and the thermal conduction to reveal the heat generating mechanisms. Besides, the improved blades design to enhance heat generation is analyzed qualitatively and deduced.

The composites of N-doped ordered mesoporous carbon (N-CMK-3) anchored with tin disulfide (SnS2) nanosheets (NSs) have been synthesized via a maneuverable hot bath method at low temperature. The as-synthesized SnS2@N-CMK-3 composites exhibit a hierarchical structure with two dimensional (2D) SnS2 nanosheets uniformly grown on N-CMK-3, leading to a large specific area (126.7 m2 g−1) with mesoscale porosity. As anode material for lithium ion batteries (LIBs), SnS2@N-CMK-3 composite exhibits a high initial capacity of 1438.9 mA h g−1 (200 mA g−1). Moreover, the electrochemical performance remained at 618.9 mA h g−1 after 200 cycles, which are significantly higher than that of the pristine SnS2. The outstanding electrochemical properties might be due to the 2D nanosheet-morphology feature of SnS2 and the addition of N-CMK-3 that could availably inhibit the agglomeration of active substances and raise the conductivity of the composite electrode.

Structural failure of polyaniline (PANI) stemmed from repeated swelling-shrinkage during Faradic process represents an imminent issue hindering the real application of this material for advanced energy storage. Herein, we explore a clean and facile hydrogel-mediated layer-by-layer strategy to conformally coat a layer of oriented PANI nanofibers on multi-walled carbon nanotubes (MWCNTs) where a layer of UV-polymerized poly(acrylic acid) (PAA) hydrogel is first formed in between as electrodes for supercapacitors. Such an intriguing core-shell tri-component structure perfectly alleviates the drawbacks of PANI as well as combines the advantages of MWCNTs. Especially, the hydrogel used increases the adhesion between PANI and MWCNTs, buffers the structural variation of PANI during cycling, and provide extra driving force accelerating electrolyte penetration throughout active materials. Therefore, the well-intergrown hybrids (PANI/P-MWCNT) display high electrochemical performance as compared to PANI and PANI/MWCNT, i.e., an improved capacitance of 612.5 F g–1 at 0.5 A g–1, and excellent cycling behavior of 81.5% capacitance retention at 5 A g–1 over 1500 cycles. Also, the maximum energy density of the PANI/P-MWCNT based symmetric configuration reaches 8.2 Wh kg–1. Significantly, such a hydrogel-bridged design concept may find the important application for the synthesis of competitive candidates for energy storage.

Transition metal sulfide compounds with carbon materials are promising for high-performance supercapacitors. Carbon nanofibers (CNFs) wrapped with NiS nanoparticles were herein obtained through electrospinning and calcination. NiS nanoparticles in composite nanofibers are covered by a layer of graphitic carbon, which not only increase the conductivity but also provide active regions for nanoparticle growth to prevent aggregation. The CNFs-NiS electrode has high specific capacity of 177.1 mAh g −1 at 1 A g −1 (0.41 mAh cm −2 at a current density of 2.3 mA cm −2 ) and long-term cycling stability, with 88.7% capacitance retention after 5000 cycles. The excellent electrochemical activity may be attributed to the accessible specific surface, unique porous structure of CNFs and high specific capacitance of NiS. In addition, the asymmetric supercapacitor has an enhanced volumetric energy density of 13.32 mWh cm −3 at a volumetric power density of 180 mW cm −3 and high cycling stability, with 89.5% capacitance retention after 5000 cycles. It also successfully lights up a light-emitting diode. The CNFs-NiS composite has significant potential applications in supercapacitor.

Hollow and core–shell particles are currently attracting global attention because of their special properties. We herein proposed a facile self-sacrificial template strategy for the synthesis of cobalt tetraoxide (Co3O4) with hollow and core–shell nanostructures. Starting with metal formate framework (MFF) template [CH3NH3][Co(HCOO)3], a series of core–shell nanostructure MFF@Co(OH)2 microboxes and hollow Co(OH)2-H were successfully obtained through a reaction between the MFF template and sodium hydroxide (NaOH) combined with different washing processes. Finally, hollow and core–shell nanostructure Co3O4 products were obtained after calcination, which inherited the structures from corresponding precursors. In addition, the formation processes of hollow and core–shell nanostructures were studied. Moreover, the catalytic activity of the as-obtained Co3O4 for carbon monoxide (CO) oxidation was investigated. Such hollow and core–shell nanostructures gave different physiochemical properties. Hollow structure C...

Coal-based multiscale porous carbon materials (CPCs) have been successfully fabricated through a friendly method with NaCl, Na2CO3, and Na2SiO3 as structural templates, instead of alkali activation...

Lithium-sulfur batteries have several disadvantages, such as intrinsic insulation of sulfur and Li 2 S, large volume expansion, and inevitable shuttle effect, which lead to low utilization of active materials and rapid capacity decay. Herein, leaf-like interconnected network structure of MWCNT/Co 9 S 8 was synthesized by a simple hydrothermal method. The MWCNT/Co 9 S 8 /S delivers a high specific capacity and good cycling stability. The initial discharge capacity of MWCNT/Co 9 S 8 /S is 1124 mAh g −1 and retains at 503 mAh g −1 after 100 cycles at 0.1 C. The improved electrochemical performance of MWCNT/Co 9 S 8 /S could be attributed to the interconnected network MWCNT and polar Co 9 S 8 . As conductive skeletons, the interconnected network structure of MWCNT midribs provide fast conduction paths for electron and additional space for volume expansion of sulfur. Furthermore, sulfur particles well-distributed on the MWCNT/Co 9 S 8 scaffold facilitate Li + ions storage and release for energy delivery, which is beneficial to excellent activation of sulfur and high rate capacity. In addition, the polar Co 9 S 8 leaves provide strong binding sites to trap polar polysulfide intermediates, which can suppress the shuttle effect effectively.

Cobalt-based, nitrogen-doped porous carbon materials with in situ grown carbon nanotubes (CNTs) were synthesized by the facile carbonization of porous 3D Bio-MOF-11 [Co2(ad)2(CH3COO)2]·2DMF·0.5H2O (ad = adenine). Co-N/PC@CNT-Ts inherit the octahedral shape from the precursor, and have a porous structure with in situ grown CNTs catalyzed by Co particles. Co-N/PC@CNT-T materials have excellent activities as bifunctional electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in 0.1 M KOH electrolyte. Among the Co-N/PC@CNT-Ts, Co-N/PC@CNT-700 has the highest electrocatalytic activity. For ORR, Co-N/PC@CNT-700 has a higher onset potential of 0.92 V vs. reversible hydrogen electrode (RHE), high stability and methanol tolerance, which are even better than that of Pt/C. For OER, it has a low potential of 1.63 V at a current density of 10 mA cm-2. In addition, Co-N/PC@CNT-700 affords a low reversible overvoltage (bifunctional performance parameter) of 0.862 V between ORR and OER compared to the current advancing bifunctional catalysts. The superb bifunctional activity can be attributed to uniform CoNx active sites embedded in graphitized carbon, unique in situ grown CNT structure and ordered mesoporous structure. The synergistic effect enlarged the contact surface, exposed more active centers and provided many pathways, thereby boosting the electrocatalytic performance. In conclusion, this study provides a novel avenue for the application of stable transition metal-based, nitrogen-doped carbon materials as extremely efficient electrocatalysts for ORR and OER.

Hierarchical mesoporous LiNi1/3Co1/3Mn1/3O2 spheres have been synthesized by urea-assisted solvothermal method with adding Triton X-100. The structure and morphology of the as-prepared materials were analyzed by X-ray diffraction and electron microscope. The results show that the as-prepared samples can be indexed as hexagonal layered structure with hierarchical architecture, and the possible formation mechanism is speculated. When evaluated as cathode material, the hierarchical mesoporous LiNi1/3Co1/3Mn1/3O2 spheres show good electrochemical properties with high initial discharge capacity of 129.9 mAh g−1, and remain the discharge capacity of 95.5 mAh g−1 after 160 cycles at 10C. The excellent electrochemical performance of the as-prepared sample can be attributed to its stable hierarchical mesoporous framework in conjunction with large specific surface, low cation mixing and small particle size. They not only provide a large number of reaction sites for surface or interface reaction, but also shorten the diffusion length of Li+ ions. Meanwhile, the mesoporous spheres composed of nanoparticles can contribute to high rate ability and buffer volume changes during charge/discharge process.

The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) play crucial roles in efficient energy conversion and storage solutions. Here, Co@Co 3 O 4 nanoparticle embedded nitrogen-doped carbon architectures (denoted as Co@Co 3 O 4 /NCs) are prepared via a simple two-step and in situ approach by carbonization and subsequent oxidation of Co-MOF containing high contents of carbon and nitrogen. When evaluated as electrocatalyst towards both ORR and OER in a KOH electrolyte solution, the as-fabricated Co@Co 3 O 4 /NC-2 exhibits similar ORR catalytic activity to the commercial Pt/C catalyst, but superior stability and good methanol tolerance. Furthermore, the as-fabricated catalysts also show promising catalytic activity for OER. The effective catalytic activities originate from the synergistic effects between well wrapped Co@Co 3 O 4 nanoparticles and nitrogen doped carbon structures.

Two series of the ferrite-based materials have been synthesized for an oxygen evolution reaction (OER) activity screening. Series 1 includes different types of the ferrites: S-type (BaFe2O4), R-type (BaFe4Ti2O11), M-type (BaFe12O19) and tetravalent substituted M-type (BaFe11TiO19, BaFe10Ti2O19). Series 2 consists of a divalent substituted M-type ferrites (BaFe11·9Co0·1O18.95, BaFe11·9Ni0·1O18.95, BaFe11·9Zn0·1O18.96). The thermodynamic and electrokinetic approaches have been used to evaluate the best catalyst from both series of samples. According to the thermodynamics BaFe11·9Ni0·1O18.95 is the most preferable, while according to the kinetics BaFe10Ti2O19 has the best Tafel slope.

Appropriate material is the key to improve the energy and power density of sodium ion batteries. Herein, monoclinic Cu2Se is acquired by a facile one-pot solid method using Cu foil and Se power as the raw materials without use of expensive reagents and sophisticated instruments. Cu2Se exhibits preeminent cycling and rate properties. Concretely, Cu2Se represents reversible capacity of 264 and 241 mAh g−1 at 0.1 and 10 A g−1, as well as high capacity retention of ≈100% over 1000 cycles at 1 A g−1. When Cu2Se is applied as anode to assemble full battery with Na3V2(PO4)2F3@rGO, this battery exhibits a largest energy density of 97 Wh kg−1 (with a power density of 117 W kg−1) and a biggest power density of 1180 W kg−1 (with energy density of 59 Wh kg−1) based on the gross mass of cathode and anode active materials. A combination of ex-situ X-ray diffraction, transition electron microscopy tests and first-principle calculations demonstrate a reversible transformation between Cu2Se and Cu exists in the discharge-charge process. Stable solid-electrolyte interface film, highly infiltrative electrode and capacitive Na + storage behaviours are in favor of the excellent property. The preeminent electrochemical performance indicates that Cu2Se is a highly desirable anode material for high-performance sodium ion batteries.

A series of smulti-heteroatom doped Cu1.8Se/C composites are synthesized through a one-step direct selenization of Cu-based MOF containing hexa(4-carboxyl-phenoxy)-cyclotriphosphazene (HCTP-COOH) ligand. The MOF-derived Cu1.8Se/C composites with nanosheet structures are characterized to be Cu1.8Se nanoparticles embedded in carbon matrix doped with N, P and O atoms. The superior sodium-storage performance of Cu1.8Se/C-450 composite is proven to be resulted from the high specific surface area, the unique structure and the multi-heteroatom doping. The Na-ion half-cells from Cu1.8Se/C-450 electrodes exhibit a maximum capacity of 372.9 mA h g−1 at 50 mA g−1, an satisfactory rate capacity (133.3 mA h g−1 at 5 A g−1) and modest cycling stability. A sodium-ion hybrid capacitor (SHIC) device Cu1.8Se/C-450//AC assembled with Cu1.8Se/C-450 and AC shows desirable energy-storage properties. It delivers a maximum energy density of 65.8 W h kg−1 at 81.4 kW kg−1, and a capacity retention of 75.3% with 3000 testing cycles at 2 A g−1 with the operation voltage window of 0–4.0 V. The prospects of stated materials synthesis strategy and application of the as-prepared material Cu1.8Se/C-450 in SHIC device are presented.

The inhibitory effect of two heterocyclic porphyrin compounds, specifically 5,10,15,20-tetrakis(pentafluorophenyl)-21H,23H-porphyrin palladium(II) (PF-1) and 4,4′,4″,4‴-(porphyrin-5,10,15,20-tetrayl)tetrakis(benzoic acid) (PF-2), was studied in a sweet corrosion environment (3.5 wt % NaCl + CO2) on J55 steel by means of weight loss and electrochemical methods. Surface changes were studied using contact angle, scanning electrochemical microscopy (SECM), and atomic force microscopy (AFM) techniques. It was established that PF-2 showed the superlative inhibition efficiency of average of about 93% at 400 ppm concentration. The inductive behavior of the J55 steel surface in the presence of inhibitors was confirmed by SECM. The AFM further confirmed that the surface roughness was considerably decreased in the presence of porphyrins. The surface wettability of the steel was also investigated, and the results established the formation of a water-repellant layer on the surface when porphyrins are absorbed and layer became more hydrophobic with PF-2. Thermodynamics studies showed that the inhibition efficiencies of two compounds evaluated by all measurements follow the Langmuir adsorption isotherm.

By 60 Co-γ irradiation method, the Chitosan-oligosaccharide (COS) was grafted onto the inner surface of the polystyrene (PS) microtiter, which was soaked with COS solution before the irradiation. To evaluated the effect of COS concentration on the properties of the PS microtiter, FTIR, XPS, AFM, Contact angle tester and enzyme-linked analyser was used to measure the surface properties and BSA adsorption of PS-COS plates. The results shows that, with the increase of COS concentration, the contact angle clearly decreased at the dose of 12 kGy. The absorbance variances of the COS modified plate is less than 5% while the BSA adsorption is higher than the PS plates. The COS-modified microtiter has the potential applications in biochemical analysis.

A poor performance of the ternary cathode material, LiNi 1/3 Co 1/3 Mn 1/3 O 2 , at rate capability and low temperature, limits its further application, in electronic markets. Some of the previous research works report that surface modification of cathode materials can enhance their cycle stability. In the current work, (42.5-x) Li 2 O: 57.5B 2 O 3 : xLi 2 SO 4 modified LiNi 1/3 Co 1/3 Mn 1/3 O 2 cathode materials are prepared via the solution method followed by heat-treatment at 500 °C. The lithium fast ion conductors (42.5-x) Li 2 O: 57.5B 2 O 3 : xLi 2 SO 4 provide a stable surface protection for LiNi 1/3 Co 1/3 Mn 1/3 O 2 . The results indicate that (42.5-x) Li 2 O: 57.5B 2 O 3 : xLi 2 SO 4 modified LiNi 1/3 Co 1/3 Mn 1/3 O 2 exhibits enhanced electrochemical performance at high rates and low temperatures. (42.5-x) Li 2 O: 57.5B 2 O 3 : xLi 2 SO 4 (x = 10) modified LiNi 1/3 Co 1/3 Mn 1/3 O 2 samples increase the discharge capacity retention of LiNi 1/3 Co 1/3 Mn 1/3 O 2 from 33.4% to 85.3% at the rate of 1C and from 48.6% to 70.0% at −20 °C. The high resolution transmission electron microscopy and scanning electron microscopy confirm the existence of a thin Li 2 O-B 2 O 3 -Li 2 SO 4 coating layer (about 10 nm) on the original structure of LiNi 1/3 Co 1/3 Mn 1/3 O 2 . The cyclic voltammetry and electrochemical impedance spectroscopy test results demonstrate that the presence of LBO-S coating reduces the interfacial resistance towards lithium ion migration.

In this work, NiCo 2 O 4 nanowalls composed of ultrathin nanosheets are fabricated successfully on Ni foam by a facile one-pot solvothermal method followed by thermolysis of the precursors. The as-prepared NiCo 2 O 4 products are evaluated as electrode materials for supercapacitors and lithium ion batteries. The results show high discharge capacitance of 925 mF/cm 2 at a current density of 5 mA/cm 2 , with remarkable cycling stability (about 24.2% loss after 6000 cycles) and excellent rate performance (71.5% capacitance retention with current density range from 1 mA/cm 2 to 20 mA/cm 2 ). In addition, Ni foam supported NiCo 2 O 4 nanowalls possess excellent discharge capacity of 1100 mAh/g as lithium ion battery anode at a current density of 100 mA/g. The excellent electrochemical performance of NiCo 2 O 4 nanowalls could be ascribed to the unique spatial structure composed of interconnected ultrathin nanosheets, which facilitates ion penetration and electron transportation, demonstrating their potential applications as electrode materials for high performance supercapacitors and lithium ion batteries.

Pomelo peel extract (PPE) has been evaluated as a corrosion inhibitor for N80 steel in 3.5% NaCl saturated with CO2 solution using weight loss measurements, Fourier transform infrared spectroscopy, potentiodynamic polarization, electrochemical impedance spectroscopy, scanning electron microscopy (SEM), scanning electrochemical microscopy (SECM) and quantum chemical calculations. The inhibition efficiency was found to increase with increasing PPE concentration. Potentiodynamic polarization measurements indicated that the PPE was a mixed type inhibitor. The adsorption of PPE obeyed the Langmuir adsorption isotherm and mainly the physical adsorption. The SECM and SEM studies were used to investigate adsorbed film on the N80 steel surface. Quantum chemical calculation indicated that the major component of the PPE has more tendencies for adsorption.

Porous carbon nanotubes (PCNTs) containing sulfur were successfully fabricated through a simple approach, which is the simultaneous activation and carbonization of sulfonated polydivinylbenzene nanotubes with KOH. The PCNTs take on hierarchical porous structure composed of well interconnected mesopores and numerous micropores. Chemical analysis shows that the PCNTs contain sulfide and sulfone groups. When assessed as electrodes by a three-electrode system in 6 M KOH aqueous solution, the PCNTs displayed the excellent electrochemical performance. An optimal sample of PCNTs activated at 650 °C for 3 h not only exhibits a high specific capacitance of 331 F g−1 at 1 A g−1, but also shows considerable rate capability with the retention of 80.4% at 20 A g−1. Additionally, it has the good cycling performance with 84% capacitance retention, while a high capability of about 243 F g−1 still reaches over 5000 cycles at 5 A g−1. We presented a promising route to scale-up synthesize porous carbon nanotube electrode materials for high-performance supercapacitors.

A LiNi1/3Co1/3Mn1/3O2 (NCM) cathode material is coated with fluoroborate glass (xLi(2)O-yB(2)O(3)-zLiF) to improve the electro-chemical performance of lithium-ion batteries. An xLi(2)O-yB(2)O(3)zLiF layer was successfully coated onto the surface of NCM by using a solution-phase method. The resulting materials are characterized by using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The xLi(2)OyB(2)O(3)- zLiF-coated NCM exhibits a superior discharge capacity, rate capability, and cycling stability than those of the uncoated material. Notably, the initial discharge capacity of bare and 2Li(2) O-B2O3-LiF-coated NCM were 182.1 and 207.5 mAhg(-1), respectively, in the voltage range from 2.5 to 4.5 V. At a rate of 5C, the discharge capacity of Li2O-B2O3-LiF-coated NCM is 144.4 mAhg(-1), whereas that of bare NCM is 76.7 mAhg(-1). After 50 cycles at a rate of 0.2C, the capacity retentions of Li2O-B2O3LiF-, 2Li(2)O-B2O3-LiF-, Li2O-2B(2)O(3)-LiF-, and Li2O-B2O3-2LiF-coated NCM are 96.8, 97.2, 95.6, and 95.2%, respectively, whereas the capacity retention of bare NCM is 81.4%. Cyclic voltammetry and electrochemical impedance spectroscopy results indicate that the xLi(2)O-yB(2)O(3)-zLiF coating reduces electrode polarization and decreases charge-transfer resistance at the electrolyte-electrode interface, further improving the electrochemical activity of the NCM cathode material.

Hierarchically porous carbons offer great benefits for constructing advanced electrodes for energy-related applications. Herein, we reported facile synthesis of cross-linked carbon networks (HPCNs) made from N-doped nanosheets. By using MgO as self-sacrificial templates, the polyethylene glycol and melamine precursors were first uniformly coated on the template, and then annealed at the elevated temperature in inert atmosphere before removing the templates by mild acid etching. Interestingly, the capacitance performance of HPCNs could be easily modulated by adjusting the mass ratio of the precursors and templates, as well as the carbonization temperature. The optimized HPCNs showed specific capacitances of 192.6 F g −1 at 1.0 A g −1 and 156.2 F g −1 even at 20 A g −1 in 6.0 M KOH solution, and long-term cyclability with 85.5% capacitance retention at high current load of 10 A g −1 after 8000 successive cycles, which were attributed to structural merits of these continuous networks including high surface area of 370.8 m 2 g −1 , high pore volume of 1.65 cm 3 g −1 , as well as high nitrogen content of 9.920 wt.%. Owing to simplicity of the synthesis method and superior performance, such HPCNs may promise great potential in energy storage fields.

In this study, a highly active oxygen reduction reaction (ORR) electrocatalyst (MG-15) of Mn3O4 nanoparticles (NPs) supported by reduced graphene oxide (rGO) has been fabricated through one-step microwave-assisted synthetic route. Upon microwave-assisted synthesis, the formation of Mn3O4 NPs and the reduction of GO occurs simultaneously. Transmission electron microscope (TEM) profile reveals that Mn3O4 NPs are uniformly distributed evenly on the winkled rGO sheets. The MG-15 hybrid materials show enhanced electrocatalytic activity compared to rGO, Mn3O4 NPs and the mixture of rGO and Mn3O4 NPs, which indicates that the synergistic effect of Mn3O4 and rGO enhances the overall performance. Additional, the oxygen reduction peak of the MG-15 catalyst in a 0.1M KOH solution is tested at -0.15V, which is more positive than Pt/C (-0.154V). The onset potential of the MG-15 is close to Pt/C. Most importantly, the mechanism analysis shows that it favors the 4e- pathway for ORR. Furthermore, the MG-15 also exhibit excellent durability and methanol.

Mesoporous CeO2 core–shell microspheres were obtained by pyrolysis of a Ce–asparagine coordination polymer precursor. Then, upon a sheath-coating process via solvothermal treatment with Co(CH3COO)2·4H2O, Co3O4 species were uniformly dispersed on the CeO2 core–shell microsphere surface to generate the CeO2@Co3O4 composite. When used as catalysts for the oxidation of CO to CO2, the temperature required for full CO conversion was 280 °C and 170 °C for the core–shell microspheres CeO2 and CeO2@Co3O4-20 wt%, respectively. The porous structure with a core–shell architecture provided a larger surface area and abundant oxygen vacancies to adsorb and activate the CO molecules, resulting in an enhanced catalytic activity. Moreover, the CeO2@Co3O4 core–shell microspheres could maintain complete CO conversion after 30 h reaction. The enhanced CO conversion performance of the CeO2@Co3O4 core–shell microspheres was ascribed to the synergistic interaction between Co3O4 and CeO2.

For the first time, nitrogen and phosphorus codoped hierarchically porous carbon (NPHPC) has been explored as an efficient host for sulfur. The material is fabricated based on a scalable, one-step process involving the pyrolysis of melamine polyphosphate synthesized via a simple and versatile organic approach by using low cost industrial raw materials (melamine and polyphosphoric acid). The key features of NPHPC are the hierarchically porous structure and high surface area (1398 m 2 g −1 ) that not only benefit for maximum sulfur loading but also capable of suppressing the dissolution of polysulfides through physisorption. Meanwhile, the N and P codopants together with the thermally stable functionalities are favorable for binding polysulfides via chemisorption. Benefitting from the synergistic effect of structural confinement (physisorption) and chemical binding (chemisorption), the NPHPC/S composite with a high sulfur content of 73 wt% delivers high capacity (1580 mAh g −1 at 0.02 C) and long lifespan (200 cycles with 71% retention) for Li-S batteries. The present work highlights the importance of adopting heteroatom-doped hierarchically porous carbon for improving the performance of Li-S batteries, which may further stimulate more efforts in exploring advanced carbon-based hosts in the near future.

Porous MgO materials have unique and highly attractive properties. In this paper, porous MgO microstructures with hexagonal and double hexagonal pyramid architectures (MgO-hex and MgO-dhp) were prepared simply by annealing Mg-based metal–organic framework [NH4][Mg(HCOO)3]. The monodisperse porous MgO-hex and MgO-dhp products inherit the morphologies of the [NH4][Mg(HCOO)3] precursors and have large surface areas. The adsorption performance of porous MgO-hex and MgO-dhp were systematically tested towards Congo red (CR) as a model pollutant. The adsorption capacities are 1380 mg g−1 for MgO-hex and 1413 mg g−1 for MgO-dhp toward CR after 150 minutes at the initial concentration of 1000 mg L−1. The prepared MgO materials exhibit potential applications in wastewater treatment. The experimental data were fitted by two isotherm models, and the adsorption isotherm obeys the Langmuir model. Moreover, the kinetic studies indicate that the kinetic data followed a pseudo-second-order model.

Hierarchical porous carbon spheres (PCS) are prepared by a simple one-pot spray pyrolysis of coal oxide solution without any further activation process. The specific surface area and total pore volume of the resultant carbon spheres are increased significantly with the increase of spray pyrolysis temperature. When evaluated as electrode materials for supercapacitors in 6 M KOH electrolyte, the PCS exhibits a high specific capacitance 227 F g−1 at a current density of 1 A g−1 and outstanding cycling stability after 10 000 charge/discharge cycles at a current density of 2 A g−1. In symmetric supercapacitor, the specific capacitance of the sample PCS-8 is 180 F g−1 at a current density of 0.2 A g−1 and has excellent rate capability. The proposed strategy offers a facile and green method to produce porous carbon spheres from coal, and has potential application in energy storage.

Development of a Pd-based catalyst with highly active and durable properties for formic acid oxidation reaction at the anode remains an important matter of interest in the research community. Herein, we have designed novel coal-based carbon fibers (Coal-CFs) with dicyandiamide (DCD) as nitrogen (N) source, triphenylphosphine (TPP) as phosphorus (P) source dual-doped to support Pd catalysts (Pd/NP-Coal-CFs(DCD/TPP)), which exhibit superior catalytic performance toward formic acid oxidation reaction. Mass activity of formic acid oxidation of Pd/NP-Coal-CFs(DCD/TPP) catalyst is 536.6 mA·mg–1Pd, which is 2.5 times higher than that of Pd/Coal-CFs catalyst. The higher specific surface areas, exclusive electron transport path, and the high synergistic interaction of N and P are the favorable phenomena for catalytic performance. The addition of coal not only increases the abundant defects sites but also makes the utilization of coal with high added value. This N and P dual-doped catalyst inspires an idea for prom...

SnSe2 nanosheets, composed by small nanoparticles, have been synthesized via a solvothermal method with different times and temperatures. SnSe2 prepared at 180 °C for 25 h, exhibits small size of nanoparticles (5 nm), thin thickness of nanosheets (97 nm) and large surface area (6.32 m2 g−1), revealing good electrochemical performance. It achieves an initial charge capacity of 484 mAh g−1 at 0.1 A g−1, a high initial Coulombic efficiency of 82%, and a stable charge capacity of 361 mAh g−1 even after 200 cycles at 1 A g−1.

In this article, the biased sink behaviour of voids and bubbles to crystalline defects is examined through a properly trained machine learning model. The use of machine learning enables capturing more microstructural details than the conventional analytically-tractable sink strength formulae. With the present machine learning representation, for instance, the sink bias caused by opposite moving tendencies of vacancies against interstitial atoms in hydrostatic pressure fields, is naturally captured. Hence the roles played by several factors, such as the external loads, the number of gas atoms filling a bubble, and bubbles on crystalline interfaces, can be examined systematically. The findings here are shown good accordance with a spectrum of experimental/theoretical results related to sink bias concerning the loading conditions and grain boundaries on void/bubble growth. The present studies are thus expected to offer certain insights to controlling radiation-induced growth of bubbles by a mechanical means.

Transition metal chalcogenides have been investigated as underlying anodes for sodium ion batteries (SIBs). Nevertheless, the unsatisfactory property, which is determined by huge volume variation and low conductivity, restricts their practical applications. The design of micro-nano hierarchitectures is a resultful approach to strengthen structural stability and reaction kinetics during the discharge-charge process. Herein, urchin-like FeS2 hierarchitectures wrapped with reduced graphene oxide and N-doped multi-wall carbon nanotubes (FeS2@N-CNTs@rGO) are designed and synthesized by hydrothermal route. FeS2@N-CNTs@rGO shows high capacity with 578 mAh g−1 at 0.1 A g−1, splendid rate property with 419 mAh g−1 at 5 A g−1 and preeminent capacity retention (≈100%) over 750 cycles at 2 A g−1. The reversible phase transformation, capacitive Na+ storage behaviour and micro-nano hierarchitectures are responsible for the outstanding rate performance.

Recent researches demonstrate that functional materials (such as heteroatom doped carbon and metal oxides) as sulfur host can chemically adsorb lithium polysulfides, thereby alleviating the shuttle effect of Li-S batteries (LSBs). Herein, a hierarchical core-shell nanocomposites are rationally designed for enhancing the cycle performance of the sulfur cathode, which is constructed by ZIF-8 derived carbon core and hierarchical Mn3O4/N-doped carbon shell (ZPC@HMn3O4/NC). The ZPC core with highly porous structure can provide sufficient space for sulfur loading and physical adsorption of the polysulfides during cycling. Moreover, the hierarchical Mn3O4/NC shell play a dual role in physical restricting and offering strong chemical adsorption of polysulfides. As a result, the ZPC@HMn3O4/NC as sulfur host exhibits superior electrochemical performance. Specifically, ZPC@Mn3O4-NPC/S cathode with 71.5 wt% sulfur content shows an initial capacity of 1236 mAh g−1 at 0.1 C, an excellent rate capability of 430 mAh g−1 at 8 C and a long-term cycling performance of 301 mAh g−1 after 1000 cycles at 5 C.

In-situ irradiations with 30 keV He+ were performed on tungsten in an investigation of the influences of irradiation temperature and fluence, pre-existing dislocation and sample thickness on dislocation loop evolution including interaction, density and size. Dislocation loops with b = 1/2 and b = were found to form in tungsten during irradiation. The ratio of 〈100〉 loops was obviously affected by irradiation temperature, fluence, sample thickness and pre-existing dislocation lines. The interaction between high density helium clusters could stimulate the formation of 〈100〉 loops in irradiated W, which was verified by Molecular Dynamic (MD) simulations. In addition, the driving force for the 〈100〉 loop formation should also be attributed to the reaction of two 1/2 loop variants driven by long-time and elevated temperature irradiation. The pre-existing dislocation lines were found to have a profound effect on the size, density and Burgers vector of dislocation loops. Additionally, irradiation-induced defects were likely to be absorbed by the surface sinks of thin foil during ion irradiation, resulting in the formation of a denuded zone near the surface. The in-situ observation of irradiation defect evolution will lead to an improved fundamental understanding of irradiation damage process of tungsten serviced in fusion reactor.

A nanocomposite consists of N-doped carbon nanofibers and Co-containing MOFs (ZIF-67) derived ultrasmall Co3O4 nanoparticles (NCNF/Z-Co3O4 NPs) is prepared via introducing electrospun and coordination-assisted assembly strategies. In this design, Co2+ in the electrospun PAN-Co(Ac)2 nanofibers coordinate with 2-Methylimidazole (2-MeIM) to form ZIF-67 nanocrystals and further convert into ultrasmall Co3O4 NPs dispersed in the carbon fibers matrix. The carbon nanofibers serve as a highly conductive framework interconnect and confine the Co3O4 NPs, thereby improving the electrical conductivity and buffering the volume expansion of Co3O4. In addition, both N-doping originated from ZIF-67 and PAN, as well as the ultrasmall particle size of Co3O4 emerge the surface or near-surface redox reactions, enhancing pseudocapacitive contributions and rendering fast kinetics. Due to these advantages, NCNF/Z-Co3O4 NPs anode shows enhanced lithium storage properties (1189 mAh g−1at 0.1 A g−1, 407 mAh g−1 at 1 A g−1 after 850 cycles and 329 mAh g−1 at 8 A g−1).

Here, we present a systematical investigation of AlN/GaN double-barrier resonant tunneling diodes (RTDs) grown by plasma-assisted molecular beam epitaxy on metal-organic chemical vapor deposition GaN-on-sapphire templates. The processed devices featured an active region composed of 2.5 nm GaN quantum well sandwiched by two 1.5 nm AlN barriers and RTD mesa diameter ranging from 1 to 20 μm. Room temperature current–voltage characteristics exhibited a repeatable negative differential resistance (NDR) free of degradation and hysteresis after 1000 times subsequently up-to-down voltage sweeps across different sizes. High peak-to-valley current ratios of 1.93 and 1.58 were obtained at room temperature for 1 and 12 μm diameter devices, respectively, along with peak current densities of 48 and 36 kA/cm2 corresponding to peak voltages of 4.65 and 5.9 V. The peak current density decreased quickly initially and then was less susceptible to this averaging effect with increasing the device diameter. Temperature-dependent measurements revealed that the valley current density displayed a positive relationship to the temperature, and an abruptly increasement was observed for the devices with a diameter of 20 μm when the temperature rose over 230 K. We attributed this abnormal phenomenon to the increased contribution from acoustic and longitudinal optical (LO) phonon scattering, especially for the LO phonon scattering. The area dependence of electrical performance suggested that the leakage pathway through dislocations played a vital role for charge transport and there existed a threshold of dislocation density for NDR characteristics. These results promote further study for future implementation of III-nitride-based RTD oscillators into high-frequency and high-power terahertz radiation.

In this research the thermal, crystallization, and mechanical properties of branched poly (butylene succinate) (PBS) copolymers, which were synthesized through a two-stage esterification and condensation polymerization from 1,4-butanediol, 1,2-decanediol, and succinic acid and abbreviated as PBDS, were systematically investigated and compared with those of PBS homopolymer. Both PBS and PBDS copolymers showed relatively high and similar molecular weights, with the weight average molecular weights of 6.89 × 104 g/mol and above. PBDS copolymers showed the similar high thermal stability as PBS. With an increase in 1,2-decene succinate (DS) content, the glass transition temperature, melting point temperature, and equilibrium melting point temperature of PBDS copolymers gradually decreased. At the same cooling rate, the melt crystallization temperature of PBDS copolymers decreased, while at the same degree of supercooling, the crystallization half-time increased. The branching did not modify the crystallization mechanism and crystal structure of PBDS copolymers. Both the storage modulus and the glass transition temperature of PBDS copolymers gradually decreased with increasing the DS content. Compared with PBS, increasing the DS content obviously improved the elongation at break and accordingly decreased the Young's modulus and tensile strength of PBDS copolymers. In brief, the thermal, crystallization, and mechanical properties of PBS may be conveniently tuned by a copolymerization method via the introduction of branching.

Li4Ti4.94Tb0.06O12-δ has been synthesized via a facile co-precipitation method. The structure and morphology of the as-prepared sample have been characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and particle size distribution analysis. The results show that Tb3+ is successfully doped into the Li4Ti5O12 structure and that the average particle size is about 111 nm. Li4Ti4.94Tb0.06O12-δ exhibits a high initial discharge capacity of 166.5 mAh g−1 at 20 C, and the discharge capacity retention is nearly 93% after 500 cycles. In addition, the sample shows much improved rate capability at 20 C compared with pure Li4Ti5O12. Tb3+ doping not only enhances the electronic conductivity, but also improves the Li+ ion diffusivity in Li4Ti5O12, which indicates that Tb3+ doping is beneficial for promoting the electrochemical performance of Li4Ti5O12.