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Light-assisted antibacterial therapy is a promising alternative to antibiotic therapy due to the high antibacterial efficacy without bacterial resistance. Recent research has mainly focused on the use of near-infrared light irradiation to kill bacteria by taking advantage of the synergistic effects rendered by hyperthermia and radical oxygen species. However, photocatalytic antibacterial therapy excited by visible light is more convenient and practical, especially for wounds. Herein, a visible light responsive organic-inorganic hybrid of ZnTCPP/Ti

Graphene has attained a considerable amount of popularity as an attractive ultra-thin reinforcement for nickel (Ni) matrix composites in recent years. However, its excellent reinforcement efficiency is suffered from the agglomeration of graphene nanosheets in manufacturing process and the poor bonding strength of graphene with Ni matrix. To overcome these two problems, one of the efficient strategies is to in-situ grow graphene reinforcements on Ni particles for powder metallurgy. This work aims to synthesize uniform graphene@Ni composite particles by using polymethyl methacrylate (PMMA) as the solid sources for chemical vapor deposition (CVD) process. The results demonstrate that few-layer or multilayer graphene with different morphologies can be grown on the particles by controlling the PMMA content and annealed temperature, respectively. The optimum condition for the formation of high-quality few-layer graphene is 1.0 mg·ml−1 PMMA and 900 °C. A competition mechanism rises from the growth kinetic, and the spatial confinement effect has led to the formation of graphene with different microstructures and morphologies.

Using the first-principles methods, the effects of different alloying elements M (M = Fe, Ni, Mn, Si, Mo, Cu, Y) on Cr2O3 with Cl adsorption are studied. The results show that the layer distance of all doped models has been widened to different degrees with Cl adsorption. When Mo or Y is doped into the passive film, the difference of layer distance is reduced to a certain extent. The interaction between alloying elements and Cl is studied by calculating the adsorption height, bond population and electron density difference. The results show that Mo and Y can inhibit Cl erosion and improve the corrosion resistance of passive film. Furthermore, we investigate the CrMoFe and CrMoY co-doped system with Cl adsorption. The calculations point out that when Mo and Y are doped together in the passive film, the corrosion resistance of the system is more prominent than that of CrMo, CrY and CrMoFe co-doping systems.

Solid‐state NMR analysis on wurtzite alloyed CdSe1−xSx crystalline nanoparticles and nanobelts provides evidence that the 113Cd NMR chemical shift is not affected by the varying sizes of nanoparticles, but is sensitive to the S/Se anion molar ratios. A linear correlation is observed between 113Cd NMR chemical shifts and the sulfur component for the alloyed CdSe1−xSx (0, Finding the right composition: The 113Cd NMR chemical shifts of anion rich alloyed CdSe1−xSx materials are not affected by the nanoparticle size, but do change depending on the bound anion about the Cd(II) cation. Based on this correlation, a rapid and easy approach to determine the composition of the alloyed nanoscale materials has been developed by utilizing 113Cd NMR spectroscopy.

Engineering multicomponent active materials as an advanced electrode with the rational designed core-shell structure is an effective way to enhance the electrochemical performances for supercapacitors. Herein, three-dimensional self-supported hierarchical CoMoO4@CoS core-shell heterostructures supported on reduced graphene oxide/Ni foam have been rationally designed and prepared via a facile approach. The unique structure and the synergistic effects between two different materials, as well as excellent electronic conductivity of the reduced graphene oxide, contribute to the increased electrochemically active site and enhanced capacitance. The core-shell CoMoO4@CoS composite displays the superior specific capacitance of 3380.3 F g−1 (1 A g−1) in the three-electrode system and 81.1% retention of the initial capacitance even after 6000 cycles. Moreover, an asymmetric device was successfully prepared using CoMoO4@CoS and activated carbon as positive/negative electrodes. It is worth mentioning that the device delivered the high energy density of 59.2 W h kg−1 at the power density of 799.8 W kg−1 and the excellent cycle performance (about 91.5% capacitance retention over 6000 cycles). These results indicate that the core-shell CoMoO4@CoS composites offers the novelty strategy for preparation of electrodes for energy conversion and storage devices.

Owing to the unique merits benefited from the two-dimensional (2D) geometry, graphene has been often chosen as an attractive strength enhancer during the design of metal-graphene structural composites. In spite of the improved mechanical properties with the assistance of graphene, it is still challenging to fit the strength requirements for these metal-graphene composites in the practical applications. To address this issue, metal-doping and carbon-vacancy engineering, in this work, are first proposed to manipulate the dual-phase interfaces between metal and graphene in order to further strengthen the mechanical properties in metal-graphene composites based on the first-principle calculation. It can be concluded that a single-carbon-vacancy graphene or a Ti, Mn-doped metal matrix in metal-graphene composites delivers the best interfacial binding capability, resulting in an obvious strength increase of over 110% for Cu-graphene composites. Finally, the deformation mechanisms of metal-graphene composites are discussed via the evaluation on tensile deformation processes, electron densities, and stacking fault energies. This work offers us an alternative solution for the effective reinforcement on mechanical properties of metal-graphene composites by manipulating the dual-phase interfaces using doping or vacancy engineering.

The effects of B on microstructure, pitting and intergranular corrosion in solution-annealed S31254 super austenitic stainless steels were systemically investigated. After solid solution treatment at 1200 °C for different time, the precipitation and grain size of S31254 with and without B steels were analyzed. Addition of B to S31254 promotes the redissolution of detrimental sigma (σ) phases, and the optimum solid solution condition for B-containing S31254 is at 1200 °C for 2 h. The S31254 steels with B after solid solution treatment exhibited much better corrosion resistance than that without B, which is relative to the elimination of destructional σ precipitates and the decrease of chromium-depleted region near the grain boundary. Moreover, the passive films of samples with B have increased Cr2O3 and Mo-rich oxides, which may be responsible for the improvement of corrosion resistance.

Using density-functional calculations, we studied the interactions between interstitial impurities (H, O, N, S, and P) and Ni (111) surfaces doped, or not, with Cr, and studied the effect of Cr doping on the dissolution corrosion resistance of Ni(111) surfaces. The aim of this work was to study, at the atomic scale, the effects of Cr on the segregation behaviors of impurities and the synergetic effects between co-doped atoms on the resistance to dissolution corrosion of Ni (111) surfaces. The results indicate that impurities S, P, O, and H prefer to be trapped at near-surface sites, that Cr was uniformly distributed in the Ni crystal and can affect the segregation behavior of impurities S and P to move toward the surface, and it affects impurities N and O such that they shift from the surface to the subsurface. The formation of near-surface Cr nitrides (speculated to be Cr2N based on the results obtained for particular co-doped surfaces) was also noted. Introducing Cr enhances the structural stability of the Ni (111) surface and protects it from being corroded when impurities are present. The elementary processes studied afforded microscopic insights into the formation of a Cr-depleted zone, a phenomenon that leads to local corrosion of the Ni alloy surface. The results of our theoretical calculations explain some of the experimental results previously observed at the atomic scale.

Zintl phase compounds Ca9Zn4+xSb9 have promising thermoelectric properties due to their complex crystal structure and tunable interstitial Zn. In this work, we prepared nominal Ca9Zn4+xSb9 (x = 0.5...

The precipitation of the σ phase at the grain boundary (GB) has an important effect on the properties of super austenitic stainless steel. This study used density functional theory (DFT) calculations to assess the segregation of Mo and B atoms at the GB and their effects on GB strength. The results demonstrated that Mo and B atoms tend to converge to grain boundary positions and B atoms are easier to segregate than Mo atoms. In addition, B can restrain the segregation of Mo to grain boundary positions, making it difficult for the positions to form an σ phase. An analysis of the inhibitory effect of different contents of B on Mo indicated that higher B content is better for restraining Mo segregation to grain boundary sites. These results are beneficial for improving the shortcomings of super austenitic stainless steel. B can also increase the GB strength while inhibiting the segregation of Mo to grain boundary sites and a charge density analysis demonstrated the results.

Purpose The purpose of this study is to investigate the effect of iron content on the friction and wear performances of Cu–Fe-based friction materials under dry sliding friction and wear test condition. Design/methodology/approach Cu–Fe-based friction materials with different iron content were prepared by powder metallurgy route. The tribological properties of Cu–Fe-based friction materials against GCr15 steel balls were studied at different applied loads and sliding speeds. Meanwhile, microstructure and phases of Cu–Fe-based friction materials were investigated. Findings Cu–Fe-based friction materials with different iron content are suitable for specific applied load and sliding speed, respectively. Low iron content Cu–Fe-based friction material is suitable for a high load 60 N and low sliding speed 70 mm/min and high iron content Cu–Fe-based friction material will be more suitable for a high load 60 N and high sliding speed 150 mm/min. The abrasive wear is the main wear mechanism for two kinds of Cu–Fe-based friction materials. Originality/value The friction and wear properties of Cu–Fe-based friction materials with different iron content were determined at different applied loads and sliding speeds, providing a direction and theoretical basis for the future development of Cu–Fe-based friction materials.

High silica SSZ-13 zeolite was synthesized by an efficient and green steam-assisted crystallization (SAC) method under a low alkalinity and low organic templates amount system. The as-prepared samples were characterized by XRD, SEM, N2 adsorption–desorption, TG–DTG and NH3-TPD. The results showed that the SAC method can not only remarkably improve zeolite yield but also enhance the crystallization rate of SSZ-13 zeolite compare to conventional hydrothermal route. Meanwhile, it was also found that the various content of the organic structure directing agent (N,N,N-trimethyladamantammonium hydroxide, TMAdaOH) in the dry gel can adjust flexibly the crystal size, morphology and acidity of samples. The zeolite samples with smaller particles and more strong acidity amount were more likely obtained under the higher TMAdaOH/SiO2 ratio (0.2) condition. In addition, the catalytic evaluation in methanol-to-olefins (MTO) reaction showed that the high silica SSZ-13 catalysts synthesized by SAC method exhibited longer lifetime and comparative selectivity to ethylene and propene than those of the SSZ-13s obtained by conventional hydrothermal route. Thus, the SAC route is believed to be a competitive strategy to synthesize high silica SSZ-13 zeolites with improved MTO catalytic performance.

The transition metal oxides with multiple oxidation states and large electrical conductivity have been extensively studied in energy storage capacitors. Herein, the core-shell cobalt sulfide/manganese molybdate composites grown on reduced graphene oxide/Ni foam (CoS/MMO/rGO/NF) have been successfully prepared via hydrothermal and followed by electrodeposition methods. It is found that the deposition mass of CoS has a significant effect on the morphologies and electrochemical properties of CoS/MMO/rGO/NF electrodes. When the mass of CoS is 0.4 mg cm−2 (CoS-0.4/MMO/rGO/NF), the composite yields a remarkable specific capacitance of 3074.5 F g−1 (1 A g−1) and a good cycling performance of 87% through 5000 cycles. Moreover, an asymmetric device based on the CoS-0.4/MMO/rGO/NF composite shows a maximum energy density (50.3 W h kg−1 at 415.8 W kg−1) and a good long-term stability (retention 96% even after 8000 cycles). These characteristics of CoS-0.4/MMO/rGO/NF are mainly attributed to the high conductivity of reduced graphene oxide and the synergistic effects of MnMoO4 and CoS, as well as its unique morphology. These superior properties of CoS-0.4/MMO/rGO/NF demonstrate its potential application as electrode material in energy storage capacitors.

Graphene characterized with ultrahigh intrinsic strength and excellent electronic properties is an ideal material to reinforce metals without despairing their thermal and electrical properties. Here, the electronic and mechanical properties of graphene intercalated copper (graphene/Cu) composites are investigated using density functional theory calculations. Graphene/Cu systems present an excellent electrical conductivity and increasing Debye temperature from 335 K for pure Cu to over 535 K in regardless of stacking models. In addition to greatly enhanced Young's modulus (149%), shear modulus (156%) and bulk modulus (108%) compared to copper, the ultimate strength of graphene/Cu composites are enhanced by 174% and 162%, in x and y directions, respectively. The strengthening and toughening effects of graphene in the composites is originated from strain strengthening and load transfer, which is consistent with the experimental results. Based on this calculation, the strengthening mechanism can be understood, which explains many experimental observations and also provides us a guide to improve graphene/metal composites quality.

Because of the influence of hydrogen and the stress corrosion cracking, the damage of metal is quite frequent. It leads to dangerous failures, the loss of property as well as large compensational payments for insurance companies. However, the issue of the precise role of hydrogen in the process is unclear and the mechanism is not available. Based on the binding energy analysis, it was found that H prefers octahedral-like positions for γ-Fe, and could enhance the stability of structure with dissolving into γ-Fe. The higher the concentration of H, the much more remarkable the observation is. Therefore, H is easily soluble in γ-Fe. Under the applied tensile stress, γ-Fe and H doped γ-Fe undergo the stages of elastic and plastic deformations. Meanwhile, H induces γ-Fe phase transition.This process starts from the atomic layer adjacent to H, then gradually extends far. As a consequence, the intergranular embrittlement and cracking happened.

In this work, we focus on the magnetic properties and martensitic transformation behaviors in Ni40Mn44-xCoxAl16 (x = 5, 7) Heusler alloys. By partial substitution of Co for Mn, the martensitic transformation (MT) can be tuned in a wide temperature range and shifts to the higher temperature with the increase of Co content in these alloys. The reverse MT can be induced by magnetic field from the weak-magnetic martensite phase to ferromagnetic austenite phase in these alloys. The large magnetoresistance effect of −46.39% and −41.75% are acquired under 90 kOe for Ni40Co5Mn39Al16 and Ni40Co7Mn39Al16 alloys, respectively. The Ni40Mn44-xCoxAl16 alloys with large low-field magnetoresistance and low cost show promising applications for multifunctional materials.

SSZ-13 zeolite with a SiO2/Al2O3 ratio in the range of 26–183 was synthesized by adding zeolite L in the synthesis gel absent from additional aluminum source, and the effects of SiO2/Al2O3 and N,N,N-trimethyladamantammonium hydroxide (TMAdaOH)/SiO2 ratios on the crystallization were investigated. The crystallization mechanism was studied with X-ray diffraction, Scanning electron microscopy, Fourier transform infrared spectroscopy and 29Si and 27Al MAS NMR spectroscopy techniques. It is shown that the SiO2/Al2O3 and TMAdaOH/SiO2 ratios have a significant effect on the acidity, and thus, the methanol-to-olefins (MTO) performance of SSZ-13. The co-presence of TMAdaOH, NaOH and extra silica source (SiO2) is necessary for formation of SSZ-13. The crystallization of SSZ-13 occurs by decomposing structure of zeolite L into double six- and four-membered rings that subsequently restructure into CHA topology under the direction of TMAdaOH, and further induce the nucleation and crystal growth. It is noteworthy that the Al species in zeolite L directly transform into those of SSZ-13 without forming monomeric species. The prepared SSZ-13 shows higher catalytic stability and selectivity to ethylene and proplyene than the conventionally synthesized sample from amorphous aluminosilicate gel in MTO reaction.

The corrosion behavior of Ti62Zr12V13Cu4Be9 metallic glass matrix composites (MGMCs) in chloride-containing (NaCl and HCl) and chloride-free (NaOH and H2SO4) solutions was studied. As a result, Ti62Zr12V13Cu4Be9 MGMCs exhibits better corrosion resistance in chloride-free solutions due to the formation of oxide layer. In comparison, the oxide layer formed in NaOH solution is superior to that formed in H2SO4 solution according to the analysis results of XPS and EIS. The irregularity of elemental and phase distribution in this Ti-based MGMCs material is considered the driving force of the corrosion process. With the inclusion of other factors such as the different pH values and the cathodic reaction, rather reasonable interpretation about the difference of corrosion behaviors of Ti-based MGMCs samples in various media is proposed.

Effects of compression deformation on the sigma-phase precipitation behavior of B-containing S31254 stainless steel after solution treatment were studied using the Gleeble compression test. The cold and hot processing characteristics of B-containing S31254 stainless steel were evaluated, and the results show that the speed of compression deformation increased the precipitation rate of the sigma phase, and the location of precipitation extended from the austenite grain boundary to the original hot rolling deformation area. During cold deformation at room temperature, the precipitation rate increased when the deformation reached at 40%. Deformation at 950 °C affected precipitation more obviously. At 1074 °C, when the deformation reached 20%, the precipitated phases started increasing, and above this deformation range, precipitation began decreasing. Also, at 1074 °C, the deformation accelerated the precipitation of sigma phase; but with deformation, there was a change in critical temperature for the sigma-phase excursion. The precipitation position of the sigma phase is strongly related to the area of the original hot rolling deformation. With an increase in the deformation amount, precipitates in this region appeared as coarse-grained, skeletal, and network-like features.

2707 hyper-duplex stainless steels (HDSSs) contain high contents of alloying elements (Cr, Ni, Mo and N), which may shorten the incubation period and promote both nucleation and growth of sigma (σ) phase. 2707 HDSS was first aged at different temperatures and periods of time for drawing the time–temperature–transformation profiles. The results identified the main precipitates as σ phase, with nose temperature of about 950 °C. Also, 2707 specimen was aged at 950 °C for a short time, and the morphology, distribution and amount of σ phase were examined through the scanning electron microscope and X-ray diffraction. σ phase was initially formed at the boundaries of ferrite and austenite and then transformed through the eutectoid reaction (α → σ + γ2). Finally, the precipitation and growth of σ phase in 2707 steels aged at nose temperature for a short period reduced the corrosion resistance and deteriorated the mechanical properties, and the corresponding reason was further analyzed.

Photoelectric performance of (C, S) co-doped SnO2 was explored by an integrated strategy combining first principle calculation with experimental measurement. The exploration began with theoretical calculation upon geometry characteristic and electronic structure of pure and (C, S) co-doped SnO2, then follow by experimental measurement. Namely, pure and different ratios of (C, S) co-doped SnO2 were prepared and characterized by X-ray powder diffraction (XRD), scanning electron microscope (SEM), and X-ray photoelectron spectroscopy (XPS). And photoelectric performance of the prepared pure and (C, S) co-doped SnO2 electrodes was studied. Theoretical calculation result indicate that carbon and sulfur atom interact intensely to each other by lattice distortion. Fully filled energy levels are introduced to the top of the valence band, resulting effective reduction of band gap value and suppression of charged defects. Consequently, the photoelectric performance of SnO2 is improved. Double-hole-assisted coupling mechanism of dopants in SnO2 is interpreted to reveal the interaction of C and S. Besides, experimental results indicate that all samples are rutile phase with the dopants carbon and sulfur entered into SnO2 crystal by substituting oxygen. 5% co-doped sample shows the most homogeneous spherical shape and dispersed character, which is provided with the maximum photocurrent value (6.8 μA/cm2) and minimum electrochemical impedance. Theoretical calculation and experiment jointly indicate that (C, S) co-doped SnO2 possess superior photoelectric performance. The doping method of double-hole-assisted coupling may contribute to the design of highly active tin oxide-based photoelectric materials, and also pave the way for modification of other congener materials.

In the present work, three kinds of precipitates with different morphologies, structures, sizes, and volume fractions were obtained via energetically-tuning the microstructures of the nano-precipitated CoCrFeNiTi0.2 high-entropy alloy (HEA). Subjected to the heavy cold rolling immediately after homogeneous precipitation, L12 structured spherical nano-particles with an average size of 16.5 nm rapidly grow into 200 nm-sized spherical ones due to Ostwald ripening. On the other hand, superfluous mechanical energy storage energetically facilitates the phase transformation from spherical L12 to rod-shaped D024 structures for initially formed nano-precipitates. Besides, some other newly formed nano-precipitates with an average size of 6.5 nm are available, originating from heavily plastically deformed-induced nucleated sites. Multi-scale precipitates interact with dislocations in different ways. The strengthening provided by dislocations cutting through smaller nano-particles and bypassing grown ones account for 57.7% and 42.3% of precipitation strengthening, respectively, while rod-shaped precipitates can act as equivalent interfaces to hinder dislocation movement. Their synergistic effect has achieved remarkable strengthening and toughening. Specially, dislocation slips dominate at 298 K, while stacking faults (SFs) assist plastic deformation at 77 K. Compared with 298 K, the yield strength (YS) and ultimate tensile strength (UTS) of the current HEAs at 77 K are increased by 38.9% and 38.2% to 1 GPa and 1.5 GPa, respectively, and the tensile strain is slightly increased to 35% instead of loss, realizing excellent strength and plasticity combination. Theoretically established strengthening models agree well room-temperature and cryogenic yield strengths experimentally. Moreover, the tensile elongation is effectively predicted by the Whitehouse-Clyne model. This strengthening strategy of energetically-tuning polymorphous precipitates provides the basic guidance to develop high-performance nano-precipitated alloys. The current strengthening and plasticity models can be employed to well predict the mechanical properties of such kinds of alloys at cryogenic temperatures.

Hematite (&alpha, Fe2O3) is a promising electrode material for cost-effective lithium-ion batteries (LIBs), and the coupling with graphene to form Gr/&alpha, Fe2O3 heterostructures can make full use of the merits of each individual component, thus promoting the lithium storage properties. However, the influences of the termination of &alpha, Fe2O3 on the interfacial structure and electrochemical performance have rarely studied. In this work, three typical Gr/&alpha, Fe2O3 interfacial systems, namely, single Fe-terminated (Fe-O3-Fe-R), double Fe-terminated (Fe-Fe-O3-R), and O-terminated (O3-Fe-Fe-R) structures, were fully investigated through first-principle calculation. The results demonstrated that the Gr/Fe-O3-Fe-R system possessed good structural stability, high adsorption ability, low volume expansion, as well as a minor diffusion barrier along the interface. Meanwhile, investigations on active heteroatoms (e.g., B, N, O, S, and P) used to modify Gr were further conducted to critically analyze interfacial structure and Li storage behavior. It was demonstrated that structural stability and interfacial capability were promoted. Furthermore, N-doped Gr/Fe-O3-Fe-R changed the diffusion pathway and made it easy to achieve free diffusion for the Li atom and to shorten the diffusion pathway.

Uncontrollable electrochemical deposition of Li

Developing effective and low-cost catalysts toward oxygen evolution reaction (OER) is pivotal for hydrogen generation by water electrolysis. The preparation of transition metal based catalysts using the unique structure of metal-organic frameworks is considered a feasible approach. Herein, we have designed and synthesized a heterostructure electrocatalyst composed of FeS2 and MOF-derived CoNiSe2. The catalyst exhibits an extraordinary OER activity with a low overpotential of 230 mV to deliver the current density of 10 mA cm-2, a slight Tafel slope of 54 mV dec-1 in 1 M KOH, and robust durability up to 45 h. The result of density functional theory (DFT) calculations reveals that electronic coupling at the heterogeneous interface helps reduce reaction energy barriers and increase electrical conductivity. This work would provide some inspiration for explorations of advanced electrocatalysts with MOF-derived heterostructure.

The development of efficient bifunctional electrocatalyst for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline environment is crucial and challenging for large-scale hydrogen energy application. Herein, a heterostructure electrocatalyst on Ni foam (NF) with CoS nanosheet coupled with NiFe2O4 was synthesized via electrodeposition method with the assistant of thiourea followed by annealing treatment. Because of the unique three-dimension structure, this self-supported catalyst possesses high intrinsic conductivity, abundant active sites and excellent durability, acting as an exceptionally durable and efficient catalyst for HER and OER. The obtained CoS/NiFe2O4-15/NF exhibits HER and OER catalytic performance with overpotentials of 116 mV and 227 mV at a current density of 10 mA cm−2 in 1 M KOH, respectively. For CoS/NiFe2O4-15/NF||CoS/NiFe2O4-15/NF two-electrode system, the electrolyser requires 1.60 V to deliver 10 mA cm−2, and negligible loss of activity is observed after working for 12 h (10 mA cm−2). Moreover, the interface between oxide and sulfide is identified to play a major part in the catalysis of OER and HER. These excellent properties of CoS/NiFe2O4-15/NF electrode advance the electronic water splitting reaction for hydrogen production.

Sanicro 25 austenitic heat-resistant steel is expected to be used in superheaters and reheaters for ultra-supercritical power plants above 600 &deg, C due to its excellent structural stability and high temperature mechanical properties. In this paper, the effects of Co and W on the structural stability, thermodynamic stability and mechanical properties of Sanicro 25 steel are analyzed by calculating the formation energy, binding energy, Gibbs free energy, elastic constant, Peierls stress and generalized stacking fault energy (GSFE) with first-principles calculation method. By calculating the formation energy, binding energy and Gibbs free energy, it concludes that alloying elements Co and W in Sanicro 25 steel can improve the structural stability and thermodynamic stability. It indicates that W and a small amount of Co can improve the plasticity and ductility of Sanicro 25 steel by calculating the bulk modulus (B), shear modulus (G), Young&rsquo, s modulus (E), the B/G ratio, Poisson&rsquo, s ratio and Peierls stress. It is found that when Co and W are far from the stacking fault region, it will promote the formation of partial dislocations and twins in the system, thereby improving its plastic deformation ability and mechanical properties.

In the present work, a systematic analysis of the microscopic plastic deformation mechanism and mechanical properties of interstitial impurities (H, O, N, S, and P) and Ni doped, or not doped, with Cr, was conducted based on generalized stacking fault energy curves generated via first-principles calculations. Focus has been put on the effects of Cr on plastic deformation for Ni doped interstitial impurities, upon the GPFE curve, with the aim to investigate the effects of Cr on the deformation mode and mechanical properties for doped Ni systems. It is found that a solid solution of Cr caused the tendency of partial dislocation in Ni. The evaluation of the Rice criterion reveals that Cr tends to decrease the ductility in Ni, and it cannot reverse interstitial H promoting the probability of cleavage fracture in Ni, while increases the ductility of O, P and S doped Ni, particular in O doped Ni, due to increasing the value of ductility D remarkably, so possibly changes the tendency of cleavage fracture. Besides, the solid solution of Cr is beneficial in promoting the dissociation of dislocation into fragments more easily in Ni, and enhances dislocation nucleation, while O, N, and S impurities have a slower rate of partial dislocation emission in Ni when interacting with Cr. Furthermore, Cr promotes the probability of twinning in Ni, and probably switches the deformation mechanism of H doped Ni from dislocation mediated slipping to twinning. Our study provides important insights toward the understanding and control of dislocation dynamics in doped Ni.

Herein, zinc cobalt layered double hydroxide (ZnCo-LDH) hybrid composites with different Zn/Co molar ratios are in-suit grown onto Ni foam by a simple and cost-effective hydrothermal approach. It is found that the Zn/Co molar ratios have an important influence on the morphology and electrochemical performance of the ZnCo-LDH composites. An interconnected nanowires structure and the highest specific capacitance were achieved when the Zn/Co molar ratio is 1: 2 (Zn1Co2-LDH).Moreover, interconnected Zn1Co2-LDH is further combined with reduced graphene oxide stuck onto Ni foam (Zn1Co2-LDH@rGO/NF) to improve its electrochemical properties. Benefiting from its unique structural feature and excellent electrical conductance ability, the as-prepared material exhibits an enhanced specific capacitance of 2142.0 F g−1 as supercapacitor electrode. Remarkably, the assembled asymmetric supercapacitor device based on Zn1Co2-LDH@rGO/NF and active carbon delivers a high specific capacitance (149.6 F g−1), high energy density (53.2 Wh kg−1), and excellent long cycling stability (90.9% capacitance retention after 6000 cycles at 3 A g−1), which holds huge potential for practical application in energy conversion and storage fields.

Ternary metal sulfides such as manganese-cobalt-sulfide (MCS) with the unique physical, chemical properties and high specific capacity can be used as energy storage material for supercapacitor. Herein, we prepared a MCS nanosheet array stick onto reduced graphene oxide (rGO)/Ni foam (MCS/rGO/NF) by a carefully controlled sulfurization time process. As the reaction time increased, the thickness of MCS/rGO/NF nanosheet arrays charged from thin to thick. After 3 h of sulfurization reaction (MCS/rGO/NF-3h), the nanosheets became rough due to the formation of some small sheets, and the composite showed the best electrochemical performance. The MCS/rGO/NF-3h composite exhibited a large specific capacity of 1356 C g−1 at a current density of 1 A g−1, and a long-term cyclic stability of 92.9% at a current density of 10 A g−1 through 3000 cycles. Moreover, a hybrid supercapacitor (HSC) device was assembled using MCS/rGO/NF-3h and rGO as the positive and negative electrodes, respectively. The MCS/rGO/NF-3h//rGO HSC exhibited a high energy density of 45.4 W h kg−1 at a power density of 850.2 W kg−1. The prominent electrochemical performance suggests that MCS/rGO/NF composites are promising electrode materials for energy storage applications.

The electronic structure of Sb-N co-doped SnO2 was explored by first principles calculation. The results show that Sb (donor) and N (acceptor) introduce new energy levels in the band gap, which reduce the band gap of SnO2 obviously. Besides, the carrier separation rate of the system is improved owing to the charge compensation effect of Sb and N. Consequently, the photoelectric performance of SnO2 is improved. Based on the results of theoretical calculation, the intrinsic and different ratios of Sb-N co-doped SnO2 were prepared by hydrothermal method. And the samples were characterized by X-ray powder diffraction (XRD), scanning electron microscope (SEM), and x-ray photoelectron spectroscopy (XPS). The photoelectric performance of the prepared intrinsic and Sb-N co-doped SnO2 electrodes was studied. The results prove that all samples are rutile phase with the dopants Sb and N entered into SnO2 lattice by substituting Sn and O. Besides, the 5% co-doped sample has uniform spherical shape and dispersed character. The photoelectric performance tests indicate that photoelectric performance of SnO2 is enhanced by Sb-N co-doping. The maximum photocurrent value (9 μA/cm2) and minimum electrochemical impedance is achieved at the doping ratio of 5%. Theoretical calculation and experiment results indicate that Sb-N co-doped SnO2 possesses superior photoelectric performance.