An intrinsically self-healing and anti-freezing molecular chains induced polyacrylamide-based hydrogel electrolytes for zinc manganese dioxide batteries

The anti-freezing strategy of hydrogels and their self-healing structure are often contradictory,it is vital to break through the molecular structure to design and construct hydrogels with intrinsic anti-freezing/self-healing for meeting the rapid development of flexible and wearable devices in diverse service conditions.Herein,we design a new hydrogel electrolyte(AF/SH-Hydrogel)with intrinsic anti-freezing/self-healing capabilities by introducing ethylene glycol molecules,dynamic chemical bonding(disulfide bond),and supramolecular interaction(multi-hydrogen bond)into the polyacrylamide molecular chain.Thanks to the exceptional freeze resistance(84%capacity retention at-20℃)and intrinsic self-healing capabilities(95%capacity retention after 5 cutting/self-healing cycles),the obtained AF/SH-Hydrogel makes the zinc||manganese dioxide cell an economically feasible battery for the state-of-the-art applications.The Zn||AF/SH-Hydrogel||MnO_(2)device offers a near-theoretical specific capacity of 285 m A h g^(-1)at 0.1 A g^(-1)(Coulombic efficiency≈100%),as well as good self-healing capability and mechanical flexibility in an ice bath.This work provides insight that can be utilized to develop multifunctional hydrogel electrolytes for application in next generation of self-healable and freeze-resistance smart aqueous energy storage devices.

Hyphae-mediated bioassembly of carbon fibers derivatives for advanced battery energy storage

Ingenious design and fabrication of advanced carbon-based sulfur cathodes are extremely important to the development of high-energy lithium-sulfur batteries,which hold promise as the next-generation power source.Herein,for the first time,we report a novel versatile hyphae-mediated biological assembly technology to achieve scale production of hyphae carbon fibers(HCFs)derivatives,in which different components including carbon,metal compounds,and semiconductors can be homogeneously assembled with HCFs to form composite networks.The mechanism of biological adsorption assembly is also proposed.As a representative,reduced graphene oxides(rGOs)decorated with hollow carbon spheres(HCSs)successfully co-assemble with HCFs to form HCSs@rGOs/HCFs hosts for sulfur cathodes.In this unique architecture,not only large accommodation space for sulfur but also restrained volume expansion and fast charge transport paths are realized.Meanwhile,multiscale physical barriers plus chemisorption sites are simultaneously established to anchor soluble lithium polysulfides.Accordingly,the designed HCSs@rGOs/HCFs-S cathodes deliver a high capacity(1189 mA h g^(-1)at 0.1 C)and good high-rate capability(686 mA h g^(-1)at 5 C).Our work provides a new approach for the preparation of high-performance carbon-based electrodes for energy storage devices.

Flexible perovskite light-emitting diodes for display applications and beyond

The flexible perovskite light-emitting diodes(FPeLEDs),which can be expediently integrated to portable and wearable devices,have shown great potential in various applications.The FPeLEDs inherit the unique optical properties of metal halide perovskites,such as tunable bandgap,narrow emission linewidth,high photoluminescence quantum yield,and particularly,the soft nature of lattice.At present,substantial efforts have been made for FPeLEDs with encouraging external quantum efficiency(EQE)of 24.5%.Herein,we summarize the recent progress in FPeLEDs,focusing on the strategy developed for perovskite emission layers and flexible electrodes to facilitate the optoelectrical and mechanical performance.In addition,we present relevant applications of FPeLEDs in displays and beyond.Finally,perspective toward the future development and applications of flexible PeLEDs are also discussed.

Bifunctional electrolyte regulation towards low-temperature and high-stability Zn-ion hybrid capacitor

Aqueous Zinc-based energy storage devices are considered as one of the potential candidates in future power technologies.Nevertheless,poor low temperature performance and uncontrollable Zn dendrite growth lead to the limited energy storage capability.Herein,an anti-hydrolysis,cold-resistant,economical,safe,and environmentally friendly electrolyte is developed by utilizing water,ethylene glycol(EG),and ZnCl_(2)with high ionic conductivity(7.9 mS cm^(-1)in glass fiber membrane at-20℃).The spectra data and DFT calculations show the competitive coordination of EG and Cl-to induce a unique solvation configuration of Zn^(2+),conducive to effectively inhibiting the hydrolysis of Zn^(2+),suppressing the dendrite growth,and broadening the working voltage range and temperature range of ZnCl_(2)electrolyte.The isotope tracing data confirm that Cl^(-)could effectively destroy the ZnO passivation film,promoting the formation of Zn nuclei and improving its reaction activity.Compared to the corresponding ZnSO4electrolyte,the Cu/Zn half-cell with the ZnCl_(2)electrolyte exhibits a stable cycle life of more than 1600 h at-20℃,even at the current density of 5 mA cm^(-2).The assembled Zn-ion hybrid capacitor possesses an average capacity of 42.68 m A h g^(-1)under-20℃at a current density of 5 A g^(-1),3.5 times than that of the modified ZnSO4electrolyte.Our work proposes a new approach for optimizing aqueous electrolytes to meet low temperature energy storage applications.

High?Index?Faceted Ni_3S_2 Branch Arrays as Bifunctional Electrocatalysts for Efficient Water Splitting

For efficient electrolysis of water for hydrogen generation or other valueadded chemicals, it is highly relevant to develop low-temperature synthesis of low-cost and high-e ciency metal sulfide electrocatalysts on a large scale. Herein, we construct a new core–branch array and binder-free electrode by growing Ni_3S_2 nanoflake branches on an atomic-layer-deposited(ALD) TiO_2 skeleton. Through induced growth on the ALD-TiO_2 backbone, cross-linked Ni_3S_2 nanoflake branches with exposed { 210} highindex facets are uniformly anchored to the preformed TiO_2 core forming an integrated electrocatalyst. Such a core–branch array structure possesses large active surface area, uniform porous structure, and rich active sites of the exposed { 210 } high-index facet in the Ni_3S_2 nanoflake. Accordingly, the TiO_2@Ni_3S_2 core/branch arrays exhibit remarkable electrocatalytic activities in an alkaline medium, with lower overpotentials for both oxygen evolution reaction(220 mV at 10 mA cm^(-2)) and hydrogen evolution reaction(112 m V at 10 mA cm^(-2)), which are better than those of other Ni_3S_2 counterparts. Stable overall water splitting based on this bifunctional electrolyzer is also demonstrated.

Extended research on software hybrid testing combining reliability and directed testing

The software reliability testing has many disadvantages in practice, such as high complexity of constructing operational profiles and poor fault detection efficiency. Oppositely, the directed testing with a high fault detection rate is incapable of estimating reliability quantificationally. To solve this problem, a hybrid testing combining reliability and directed testing as well as a reliability model based on the order statistic （OS） model were presented by Mitchell. An extended research on Mitchell＇s work is proposed. Firstly, the most proper distribution of the fault＇s failure rate which tends to be Iognormal is suggested, and a detailed form of the OS model based on Iognormal and the corresponding parameter estimation method are proposed, respectively. Secondly, an im- plementing framework for the hybrid testing is proposed. Finally, the hybrid testing and the OS model are applied on a real website system. The experimental results indicate： the hybrid testing has more efficient fault detection power and lower testing cost than the reliability testing; compared with three traditional software reliabil ity growth models, the OS model has a best or pretty estimation or prediction power for each data set; and for the failure data set collected from hybrid testing, the OS model also achieves an ac- ceptable estimation result.

Correction to:High‑Index‑Faceted Ni3S2 Branch Arrays as Bifunctional Electrocatalysts for Efficient Water Splitting

In the original publication,Figure S4 is an ancillary image to compare the specific surface areas of TiO2/Ni3S2 and Ni3S2 samples and it was incorrectly published.To better serve our readers,the correct figure is provided in this correction.The BET values are correct and unaffected.The corresponding figure caption,data analysis and conclusions are not affected and thus not to be changed.The authors would like to apologize for any inconvenience caused.

Seismogenic structure of the 2016 Ms6.4 Menyuan earthquake and its effect on the Tianzhu seismic gap

On January 21, 2016, a strong earthquake with a magnitude of Ms6.4 occurred at Menyuan, Qinghai Province of China. In almost the same region, there was another strong earthquake happened in 1986, with similar magnitude and focal mechanism. Based on comprehensive analysis of regional active faults, focal mechanism solutions, precise locations of aftershocks, as well as GPS crustal deformation, we inferred that the Lenglongiing active fault dips NE rather than SW as suggested by previous studies. Considering the facts that the 2016 and i986 Ms6.4 Menyuan earthquakes are closely located with similar focal mechanisms, both of the quakes are on the north side of the Lenglongling Fault and adjacent to the fault, and the fault is dipping NE direction, we suggest that the fault should be the seismogenic structure of the two events. The Lenglongling Fault, as the western segment of the well-known Tianzhu seismic gap in the Qilian-Haiyuan active fault system, is in a relatively active state with frequent earthquakes in recent years, implying a high level of strain accumulation and a high potential of major event. It is also possible that the Lengiongiing Fault and its adjacent fault, the Jinqianghe Fault in the Tianzhu seismic gap, are rupturing simultaneously in the future.

Enhanced Redispersibility of Cellulose Nanocrystals in Water via Surface Adsorption of Hydrolyzed Sugars from Corresponding Cellulose Nanocrystal Fabrication

Generally,hydrogen bonds are formed between cellulose nanocrystals(CNCs)during their water removal and drying,leading to the irreversible aggregation of CNCs,and thus a poor water-redispersibility.The present study demonstrated a novel approach that involved using hydrolyzed sugars generated from the corresponding CNC production as redispersing agents to enhance the redispersibility of CNCs.Experimental data indicated that hydrolyzed sugars can be adsorbed onto CNCs through ethanol precipitation.The oven-dried CNCs onto which hydrolyzed sugars were adsorbed via ethanol precipitation were homogeneously redispersed in water.The redispersed CNCs showed the particle size distribution,Zeta potential,and thermal decomposition properties similar to those of the CNCs without drying.This method may improve the use of hydrolyzed sugars obtained in the hydrolysate from the corresponding CNC production,as well as facilitate the transportation and storage of CNCs.

Enhancing alkaline water oxidation with NiFe alloy-encapsulated nitrogen-doped vertical graphene array

Advancing efficient and affordable electrocatalysts to boost the oxygen evolution reaction(OER)is pivotal for sustainable green hydrogen production.Herein,we propose the fabrication of nickel-iron alloy nanoparticles-encapsulated on N-doped vertically aligned graphene array on carbon cloth(NiFe@NVG/CC)as a highly active three-dimensional(3D)catalyst electrode for OER.In 1 M KOH,such NiFe@NVG/CC demonstrates outstanding catalytic performance,necessitating merely overpotential of 245 mV for achieving a current density of 10 mA·cm^(−2),a remarkably low Tafel slope of 36.2 mV·dec^(−1).Furthermore,density functional theory calculations validate that the incorporate of N species into graphene can reinforce the electrocatalytic activity though reducing the reaction energy barrier during the conversion of*O to*OOH intermediates.The outstanding performance and structural benefits of NiFe@NVG/CC offer valuable insights for the development of innovative and efficient electrocatalysts for water oxidation.

The structure–activity relationships of Rh/CeO_(2)-ZrO_(2) catalysts based on Rh metal size effect in the three-way catalytic reactions

With the continuous tightening of automotive emission regulations and the increasing promotion of energy-efficient hybrid vehicles,new challenges have arisen for the low-temperature performance of three-way catalysts(TWCs).To guide the design of next-generation TWCs,it is essential to further develop our understanding of the relationships between microstructure and catalytic performance.Here,Rh/CeO_(2)–ZrO_(2) catalysts were synthesized with different Rh metal dispersion by using a combination of the wet impregnation method and reduction treatment.These catalysts included Rh single-atom catalysts,cluster catalysts,and nanoparticle catalysts.The results showed that the Rh nanoparticle catalyst,with an average size of 1.9 nm,exhibited superior three-way catalytic performance compared to the other catalysts.Based on the catalytic activity in a series of simple reaction atmospheres such as CO+O_(2),NO+CO,and hydrocarbons(HCs)+O_(2) and operando infrared spectroscopy,we found that metallic Rh sites on Rh nanoparticles are the key factor responsible for the low-temperature catalytic performance.

PxSy nanoparticles encapsulated in graphene as highly reversible cathode for sodium ion batteries

Herein,phosphorus-mediated sulfur nanoparticles encapsulated in reduced graphene oxide nanosheets(P-SrGO-T)were successfully synthesized as the cathode for sodium ion battery by a ball milling and the following thermal treatment.A series of covalent bonds,such as P–S,C–S–C,C–O–P and C–S–P,are formed in this process,which are in favor of fixing the sulfur and suppressing the parasitic shuttle effect of polysulfide.Benefiting from the graphene sheets and these covalent bonds,a high reversible capacity of 637.4 m Ah/g was achieved in P-SrGO-T after 100 cycles at the current density of 0.2 A/g.In addition,P-SrGO-T also delivers a high-rate capacity(330.7 m Ah/g at 5 A/g)attributing to low charge transfer resistance and faster ion diffusion kinetic.This work pushes the progress forward in developing phosphosulfide cathode for sodium ion batteries.

Carbon materials for metal-ion batteries

Metal-ion(Li-,Na-,Zn-,K-,Mg-,and Al-ion)batteries(MIBs)play an important role in realizing the goals of“emission peak and carbon neutralization”because of their green production techniques,lower pollution,high voltage,and large energy density.Carbon-based materials are indispensable for developing MIBs and are widely adopted as active or auxiliary materials in the anodes and cathodes.For example,carbon-based materials,includ-ing graphite,Si/C and hard carbon,have been used as anode materials for Li-and Na-ion batteries.Carbon can also be used as a conductive coating for cathodes,such as in LiFePO 4/C,to achieve better performance.In addition,as new high-valence MIBs(Zn-,Al-,and Mg-ion)have emerged,a growing number of novel carbon-based mate-rials have been utilized to construct high-performance MIBs.Herein,we discuss the recent development trends in advanced carbon-based materials for MIBs.The impact of the structure properties of advanced carbon-based materials on energy storage is addressed,and a perspective on their development is also proposed.

Multiple evaluations of atmospheric behavior between Criegee intermediates and HCHO: Gas-phase and air-water interface reaction

Given the high abundance of water in the atmosphere,the reaction of Criegee intermediates(CIs)with(H_(2)O)_(2) is considered to be the predominant removal pathway for CIs.However,recent experimental findings reported that the reactions of CIs with organic acids and carbonyls are faster than expected.At the same time,the interface behavior between CIs and carbonyls has not been reported so far.Here,the gas-phase and air-water interface behavior between Criegee intermediates and HCHO were explored by adopting high-level quantum chemical calculations and Born-Oppenheimer molecular dynamics(BOMD)simulations.Quantum chemical calculations evidence that the gas-phase reactions of CIs+HCHO are submerged energy or low energy barriers processes.The rate ratios speculate that the HCHO could be not only a significant tropospheric scavenger of CIs,but also an inhibitor in the oxidizing ability of CIs on SO_(x) in dry and highly polluted areas with abundant HCHO concentration.The reactions of CH_(2)OO with HCHO at the droplet’s surface follow a loop structure mechanism to produce i)SOZ(■),ii)BHMP(HOCH_(2)OOCH_(2)OH),and iii)HMHP(HOCH_(2)OOH).Considering the harsh reaction conditions between CIs and HCHO at the interface(i.e.,the two molecules must be sufficiently close to each other),the hydration of CIs is still their main atmospheric loss pathway.These results could help us get a better interpretation of the underlying CIs-aldehydes chemical processes in the global polluted urban atmospheres.

Effects of loading transition metal(Mn,Cr,Fe,Cu) oxides on oxygen storage/release properties of CeO2-ZrO2 solid solution

Cerium zirconium-based(CZ) oxygen storage materials(OSMs) play a crucial role in three-way catalysts(TWCs),while CZ needs to be modified to satisfy more rigorous emission standard.In this study,transition metal(TMs=Mn,Cr,Fe,Cu) oxides modified CZ were prepared by incipient wetness impregnation method to improve the oxygen storage capacity of CZ-based materials.To clearly illustrate the influence of TM oxides,N2 adsorption-desorption,X-ray diffraction(XRD),oxygen storage capacity(OSC),temperature programmed reduction by H2(H2-TPR) and X-ray photoelectron spectroscopy(XPS) were used to characterize the physical and chemical properties of samples.It is found that,all modified CZ have higher OSC,lower reduction temperatures than those of pristine CZ.Interaction between TMOs and CZ take precedence over specific surface to influence OSC.Notably,FeOx/CZ has the highest OSC,which is about 1.9 times that of CZ and it could be attributed to synergistic effect between FeOx and CZ;CuOx/CZ has the lowest reduction temperature which is 168℃lower than that of CZ,and it can be explained by hydrogen spillover effect.

Effect of grain size on thermal stability and oxygen storage capacity of Ce_(0.17)Zr_(0.73)La_(0.02)Nd_(0.04)Y_(0.04)O_2 solid solutions

Nanostructured CeO_2-ZrO_2 materials are an irreplaceable constituent in catalytic systems for automobile exhaust purification due to their unique oxygen storage capacity(OSC). However, traditional CeO_2-ZrO_2 materials are easy to sinter at high temperature, which causes a sharp decrease of OSC. In this paper,La^(3+) , Nd^(3+) and Y^(3+) are chosen as dopants for CeO_2-ZrO_2 to improve anti-sintering and OSC properties.The Ce_(0.17) Zr_(0.73) La_(0.02) Nd_(0.04) Y_(0.04) O_2 powders(CZLNY) were prepared by co-precipitation method. The effects of grain sizes with different mixed chlorinated solution concentrations on performances were investigated. X-ray diffraction(XRD) and transmission electron micrograph(TEM) were performed to calculate the grain sizes of CZLNY. The specific surfaces, OSC and redox properties were investigated by N_2 adsorption/desorption and temperature programmed reduction(H2-TPR). The results show that introducing La^(3+) , Nd^(3+) and Y^(3+) into CeO_2-ZrO_2 lattice can improve the stability of phase structure and anti-sintering ability. Moreover, low concentration of mixed chlorinated solution remarkably improves structural and textural properties of CZLNY. Relatively large fresh grain exhibits superior thermal stability and OSC under the condition of being calcined at 800℃ for 3 h. The specific surface and OSC are42.37 m^2/g and 333.13 mmol/g after calcining at 1000℃ for 10 h, respectively. This is owing to the low sintered driving force of large grain and long-range migration energy of large pores during the sintering process, which are beneficial to the stability of structure in CZLNY materials.

Effects of precursor moisture and inert N_2 atmosphere calcinations on structure and properties of alumina modified CeZrLaNd mixed oxides

CeO_2-ZrO_2 mixed oxides are widely used in the three-way catalysts due to their unique reversible oxygen storage and release capacity. Large surface area, high oxygen storage capacity and good thermal stability of cerium zirconium mixed oxides are the key properties for the automotive catalysts so as to meet the strict emission regulations. In this work, alumina modified CeZrLaNd mixed oxides were prepared by a co-precipitation method. The effects of moisture in precursor and inert N2 atmosphere during calcinations on the structure and properties were investigated by Brunauer-Emmett-Teller(BET) surface area measurements, X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM), hydrogen temperature-programmed reduction(H_2-TPR), oxygen storage capacity(OSC), Raman spectroscopy, and X-ray photoelectron spectroscopy(XPS). The results show that the moisture in precursor during calcinations increases the crystal grain size of the cerium zirconium mixed oxides, improving the thermal stability. And the aged surface area of sample after being calcined at1000 ℃ for 4 h reaches 68.8 m^2/g(5.7% increase compared with the common sample). The inert N2 atmosphere endows a great pore-enlarging effect, which leads to high fresh surface area of 148.9 m2/g(13.5% increase compared with the common sample) and big pore volume of 0.5705 mL/g. The redox and oxygen storage capacity are also improved by inert N2 atmosphere with high OSC value of 241.06μmolO_2/g(41.3% increase compared with the common calcination), due to the abundant formation of the crystal defects and oxygen vacancies.

Enhanced thermal stability of Ce_(0.33)Zr_(0.55)(LaNdY)_(0.12)O_(2) mixed oxides prepared by sulfate-aided coprecipitation method

Ceria-zirconia based mixed oxides(CZs)have been applied in three-way catalysts(TWCs)for their high surface area and oxygen storage capacity(OSC).In this work,enhanced thermal stability of Ce_(0.33)Zr_(0.55)(LaNdY)_(0.12)O_(2)mixed oxides was realized via a facile and scalable approach,namely,sulfateaided coprecipitation method was labelled as CZ-S.Sulfate ion(SO_(4)^(2-))was added into raw solution in the form of sulfuric acid and acted as coordination agent.The control sample was prepared by conventional coprecipitation method without sulfuric acid added and labelled as CZ.The promotion effect of sulfate ion was analyzed systematically by X-ray diffraction(XRD),transmission electron microscopy(TEM),scanning electron microscopy(SEM),N_(2)adsorption-desorption,Fourier transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),OSC and hydrogen temperatureprogrammed reduction(H_(2)-TPR)analysis.XRD and high resolution TEM results reveal that CZ-S have homogeneous distributions of elements.TEM and SEM images show that fresh samples of CZ-S have narrower distributions of grain sizes and larger pore sizes than those of CZ.Through cross analysis of structure and morphology of CZ and CZ-S,we find that the introduction of sulfate ions results in uniform distributions of elements,narrows distributions of grain sizes,and enables the formation of secondary loose packing of sub-particles,which lead to enhanced thermal stability of the samples of CZ-S upon aging process at high temperature.After aging treatment at 1100℃for 10 h,aged samples of CZ-S present larger specific surface areas and pore volumes than the aged sample prepared by conventional coprecipitation method without sulfate ions added.Furthermore,the aged sample of CZ-S2(SO_(4)^(2-)/Zr=1)possesses the highest specific surface area of 21.9 m2/g and the biggest pore volume of 0.035 mL/g among all aged samples.

SO_(4)^(2-)-modified La,Y-doped ceria-zirconia with high oxygen storage capacity and its application in Pd-only three-way catalysts

As the oxygen redox ability shows great effects on the catalytic performances of ceria-zirconia based materials,many strategies have been utilized to improve the oxygen storage capacity.Here in this study,we report a simple and facile approach to prepare a SO_(4)^(2-)-modified La,Y-doped ceria-zirconia material(SO/CZLY-f)with high oxygen storage capacity.Due to the additional redox process between SO_(4)^(2-)and S^(2-),oxygen storage capacity of SO/CZLY-f(745.3μmol O_(2)/g)is about 1.6 times higher than that of La,Ydoped ceria-zirconia material without SO_(4)^(2-)modification.Moreover,the catalytic activities and stability of the corresponding Pd-only three-way catalyst were measured.Compared to that of Pd@CZLY-f,the operation window of CO,full conversion temperature of HC and NO over Pd@SO/CZLY-f are obviously widened and lowered,respectively.After aging treatment at 1100℃for 4 h,the superiority of aged Pdloading composite is still maintained.

Extraction mechanism and separation behaviors of low-concentration Nd^(3+) and Al^(3+) in P507-H_(2)SO_(4) system

In order to clarify the solvent extraction and separation behaviors of rare earths and impurity of Al during the extraction and enrichment of low-concentration leach solution of ion-adsorption rare earth ore,the extraction mechanism and separation behaviors of Nd^(3+)and Al^(3+)in the Nd_(2)(SO_(4))_(3)-AI_(2)(SO_(4))_(3) mixed solution using P507 were studied in this work.The extraction of Nd^(3+)and Al^(3+)follows the cation exchange mechanism.With the increase of the equilibrium pH,β_(Nd/Al) in the extraction of the Nd_(2)(SO_(4))_(3)-Al_(2)(SO_(4))_(3) mixed solution using P507 is always higher than that in the extraction of single Nd_(2)(SO_(4))_(3) and Al_(2)(SO_(4))_(3) solutions.It can be attributed to the fact that the extraction of Nd^(3+)using P507 is much faster than that of Al^(3+),and Al^(3+)is more prone to be hydrolyzed at lower pH.β_(Nd/Al) in the extraction of the Nd_(2)(SO_(4))_(3)-Al_(2)(SO_(4))_(3) mixed solution decreases gradually with the increase of mixing time within the equilibrium pH range of 1.5-1.9.The extraction of Nd^(3+)using P507 is much faster than that of Al^(3+),but the stability of Al^(3+)-Ioaded organic phase is better than that of Nd^(3+)-loaded organic phase,thus Nd^(3+)in the Nd^(3+)-loaded organic phase is gradually replaced by Al^(3+)in the aqueous phase with the increase of mixing time.