Tailoring NH_(4)^(+)storage by regulating oxygen defect in ammonium vanadate

Defect engineering is an effective strategy for modifying the energy storage materials to improve their electrochemical performance.However,the impact of oxygen defect and its content on the electrochemical performances in the burgeoning aqueous NH_(4)^(+)storage field remains explored.Therefore,for the first time in this work,an oxygen-defective ammonium vanadate[(NH_(4))_(2)V_(10)O_(25)·8H_(2)O,denoted as Od-NHVO]with a novel 3D porous flower-like architecture was achieved via the reduction of thiourea in a mild reaction condition,which is a facile method that can realize the intention to regulate the oxygen defect content,with the capability of mass-production.The as-prepared Od_M-NHVO with moderate oxygen defect content can deliver a stable specific capacitance output(505 F g^(-1),252 mAh g^(-1)at 0.5 A g^(-1)with~80% capacitance retention after 10,000 cycles),which benefits from extra active sites,unimpeded NH_(4)^(+)-migration path and relatively high structure integrity.In contrast,low oxygen defect content will lead to the torpid electrochemical reaction kinetics while too high content of it will reduce the chargestorage capability and induce structural disintegration.The superior NH_(4)^(+)-storage behavior is achieved with the reversible intercalation/deintercalation process of NH_(4)^(+)accompanied by forming/breaking of hydrogen bond.As expected,the assembled flexible OdM-NHVO//PTCDI quasi-solid-state hybrid supercapacitor(FQSS HSC)also exhibits high areal capacitance,energy density and reliable flexibility.This work provides a new avenue for developing materials with oxygen-deficient structure for application in various aqueous non-metal cation storage systems.

In situ confined vertical growth of Co_(2.5)Ni_(0.5)Si_(2)O_(5)(OH)_(4)nanoarrays on rGO for an efficient oxygen evolution reaction

Rational design of oxygen evolution reaction(OER)catalysts at low cost would greatly benefit the economy.Taking advantage of earth-abundant elements Si,Co and Ni,we produce a unique-structure where cobalt-nickel silicate hydroxide[Co_(2.5)Ni_(0.5)Si_(2)O_(5)(OH)_(4)]is vertically grown on a reduced graphene oxide(rGO)support(CNS@rGO).This is developed as a low-cost and prospective OER catalyst.Compared to cobalt or nickel silicate hydroxide@rGO(CS@rGO and NS@rGO,respectively)nanoarrays,the bimetal CNS@rGO nanoarray exhibits impressive OER performance with an overpotential of 307 mV@10 mA cm^(-2).This value is higher than that of CS@rGO and NS@rGO.The CNS@rGO nanoarray has an overpotential of 446 mV@100 mA cm^(-2),about 1.4 times that of the commercial RuO_(2)electrocatalyst.The achieved OER activity is superior to the state-of-the-art metal oxides/hydroxides and their derivatives.The vertically grown nanostructure and optimized metal-support electronic interactions play an indispensable role for OER performance improvement,including a fast electron transfer pathway,short proton/electron diffusion distance,more active metal centers,as well as optimized dualatomic electron density.Taking advantage of interlay chemical regulation and the in-situ growth method,the advanced-structural CNS@rGO nanoarrays provide a new horizon to the rational and flexible design of efficient and promising OER electrocatalysts.

Quench-tailored Al-doped V_(2)O_(5) nanomaterials for efficient aqueous zinc-ion batteries

Rechargeable aqueous zinc-ion batteries(ZIBs)are regarded as a promising competition to lithium-ion batteries as energy storage devices,owing to their high safety and low cost.However,the development of high-performance ZIBs is largely hindered by the shortage of ideal cathode materials with high-rate capability and long-cycle stability.Herein,we address this bottleneck issue by the quenching-tailored surface chemistry of V_(2)O_(5) cathode nanomaterial.By rapid quenching from high temperatures,Al ions are doped into V_(2)O_(5) lattice(Al-V_(2)O_(5))and abundant oxygen vacancies are formed on the surface/nearsurface,which facilitate the desired rapid electron transfers.Our density functional theory(DFT)simulations elucidate that the doping of Al ions into V_(2)O_(5) remarkably reduces the Zn^(2+)-diffusion barriers and improves the electrical conductivity of V_(2)O_(5).As a proof-of-concept application,the thus-optimized AlV_(2)O_(5) cathode delivers a superior specific capacity of 532 m Ah g^(-1) at 0.1 A g^(-1) and a long-cycling life with76%capacity retention after 5000 cycles,as well as a good rate performance.This work provides not only a novel strategy for tuning the surface chemistry of V_(2)O_(5) to boost the Zn^(2+)storage but also a general pathway of modifying metal oxides with improved electrochemical performance.

Quality Characteristics and FTIR Research of Amorphophallus konjac K. Koch Cultivated under Forest

[Objectives]This study aimed to evaluate the quality characteristics of Amorphophallus konjac K.Koch and study the tubers of A.konjac K.Koch by infrared spectroscopy and second derivative method.[Methods]Referring to industrial standards of China for agriculture and related documents,the quality characteristics of A.konjac K.Koch were determined;and using potassium bromide tableting method and Fourier transform infrared spectroscopy,the infrared spectrum and second derivative spectrum of A.konjac K.Koch were studied.[Results]The drying rate,total ash content,acid-insoluble ash content,water extract content,ethanol extract content and crude polysaccharide content of A.konjac K.Koch were above 14.00%,4.57%-11.78%,0.04%-4.87%,26.31%-36.98%,2.20%-7.95%and 40.25%-61.18%,respectively.The infrared spectra of A.konjac K.Koch of different origins were relatively close,and the differences were mainly in peak intensity.The peaks at 1642,1322,1241,1154,1022,863,770 and 576 cm-1 were the main specific peaks.The main component was konjac glucomannan.[Conclusions]FTIR technology is simple and quick,and is suitable for quality control and sample identification of A.konjac K.Koch.This provides a scientific basis for the quality control and comprehensive utilization of A.konjac K.Koch cultivated under forest.

Identification of Motor Nuclei in the Medulla Oblongata of Carp for Biological Control

Brain-controlled technology is the key technology in biological control,and the corresponding relationship between animal brain nuclei and motor behavior is the core.The purpose of this study was to explore the motor nuclei of the medulla oblongata in carp.The carps were subjected to electrical stimulation and chemical stimulation experiments,respectively,in the water-free state,and the effective chemical stimulation sites were injected with the pontamine sky blue solution.The brain tissue sections were obtained by paraffin tissue section technology and the neutral red staining method.By comparing the positions of the brain nuclei shown in earlier studies,the motor nerve nuclei in the medulla oblongata were identified.The brain electrode was implanted into the motor nucleus of the medulla oblongata,and the underwater control experiment and behavioral tests were carried out with different electrical stimulation parameters.The results showed that the abducens nucleus(NVI)was the motor nucleus that controls the ipsilateral steering,and the facial nucleus(NVII)was the motor nucleus that controls the forward movement.By adjusting the stimulation voltage and the stimulation pulse number,the carp can be stably controlled to achieve a left–right steering motion of 30°–180°and a forward motion of more than 80 cm/s.This study indicated that the quantitative control of the steering and forward behavior of the carp can be achieved by electrical stimulation of the NVI and NVII,which provided a certain experimental basis for the accurate control of the carp robot.

Adjusting oxygen vacancy of VO_(2)·xH_(2)O nanoarray architectures for efficient NH_(4)^(+) storage

Aqueous rechargeable batteries are the promising energy storge technology due to their safety,low cost,and environmental friendliness.Ammonium ion(NH_(4)^(+))is an ideal charge carrier for such batteries because of its small hydration radius and low molar mass.In this study,VO_(2)·xH_(2)O with rich oxygen defects(d-HVO)is designed and synthesized,and it exhibits unique nanoarray structure and good electrochemical performances for NH_(4)^(+)storge.Experimental and calculation results indicate that oxygen defects in d-HVO can enhance the conductivity and diffusion rate of NH_(4)^(+),leading to improved electrochemical performances.The most significant improvement is observed in d-HVO with 2 mmol thiourea(d-HVO-2)(220 mAh·g^(-1) at 0.1 A·g^(-1)),which has a moderate defect content.A full cell is assembled using d-HVO-2 as the anode and polyaniline(PANI)as the cathode,which shows excellent cycling stability with a capacity retention rate of 80%after 1000 cycles and outstanding power density up to 4540 W·kg^(-1).Moreover,the flexible d-HVO-2||PANI battery,based on quasi-solid electrolyte,shows excellent flexibility under different bending conditions.This study provides a new approach for designing and developing high-performance NH_(4)^(+)storage electrode materials.

Intermetallic ferric nickel silicide alloy derived from magadiite by magnesiothermic reaction as bifunctional electrocatalyst for overall water splitting

As the cleanest energy source,hydrogen energy is regarded as the most promising fuel.Water electrolysis,as the primary means of hydrogen production,has constantly been the focus of attention in the energy conversion field.Developing eco-friendly,cheap,safe and efficient catalysts for electrochemical water splitting(EWS)is the key challenge.Herein,the intermetallic silicide alloy is first synthesized via a facile magnesiothermic reduction and employed as bifunctional electrocatalysts for EWS.Ferric-nickel silicide(denoted as FeNiSi)alloy is designed and shows a good electrocatalytic performance for EWS.The lattice distortions of FeNiSi enhance the electrocatalytic activity.Besides,the porous structure affords more active sites and improves the reaction kinetics.As a consequence,FeNiSi delivers an excellent performance with overpotential of 308 mV for oxygen evolution reaction(OER)and 386 mV for hydrogen evolution reaction(HER)at 10 mA·cm−2 in 1 M KOH.The stability structure of intermetallic silicide achieves an outstanding durability with an unchanged potential of 1.66 V for overall water splitting at 10 mA·cm−2 for 15 h.This work not only provides a facile method for the synthesis of intermetallic silicide with considerable porous structures,but also develops the potential of intermetallic silicide alloy as bifunctional electrocatalysts for EWS,which opens up a new avenue for the design and application of intermetallic silicide alloy.

B-lymphoid tyrosine kinase-mediated FAM83A phosphorylation elevates pancreatic tumorigenesis through interacting with β-catenin

Abnormal activation of Wnt/β-catenin-mediated transcription is closely associated with the malignancy of pancreatic cancer.Family with sequence similarity 83 member A(FAM83A)was shown recently to have oncogenic effects in a variety of cancer types,but the biological roles and molecular mechanisms of FAM83A in pancreatic cancer need further investigation.Here,we newly discovered that FAM83A binds directly toβ-catenin and inhibits the assembly of the cytoplasmic destruction complex thus inhibiting the subsequent phosphorylation and degradation.FAM83A is mainly phosphorylated by the SRC non-receptor kinase family member BLK(B-lymphoid tyrosine kinase)at tyrosine 138 residue within the DUF1669 domain that mediates the FAM83A-β-catenin interaction.Moreover,FAM83A tyrosine 138 phosphorylation enhances oncogenic Wnt/β-catenin-mediated transcription through promotingβ-catenin-TCF4 interaction and showed an elevated nucleus translocation,which inhibits the recruitment of histone deacetylases by TCF4.We also showed that FAM83A is a direct downstream target of Wnt/β-catenin signaling and correlates with the levels of Wnt target genes in human clinical pancreatic cancer tissues.Notably,the inhibitory peptides that target the FAM83A-β-catenin interaction significantly suppressed pancreatic cancer growth and metastasis in vitro and in vivo.Our results revealed that blocking the FAM83A cascade signaling defines a therapeutic target in human pancreatic cancer.

Flexible quasi-solid-state zinc-ion hybrid supercapacitor based on carbon cloths displays ultrahigh areal capacitance

Over the past few years,the flexible quasi-solid-state zinc-ion hybrid supercapacitors(FQSS ZHSCs)have been found to be ideal for wearable electronics applications due to their high areal capacitance and energy density.The assembly of desirable ZHSCs devices that have promising practical applications is of high importance,whereas it is still challenging to assemble ZHSCs devices.In this study,a ZHSC that exhibited ultrahigh areal capacitance and high stability was developed by using an active carbon cloth(ACC)cathode,which could improve ionic adsorption.The as-obtained ACC cathode had an energy storage mechanism due to the electrical double-layer capacitive behavior of Zn^(2+),which was accompanied by the dissolution/deposition of Zn_(4)SO_(4)(OH)6·5H2O.The ACC//Zn@ACC ZHSC device exhibited an areal capacitance of 2437 mF cm^(−2)(81 F cm^(−3),203 F g^(-1) under the mass of ACC with∼12 mg cm^(−2))at 1 mA cm^(−2),an areal energy density of 1.354 mWh cm^(−2) at 1 mW cm^(−2),as well as high stability(with an insignificant capacitance decline after 20000 cycles),which was demonstrated to outperform the existing ZHSCs.Furthermore,the assembled flexible device still had competitive capacitance,energy density and service life when integrated into a FQSS ZHSC.When applied in practice,the device could achieve high mechanical flexibility,wearable stability and output.This study can inspire the development of the FQSS ZHSC device to satisfy the demands for wearable energy storage devices with high performance.

Synergistic effect of K^(+)and PANI in vanadium oxide hydration by interlayer engineering boosts the ammonium ion storage

Aqueous ammonium-ion(NH_(4)^(+))hybrid supercapacitor(AA-HSC),as a new type of energy storage device with great potential,is in the initial stage of rapid development.Based on its special energy storage mechanism,exploiting novel NH_(4)^(+)-hostingmaterials is still a great challenge.Herein,vanadium oxide hydration(VOH)tuned by interlayer engineering of K+/PANI co-intercalation,named KVO/PANI,is designed for AA-HSC.Intercalated PANI can shield interaction between NH_(4)^(+)and V–O layers to some extent and enlarge interlayer space,which improves the efficiency of reversible NH_(4)^(+)(de)insertion.However,K+enhances redox activity and electronic conductivity.The synergistic effect of co-intercalation optimizes intercalation pseudocapacitive behavior during the(de)ammonization process,which is reported in NH_(4)^(+)storage for the first time.Theoretical calculations reveal that the lowered electron transport barrier and enhanced electronic conductivity improveNH_(4)^(+)kinetics and exhibit high capacitance for charge storage.The KVO/PANI can deliver the specific capacitance of 340 F g^(−1) at 0.5 A g^(−1) and retain 177 F g^(−1) at 10 A g^(−1).Pairing with activated carbon,the AA-HSC can achieve a decent energy density of 31.8 Wh kg^(−1).This work gives inorganic/organic co-intercalation that can enhance the NH_(4)^(+)storage of VOH by interlayer engineering.The strategy can be used to design other materials for aqueous energy storage systems.

PVA-assisted hydrated vanadium pentoxide/reduced graphene oxide films for excellent Li^(+)and Zn^(2+)storage properties

Low-cost,high safety and environment-friendly aqueous energy storage systems(ESSs)are huge potential for grid-level energy storage,but the(de)intercalation of metal ions in the electrode materials(e.g.vanadium oxides)to obtain superior long-term cycling stability is a significant challenge.Herein,we demonstrate that polyvinyl alcohol(PVA)-assisted hydrated vanadium pentoxide/reduced graphene oxide(V_(2)O_(5)·n H_(2)O/r GO/PVA,denoted as the VGP)films enable long cycle stability and high capacity for the Li^(+)and Zn^(2+)storages in both the VGP//Li Cl(aq)//VGP and the VGP//Zn SO4(aq)//Zn cells.The binderfree VGP films are synthesized by a one-step hydrothermal method combination with the filtration.The extensive hydrogen bonds are formed among PVA,GO and H_(2)O,and they act as structural pillars and connect the adjacent layers as glue,which contributes to the ultrahigh specific capacitance and ultralong cyclic performance of Li^(+)and Zn^(2+)storage properties.As for Li^(+)storage,the binder-free VGP4 film(4mg PVA)electrode achieves the highest specific capacitance up to 1381 F g^(-1)at 1.0 A g^(-1)in the three-electrode system and 962 F g^(-1)at 1.0 A g^(-1)in the symmetric two-electrode system.It also behaves the outstanding cyclic performance with the capacitance retention of 96.5%after 15000 cycles in the three-electrode system and 99.7%after 25000 cycles in the symmetric two-electrode system.As for Zn^(2+)storage,the binder-free VGP4 film electrode exhibits the high specific capacity of 184 m A h g^(-1)at 0.5A g^(-1)in the VGP4//Zn SO4(aq)//Zn cell and the superb cycle performance of 98.5%after 25000 cycles.This work not only provides a new strategy for the construction of vanadium oxides composites and demonstrates the potential application of PVA-assisted binder-free film with excellent electrochemical properties,but also extends to construct other potential electrode materials for metal ion storage cells.