F-doped orthorhombic Nb_(2)O_(5) exposed with 97% (100) facet for fast reversible Liþ-Intercalation

Orthorhombic Nb_(2)O_(5)(T-Nb_(2)O_(5))is attractive for fast-charging Li-ion batteries,but it is still hard to realize rapid charge transfer kinetics for Li-ion storage.Herein,F-doped T-Nb_(2)O_(5) microflowers(F-Nb_(2)O_(5))are rationally synthesized through topotactic conversion.Specifically,F-Nb_(2)O_(5) are assembled by single-crystal nanoflakes with nearly 97%exposed(100)facet,which maximizes the exposure of the feasible Li^(+)transport pathways along loosely packed 4g atomic layers to the electrolytes,thus effectively enhancing the Li^(+)-intercalation performance.Besides,the band gap of F-Nb_(2)O_(5) is reduced to 2.87 eV due to the doping of F atoms,leading to enhanced electrical conductivity.The synergetic effects between tailored exposed crystal facets,F-doping,and ultrathin building blocks,speed up the Li^(+)/electron transfer kinetics and improve the pseudocapacitive properties of F-Nb_(2)O_(5).Therefore,F-Nb_(2)O_(5) exhibit superior rate capability(210.8 and 164.9 mAh g^(-1) at 1 and 10 C,respectively)and good long-term 10 C cycling performance(132.7 mAh g^(-1) after 1500 cycles).

Tungsten carbide-reduced graphene oxide intercalation compound as co-catalyst for methanol oxidation

Highly dispersed tungsten carbide（WC） nanoparticles（NPs） sandwiched between few-layer reduced graphene oxide（RGO） have been successfully synthesized by using thiourea as an anchoring and inducing reagent.The metatungstate ion,[H2W（12）O（40）]^6-,is assembled on thiourea-modified graphene oxide（GO） by an impregnation method.The WC NPs,with a mean diameter of 1.5 nm,are obtained through a process whereby ammonium metatungstate first turns to WS2,which then forms an intercalation compound with RGO before growing,in situ,to WC NPs.The Pt/WC-RGO electrocatalysts are fabricated by a microwave-assisted method.The intimate contacts between Pt,WC,and RGO are confirmed by X-ray diffraction,scanning electron microscope,transmission electron microscope,and Raman spectroscopy.For methanol oxidation,the Pt/WC-RGO electrocatalyst exhibited an electrochemical surface area value of 246.1 m^2/g Pt and a peak current density of1364.7 mA/mg Pt,which are,respectively,3.66 and 4.77 times greater than those of commercial Pt/C electrocatalyst（67.2 m^2/g Pt,286.0 mA/mg Pt）.The excellent CO-poisoning resistance and long-term stability of the electrocatalyst are also evidenced by CO stripping,chronoamperometry,and accelerated durability testing.Because Pt/WC-RGO has higher catalytic activity compared with that of commercial Pt/C,as a result of its intercalated structure and synergistic effect,less Pt will be required for the same performance,which in turn will reduce the cost of the fuel cell.The present method is facile,efficient,and scalable for mass production of the nanomaterials.

Preparation and Properties of Phenolic Resin/Montmorillonite Intercalation Nanocomposites

Phenolic resin/montmorillonite intercalation composites were prepared by using the methods of pressing intercalation and melt intercalation.Properties and structure of the composites were investigated by using XRD,TG and test of softening point.It is indicated that both the pressing intercalation and melt intercalation can be used to prepare the phenolic resin/organo-montmorillonite intercalation nanocomposites.Compared with phenolic resin,the intercalation nanocomposites have better heat-resistance,higher decomposition temperatures and less thermal weight-loss.However,these two intercalation methods have different effects on the softening point of the intercalation nanocomposites.Pressing intercalation almost does not affect the softening point of the intercalation nanocomposites,while melt intercalation significantly increases the softening point of the intercalation nanocomposites, probably due to the chemical actions happening in the process of melt intercalation.

Intercalation Assembly Method and Intercalation Process Control of Layered Intercalated Functional Materials

Layered intercalated functional materials of layered double hydroxide type are an important class of functional materials developed in recent years. Based on long term studies on these materials in the State Key Laboratory of Chemical Resource Engineering in Beiiing University of Chemical Technology, the orinciole for the design of controlled intercalation processes in the light of tuture production processing requirements has been developed. Intercalation assembly methods and technologies have been invented to control the intercalation process for preparing layered intercalated materials with various structures and functions.

Intercalation of metals and silicon at the interface of epitaxial graphene and its substrates

Intercalations of metals and silicon between epitaxial graphene and its substrates are reviewed. For metal intercala- tion, seven different metals have been successfully intercalated at the interface of graphene/Ru（O001） and form different intercalated structures. Meanwhile, graphene maintains its original high quality after the intercalation and shows features of weakened interaction with the substrate. For silicon intercalation, two systems, graphene on Ru（O001） and on Ir（l I 1）, have been investigated. In both cases, graphene preserves its high quality and regains its original superlative properties after the silicon intercalation. More importantly, we demonstrate that thicker silicon layers can be intercalated at the interface, which allows the atomic control of the distance between graphene and the metal substrates. These results show the great potential of the intercalation method as a non-damaging approach to decouple epitaxial graphene from its substrates and even form a dielectric layer for future electronic applications.

Physical Blocking Neural Tube Closure Affects Radial Intercalation and Neural Crest Midline-directed Migration in Xenopus Dorsal Explants

Neural tube defects （NTDs） are severe congenital malformation diseases, which occur in 1 out of 1000 births in human. In Xenopus, several tissue movements are involved in the neural tube closure process. Immediately after the neural tube fusion, the neural crest cells get monopolar protrusion toward dorsal midline and migrate to form the roof of the neural tube. At the same time, radial intercalation takes place from the ventral neural tube and forces it to be single-layered. Here, we physically block the neural tube closure to test the cell movements and the following patterning in Xenopus laevis explants. The results show that the single-layered neural tube fails to form and the neural crest cells remain at the lateral regions in the explants with NTDs. However, the patterning of the neural tube is not affected as indicated by the normal expression of the preneural genes. These results indicate a requirement of the neural tube fusion for the radial intercalation and the dorsal midline directed neural crest migration, but not for the dorsal-ventral patterning of the neural tube.

Lithium intercalation/de-intercalation behavior of a composite Sn/C thin film fabricated by magnetron sputtering

A tin film of 320 nm in thickness on Cu foil and its composite film with graphite of-50 nm in thickness on it were fabricated by magnetron sputtering. The surface morphology, composition, surface distributions of alloy elements, and lithium intercalation/de-intercalation behaviors of the fabricated films were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, electron probe microanalyzer （EPMA）, X-ray photoelectron spectroscopy （XPS）, inductively coupled plasma atomic emission spectrometry （ICP）, cyclic voltammetry （CV）, and galvanostatic charge/discharge （GC） measurements. It is found that the lithium intercalation/de-intercalation behavior of the Sn film can be significantly improved by its composite with graphite. With cycling, the discharge capacity of the Sn film without composite changes from 570 mAh/g of the 2nd cycle to 270 mAh/g of the 20th cycle, and its efficiency for the discharge and charge is between 90% and 95%. Nevertheless, the discharge capacity of the composite Sn/C film changes from 575 mAh/g of the 2nd cycle to 515 mAh/g of the 20th cycle, and its efficiency for the discharge and charge is between 95% and 100%. The performance improvement of tin by its composite with graphite is ascribed to the retardation of the bulk tin cracking from volume change during lithium intercalation and de-intercalation, which leads to the pulverization of tin.

STUDY ON INTERCALATION MECHANISM OF GELATIN/MMT NANOCOMPOSITE

A gelatin/MMT nanocomposite was prepared in an aqueous solution and investigated by XRD,FTIR and 13 C NMR,and then the intercalation mechanism was discussed.The result of XRD indicated that the gelatin molecule had already inserted into the interlayer of MMT,and the intercalation or exfoliation structure had been achieved.The result of 13 C NMR demonstrated that the ions interaction between gelatin and MMT was attributed to the driving force for intercalation.In order to confirm the role of -COO - of gelatin in the combination with MMT,lauric sodium was brought in as a model to react with MMT,and was characterized by XRD and FTIR,the result proved that there existed a kind of strong interaction between -COO - and ions of MMT.

K+alkalization promoted Ca2+intercalation in V2CTx MXene for enhanced Li storage

Although MXenes is highly attractive as anode materials of lithium ion batteries,it sets a bottleneck for higher capacity of the V2CTxMXene due to the limited interlayer space and the derived surface terminations.Herein,the cation intercalation and ion-exchange were well employed to achieve a K+and Ca2+intercalated V2CTxMXene.A larger interlayer distance and low F surface terminations were thereof obtained,which accelerates the ion transport and promotes the delicate surface of V2CTx MXene.As a result,a package of enhanced capacity,rate performance and cyclability can be achieved.Furthermore,the ion exchange approach can be extended to other 2 D layered materials,and both the interlayer control and the surface modification will be achieved.

Influence of blasting on the properties of weak intercalation of a layered rock slope

A precondition for correctly analyzing the stability of a slope and designing its bracing structure is to study and determine the influence of excavation blasting on the properties of weak intercalation in the layered rock slope. On the basis of in-situ stratification-cracking blasting tests, the properties of weak intercalation were investigated using the LS-DYNA3D program. The displacement distribution and compactness of weak intercalation at different positions away from the charge center and their various laws are discussed. The critical displacement of stratification-cracking （0.1 mm） was obtained, and an approximate expression of compactness were deduced. Furthermore, through the simulation of a layered rock blasting under the same geological conditions, the stratification-cracking effect of deep-hole blasting on the properties of weak intercalation was compared with that of short-hole blasting, and the influencing differences, in addition to their causes, were analyzed. The results indicated that the blasting cavity of weak intercalation in short-hole blasting with a radius of 40 mm was nearly a circle, whose radius was about 28.7 cm; whereas in deep-hole blasting with a radius of 150 mm, the shape of the blasting cavity was different from that in short-hole blasting, the radius of the cavity behind the charge （89.1 cm） was further smaller than those of the other three （138.7 cm）, and there were sharp crinkles on the surface of weak intercalation. When the distance from the charge center （DCC） was less than 40 and 150 cm in short-hole and deep-hole blasting, respectively, the displacement of weak intercalation was reduced remarkably with the increase in DCC.

Influences of Li Intercalation on the Electronic Structures of O2p and V3d Orbitals in α-V205

The influence of Li intercalation on the electronic structures of oxygen and vanadium ions in α-V205 was investigated using first-principles calculations based on the density functional theory with local density approximation. Two different intercalation sites for Li in the V205 lattices were considered. The calculation results demonstrate that intercalated Li ions at different sites show different effects on the electronic structures of O2p and V3d orbitals. But in both cases Li intercalation will weaken the V---O1 bonding and cause the split-off in V3d valence band to narrow or even disappear and simultaneously broaden the O2p conduction band. Further, the average electron transfer number from per intercalated Li2s to V3d orbitals is determined to total be about 0.52.

Li intercalation in an MoSe_(2) electrocatalyst:In situ observation and modulation of its precisely controllable phase engineering for a high-performance flexible Li-S battery

Sophisticated efficient electrocatalysts are essential to rectifying the shuttle effect and realizing the high performance of flexible lithium-sulfur batteries(LSBs).Phase transformation of MoSe_(2) from the 2H phase to the 1T phase has been proven to be a significant method to improve the catalytic activity.However,precisely controllable phase engineering of MoSe_(2) has rarely been reported.Herein,by in situ Li ions intercalation in MoSe_(2),a precisely controllable phase evolution from 2H-MoSe_(2) to 1T-MoSe_(2) was realized.More importantly,the definite functional relationship between cut-off voltage and phase structure was first identified for phase engineering through in situ observation and modulation methods.The sulfur host(CNFs/1T-MoSe_(2))presents high charge density,strong polysulfides adsorption,and catalytic kinetics.Moreover,Li-S cells based on it display capacity retention of 875.3mAh g^(-1) after 500 cycles at 1 C and an areal capacity of 8.71mAh cm^(-2) even at a high sulfur loading of 8.47mg cm^(-2).Furthermore,the flexible pouch cell exhibiting decent performance will endow a promising potential in the wearable energy storage field.This study proposes an effective strategy to precisely control the phase structure of MoSe_(2),which may provide the reference to fabricate the highly efficient electrocatalysts for LSBs and other energy systems.

Preparation and Structural Investigation of CuCl_2 Graphite Intercalation Compounds

Superfine graphite powder was prepared by ball-milling exfoliated graphite containing anhydrous CuCl2 in planetary ball milling systems. Nano-scale CuCl2 graphite intercalation compounds were synthesized by heating a mixture of anhydrous CuCl2 and graphite nanosheets. Scanning electron microscopy, energy-dispersive X-ray spectroscopy and high-resolution transmission electron microscopy were performed to characterize the microstructures of stage-1 nano-scale CuCl2 graphite intercalation compounds. The structure and components of the domain wall and core in the nano-scale CuCl2 graphite intercalation compounds are described. The results show that the content of CuCl2 in the mixture plays a crucial role in the size of the nano-scale CuCl2 graphite intercalation compound.

Design of Wood/Montmorillonite (MMT) Intercalation Nanocomposite

Studying new wood composites through nano science and technology (NSC) will develop new compounding theory of wood, and accelerate the combination of new technology, wood science, material science and other disciplines. The compounding of wood and inorganic MMT on nanoscale molecular level has high potential to greatly improve the mechanical properties, fire retardance, abrasion resistance, decay resistance, dimensional stability and other properties of wood. Based on the great achievements of polymer/montmorillonite (MMT) nanocomposites, this paper reviewed nano intercalation compounding methods (i.e. in-situ intercalative polymerization and direct polymer intercalation), and discussed the structure, properties and modification of montmorillonite (MMT). According to the main chemical components and particular structure of wood, the authors discussed the liquefaction and plasticization of wood, compared the dissolvability and meltability between wood and polymer, and then systematically put forward the basic idea, technological processes and schematic diagram to prepare wood/MMT nanocomposites (WMNC). The key technology to prepare WMNC is either to introduce delaminated MMT nanolayers into wood with the help of some intermediate polymers, or to obtain liquefied wood or plasticized wood from the complicated natural composite. It is applicable and effective to realize wood/MMT nanoscale compounding with the help of proper intercalation agent and medium polymer through the proposed 搊ne-step?or 搕wo-step?impregnating processes.

Intercalation engineering of layered vanadyl phosphates for high performance zinc-ion batteries

Aqueous zinc-ion batteries(ZIBs) have attracted great attention as the candidates for large-scale energy storage system,recently,because of their low cost,environment-friendly,high safety,and high theoretical energy densities.Among the numerous cathode materials,layered structure vanadium based polyanionic compounds,such as VOPO_(4),exhibit high specific capacity for Zn ion storage.However,the low Zn ion diffusion coefficient and limited interlayer spacing make the cathodes low reversible capacity and inferior cycling stability.Herein,K ions were pre-intercalated into the VOPO_(4) layers via ions exchange adopting VOPO_(4)·2 H_(2) O as the precursor.When evaluated as the cathode for ZIBs,an excellent cycle stability of 400 cycles under a current density of 500 mA g^(-1) was achieved by the obtained KVOPO_(4) electrode,verifying the positive effect of intercalation engineering.Furtherly,a solid-solution reaction Zn ion storage mechanism was confirmed.This study provides a new insight to explore high performance cathode materials for ZIBs.

Intercalation Assembly, Characterization and Luminescent Properties of Novel Supramolecular Composite Materials, Tb(Ⅲ) Complex with Tetrapodal Ligand-Montmorillonite

Two kinds of Tb（ Ⅲ ） complexes with tetrapodal ligand, [TbL（NO3）]^3＋ and [TbL]^3＋ （L： 1,1, 1＇, 1＇-tera （ 2-pyridinecarboxylester ）-di （ trimethylpropane）） were intercalated into the interlayer space of montmorillonite （MT） by ion exchange and coordination reaction of L with the Tb^3＋ ion existing in the interlayer space of Tb-MT respectively. The obtained luminescent supramolecular composite materials, [ TbL （NO3） ]^2＋-MT and [TbL]^3＋-MT were characterized by elemental analysis, XRD, FT-IR, UV-vis and thermal analysis. At the same time, the luminescent properties of the materials were also studied. The results show that the intercalated materials with regular layered structure, good thermal stability and the interlayer spacing （d001） approximates to the size of the complex ions which are located in the interlayer space of MT in the form of a monolayer.

Etching-courtesy NH_(4)^(+) pre-intercalation enables highly-efficient Li^(+) storage of MXenes via the renaissance of interlayer redox

Inspired by a well-known architecture notion that load-bearing walls enable maintaining a highly-stable multiple-floored building,superior advantages are afforded via fabricating the NH_(4)+ions pre-intercalated Mo_(2)CT_(x) MXene(Mo_(2)CT_(x)-N)in a mixed solution of NH_(4)F and HCl via a simple one-step hydrothermal method.As a result of the synergistic effects of pillared structure,immobilizing-F groups and unlocking Mo-based redox,the Mo_(2)CT_(x)-N remarkably delivered a reversible capacity of 384.6 mAh ^(g-1) at 200 mA g^(-1) after 100 cycles.Our work lays a foundation for fully packaging its optimal performance via carding and architecting the chemistry of the MXene layers and between them.

Melting Intercalation Method to Prepare Lauric Acid/Organophilic Montmorillonite Shape-stabilized Phase Change Material

A kind of novel shape-stabilized phase change material （SSPCM） was prepared by using a melting intercalation technique. This kind of SSPCM was made of lauric acid （LA） as a phase change material and organophilic montmorillonite （OMMT） as a support material. And the thermal properties and morphology of the SSPCM were characterized by X-ray diffraction （XRD）, transmission electron microscope （TEM）, scanning electronic microscope （SEM）, scanning calorimeter （DSC）, and differential thermal cravimetry （TG）. The DSC result shows that the phase change temperature of the SSPCM is close to that of LA, and its latent heat is equivalent to that of the calculated value based on the mass ratio of LA measured by TG. The XRD, SEM and TEM results demonstrate that the LA intercalates into the silicate layers of the OMMT, thus forming a typically intercalted hybrid, which can restrict the molecular chain of the LA within the structure of OMMT at high temperature. And consequently SSPCM can keep its solid state during its solid-liquid phase change processing.

Preparation and Photochemical Behavior of a Cationic Azobenzene Dye-Montmorillonite Intercalation Compound

Montmorillonite/cationic azobenzene dye（p-（δ-triethylammoniobutoxy）-p＇-methyl- azobenzene bromide） intercalation compounds were prepared by the conventional ion exchange method. As compared with that of pure cationic azo-dye, the thermal stability of the intercalated dye was greatly enhanced, and the absorption band corresponding to azobenzene group in intercalated dye shifted towards longer wave length by 38 nm. This could be ascribed to the strong conjugation of cationic azo-dye supramolecular order structure（J cluster） confined in a nanoscale space of montmorillonite interlayer gallery. UV/vis spectra data show that the intercalated azo dye in the montmorillonite interlayer space exhibited reversible trans-to-cis photoisomerization and daylight cis-to-trans back reaction. FTIR indicates the successful intercalation of cationic azo-dye into the montmorillonite interlayer.

Electrical Properties of Expanded Graphite Intercalation Compounds

The intercalation compounds of CuCl2 were synthesized with expanded graphite, whose magnitude of the electrical conductivity is about 10(3)S(.)cm(-1). Their electrical conductivity is 3 similar to6 times as high as that of the expanded graphite, and about 10 times as high as that of GIC made of the non-expanded graphite. The microanalysis results of chemical compounds by X-ray energy spectrum scanning of TEM testified that the atomic ratio of chloride and cupric is nonstoichoimetric. The multivalence and exchange of electrovalence of the cupric ion was confirmed by the XPS-ESCA. Vacancy of chlorine anion increases the concentration of charge carrier. The special stage structure, made of graphite and chloride, produces a weak chemical bond belt and provides a carrier space in the direction of GIC layer. These factors develop the electrical properties.