Molybdenum Oxynitride Atomic Nanoclusters Bonded in Nanosheets of N-Doped Carbon Hierarchical Microspheres for Efficient Sodium Storage

Transition metal nitrides have attracted considerable attention as great potential anode materials due to their excellent metallic conductivity and high theoretical specific capacity.However,their cycling performance is impeded by their instability caused by the reaction mechanism.Herein,we report the engineering and synthesis of a novel hybrid architecture composed of MoO2.0N0.5 atomic nanoclusters bonded in nanosheets of N-doped carbon hierarchical hollow microspheres(MoO2.0N0.5/NC)as an anode material for sodium-ion batteries.The facile self-templating strategy for the synthesis of MoO2.0N0.5/NC involves chemical polymerization and subsequent one-step calcination treatments.The design is benefi-cial to improve the electrochemical kinetics,buffer the volume variation of electrodes during cycling,and provide more interfacial active sites for sodium uptake.Due to these unique structural and compositional merits,these MoO2.0N0.5/NC exhibits excellent sodium storage performance in terms of superior rate capability and stable long cycle life.The work shows a feasible and effective way to design novel host candidates and solve the long-term cycling stability issues for sodium-ion batteries.

Synthesis and Characterization of Mesoporous Silicon Oxynitride MCM-41 with High Nitrogen Content

Mesoporous silicon oxynitrides MCM-41 were synthesized successfully. The resulting materials not only have high nitrogen contents and good structural characteristics of MCM-41 (high surface area, narrow pore size distribution and good order), but also are amorphous. The composition and structure of the materials were investigated by CNH element analysis, XPS, Si MAS NMR, XRD, HRTEM and N-2 sorption, respectively. Mesoporous silicon oxynitrides MCM-41 with a high nitrogen content are still non-crystal (amorphous).

Valence modulated nickel oxynitride network as integrated bifunctional electrodes for enhanced energy storage

As promising electrode materials,transition metal oxides have attracted considerable attention owing to their excellent performance in electrochemical energy storage.However,their poor conductivity and fragile structure limit their practical application.In this study,a binder-free nickel oxide/oxynitride network(NiON WS)bifunctional electrodes with cation multivalent states that exhibit high energy storage performance were synthesized for the first time.The massive active sites,high specific surface areas,and multiple cation valence states of NiON WS were advantageous for electrochemical redox reaction during its application in supercapacitors(1283.5 mF cm^(-2))and lithium-ion batteries(1345.0 mA h g^(-1)).Particularly,the NiON WS based flexible asymmetric SCs exhibit excellent capacitance and energy densities.First-principle calculations were employed to study the mechanism of the electrochemical performance improvement of NiON WS.This study demonstrates the potential of transition metal oxides electrode with high capacity and activity for electrochemical energy storage and conversion.

Influence of Silicon Oxynitride on Slag Resistance of Al_2O_3-Si C-C Refractory

Silicon oxynitride was added in shaped Al_2O_3-SiC-C refractory material to improve the slag resistance in this paper.Optimum adding quantity of silicon oxynitride powder was also studied. The results show that the slag resistance of Al_2O_3-SiC-C shaped refractory is improved when 2% or 3% Si_2N_2O is added. A reasonable amount of Si_2N_2O added into Al_2O_3-Si C-C shaped refractory can produce silicon oxide into the slag, which can improve the viscosity of slag and prevent the slag erosion and penetration.

Synthesis and Characterization of Vanadium Molybdenum Oxynitrides Nanoparticles in the Channels of MCM-41

Vanadium molybdenum oxynitrides nanoparticles were synthesized successfully in the channels of MCM-41 after surface modification,vacumm co-impregnation and nitridation technology.The products were investigated by nitrogen sorption measurement,X-ray powder diffraction（XRD）,high-resolution transmission electron microscopy（HRTEM）,energy dispersive analysis of X-rays（EDAX）and CNH element analysis.The investigation resnlts show that superfine nanoparticles of vanadium molybderum oxynitrides exist in the channels of MCM-41.

Intense Yellow Photoluminescence from Silicon Oxynitride Films Prepared by Dual Ion Beam Sputtering

In this work, results on the study of the structure and photoluminescence (PL) properties of SiOxNy thin films are presented. The films were deposited at room temperature using a dual-ion-beam co-sputtering system. The XRD and TEM results show that the deposited films have an amorphous structure. In the XPS result, we find N 1s spectra consist of one symmetric single peak at 397.8 eV, indicating that the nitrogen atoms are mainly bonded to silicon. It is in agreement to the result of FTIR. In SiOxNy films, an intense single PL peak at 590 nm is observed. Furthermore, with the increase of the N content in the SiOxNy films, the intensity of the PL peak at 590 nm increases a lot. The PL peak of 590 nm is suggested to originate from N-related defects.

Characterisation of Zinc Oxynitride Thin Films Prepared Using Zinc(II) Complex of Hexamethylenetetramine as the Precursor

A Zinc(II) complex of hexamethylenetetramine was prepared as a single source precursor and used to deposit zinc oxynitride thin films. The thin films were deposited on soda-lime glass substrates using the Metal Organic Chemical Vapour Deposition (MOCVD) technique at the deposition temperature of 370°C and 390°C, respectively. The Fourier Transform Infrared Spectroscopy (FTIR) was used to determine the functional groups in the precursor, with stretching frequency for O-H, N-H, and C-H observed. The deposited films were characterized using UV-Visible Spectroscopy, Scanning Electron Microscopy (SEM), Elemental diffraction X-ray (EDX), and X-ray Diffractometer (XRD). A direct bandgap of 3.15 eV and 3.18 eV was obtained from the film deposited at 370°C and 390°C, respectively, using the Envelope Method. In comparison, a bandgap of 3.19 eV and 3.21 eV was obtained using the absorption spectrum fitting (ASF) method. The SEM revealed that the film is homogeneous, dense, and compact, composed of cluster grains. The EDX confirmed the presence of Zinc, Nitrogen and Oxygen. The X-ray Diffraction indicated the polycrystalline nature of the film.

Properties of Titanium Oxynitride Prepared by RF Plasma

Titanium oxynitrides combine the properties of metallic oxides and nitrides. In this presentation, titanium was oxynitrided using inductively coupled RF plasma in a gas mixture containing 80% N2 and 20% O2. The effect of plasma-processing power from 350 up to 550 W on microstructure, mechanical, tribological, wettability and electrochemical properties of the oxynitrided titanium was examined using different characterizations and testing techniques. The results demonstrated the formation of TiO, TiO2 rutile phase, TiNxOy and Ti2N as a result of plasma oxynitriding. The micro-hardness of the oxynitrided layers increases up to 766 HV0.1 as the plasma-processing power increases up to 550 W. The wear and corrosion resistance are improved for oxynitrided titanium in comparison with untreated samples. Moreover, the friction coefficient decreases from nearly 0.75 for the pure titanium to nearly 0.3 for oxynitrided titanium. The obtained data show an increase of surface energy and wettability of titanium oxynitride as the plasma power increases. The formation of hard oxide and oxynitride phases and the transformation of TiO2 from anatase to rutile structure at relatively high temperature are the main reasons for the good physical and electrochemical properties of titanium oxynitride.

Solid-state corrosion of lithium for prelithiation of SiO_(x)-C composite anode with carbon-incorporated lithium phosphorus oxynitride

In order to address the issues of low initial Coulombic efficiency of SiO_(x)-C composite anode due to the formation of solid electrolyte interphase,irreversible conversion reaction,and large volume change,the prelithiation method using metal lithium has been employed as one of effective solutions.However,violent side reactions with liquid electrolyte for prelithiation lead to low prelithiation efficiency and induce poor interface between the SiO_(x)-C electrode and liquid electrolyte.Here,a new prelithiation method with so called solid-state corrosion of lithium is developed.By replacing liquid electrolyte with solid-state electrolyte of carbon-incorporated lithium phosphorus oxynitride(LiCPON),not only various side reactions associated with metal lithium are avoided,but also the perfect interface is achieved from the decomposition products of LiCPON.The successful implementation of solid-state corrosion prelithiation can be confirmed by changes in optical image,scanning electron microscopy,and X-ray diffraction.Compared with pristine electrode,the initial Coulombic efficiency of the prelithiated electrode using solid electrolyte can be increased by about 10%,reaching 98.6%in half cell and 88.9%in full cell.Compared with prelithiated electrode using liquid electrolyte,the prelithiation efficiency of the prelithiated anode with solid-state corrosion can be increased from 25.7%to 82.8%.Solid-state corrosion of lithium is expected to become a useful method for prelithiation of SiO_(x)-C composite electrode with high initial Coulombic efficiency and large prelithiation efficiency.

Dendrite-free all-solid-state lithium batteries with lithium phosphorous oxynitride-modified lithium metal anode and composite solid electrolytes

Dendrite formation on lithium (Li) metal anode is a key issue which hinders the development of rechargeable Li battery seriously. A novel method for suppress!ng Li dendrites via using Li phosphorous oxynitride (UPON) modified Li anode and Li1.5Al0.5Ge1.5(PO4)3-poly(ethylene oxide)(Li bistrifluoromethane-sulfonimide)(LAGP-PEO(LiTFSI)) composite solid electrolyte in all-solid-state Li battery is proposed, and the effect of the thickness of UPON on Li anode performarice is also studied. LiPON film with a thickness of 500 nm exhibits satisfactory interface property between Li metal anode and the LAGP-PEO(LiTFSI) solid electrolyte. The LiPON film provides a uniform Li^+ flux across the interface and effectively inhibits the formation of Li dendrites in all-solid-state Li batteries. The assembled all-solid-state Li cell Li(LiPON)/LAGP-PEO(LiTFSI)/LiFePO4 delivers an initial discharge capacity of 152.4 mAh·g^-1 and exhibits good cycling stability and rate performanee at 50 ℃.

Structural,Wettability and Optical Investigation of Titanium Oxynitride Coatings:Effect of Various Sputtering Parameters

The objective of the present work is to investigate the effect of various sputtering parameters such as nitrogen flow rate, deposition time and sputtering pressure on structural, wettability and optical properties of titanium oxynitride films deposited on glass substrate by reactive magnetron sputtering. The X-ray diffraction graphs of titanium oxynitride films show evolution of various textures of TiO=N and TiN phases with increasing nitrogen flow rate and deposition time, but an increase in sputtering pressure from 4.0 to 8.0 Pa results in decline of various textures observed for TiO=Ny and TiN phases. The stress and strain calculated by sin2~ method are compressive, which decrease with increasing nitrogen flow rate from 55 to I00 sccm （standard cubic centimeter per minute） and increase with increasing deposition time from 80 to I40 min due to atomic penning effect and increasing thickness of the deposited films. The titanium oxynitride films have contact angle values above 90 deg., indicating that films are hydrophobic. The maximum contact angle of I09.1 deg. is observed at deposition time of 140 min. This water repellent property can add value to potential protective, wear and corrosion resistant application of titanium oxynitride films. The band gap decreases from 1.98 to 1.83 eV as nitrogen flow rate is increased from 55 to 100 sccm; it decreases from 1.93 to 1.79 eV as deposition time is increased from 80 to 140 min as more nitrogen incorporation results in higher negative potential of valence band N2p orbital. But it increases from 2.26 to 2.34 eV for titanium oxynitride films as sputtering pressure increases from 4.0 to 8.0 Pa.

Photoluminescent properties of tunable green-emitting oxynitride （Baa-xSrx）Si6012N2 ：Eu2＋ phosphor and its application in white LEDs

Green emitting Eu2＋-doped （Ba3_xSrx）Si6012N2 solid solutions were synthesized through solid state reaction at 1350 ℃ for 10 h under a N2/H2 atmosphere. The XRD patterns revealed that the solid solution series of （Ba3 x-ySrx）Si6Ol2N2：yEu2＋ with x value ranging from 0-0.6 were established. An efficient and intense tunable green light was observed by varying the cation Sr/Ba ratio. The emission spectra exhibited an entire shift towards long wavelength with increasing ofx value, which was caused by large crystal field splitting and Stokes shift. The x value dependence of emission intensity was discovered and explained by the enhanced probability of electron from excited 4f state to 5d ground state via nonradioactive transition. Highly thermal stability and feasible color coordinates were verified. White LEDs with excellent photochromic properties were fabricated by packing GaN based blue chips and （Ba Sr）3Si6012N2：Eu2＋ phosphors. All results indicated that the （Ba3_xSrx）SirO12N2：Eu2＋ phosphors were confirmed to be a promising candidate for pc-white LEDs in solid state lighting.

Effect of fluxes on synthesis and luminescence properties of BaSi_2O_2N_2:Eu^(2+) oxynitride phosphors

Eu^2＋ activated BaSi2 O2 N2 oxynitride bluish-green phosphor was synthesized adopting conventional high-temperature solid-state reaction method, in which BaF2, Na2 CO3 and NH4 Cl were used as the fluxes.The phase formation, size distribution and microscopic morphology were characterized to investigate the influence of adding fluxes on photo luminescence properties. The results indicate that with the addition of BaF2 flux, the particle morphology becomes regular and size distribution narrows and the phase purity of BaSi2 O2 N2：Eu^2＋ phosphor can be improved effectively. The photoluminescence intensity of BaSi2 O2 N2：Eu^2＋ phosphor with BaF2 as flux gets enhanced obviously, which is much higher than that of Na2 CO3, NH4 Cl and without flux. The optimum content of BaF2 flux is 4 wt%, and the maximum photoluminescence intensity of the BaSi2 O2 N2：Eu^2＋ phosphor prepared with BaF2 flux rises to 141%,meanwhile, the phosphors with BaF2 flux exhibits low thermal quenching. The results indicate that the BaSi2 O2 N2：Eu^2＋ is sort of promising bluish-green phosphor for application in full-spectra LED.

Water-soluble boron carbon oxynitride dots with excellent solid-state fluorescence and ultralong room-temperature phosphorescence

Developing metal-free and long lifetime room-temperature phosphorescence(RTP)materials has received tremendous interest due to their numerous potential applications,of which stable triplet-excited state is the core challenge.Here,boron carbon oxynitride(BCNO)dots,emitting stable blue fluorescence and green RTP,are reported for the first time.The obtained BCNO dots exhibit an unexpected ultralong RTP lifetime of 1.57 s,lasting over 8 s to naked eyes.The effective doping of carbon and oxygen elements in boron nitride(BN)actually provides a small energy gap between singlet and triplet states,facilitating the intersystem crossing(ISC)and populating of triplet excitons.The formation of compact cores via crystallization and effective inter-/intra-dot hydrogen bonds further stabilizes the excited triplet states and reduces quenching of RTP by oxygen at room temperature.Based on the water-soluble feature of BCNO dots,a novel advanced security ink is developed toward anti-counterfeiting tag and confidential information encryption.This study extends BCNO dots to rarely exploited phosphorescence fields and also provides a facile strategy to prepare ultralong lifetime metal-free RTP materials.

Enhanced polysulfide redox kinetics by niobium oxynitrides via insitu adsorptive and catalytic effect in wide temperature range

The development of Li-S batteries(LSBs)is hindered by the low utilization of S species and sluggish redox reaction kinetics.Polar metal oxides always possess high adsorption to polar S species,while conductive metal nitrides show fast electron transport and ensure fast redox reaction of S species.The combination merits of metal oxides and metal nitrides in one provide an effective strategy to improve the electrochemical performance of LSBs.In this work,defect design of niobium oxynitrides highly dispersed on graphene(NbON-G)is evaluated as effective trapper and catalyst for S species.Owning to the effective structural merits including enriched active sites,alleviated volume variation,defect modulated electronic property,and in-situ chemisorption and catalytic conversion of soluble lithium polysulfides(LiPSs),the LSBs with NbON-G modified separator show remarkably enhanced performance compared to NbN-G and Nb_(2)O_(5)-G.Surprisingly,even at low temperature of−40°C,the LSBs with NbON-G can operate for 1,000 cycles with 0.04%capacity decay per cycle(Rate:2 C).

Effect of oxygen concentration on resistive switching behavior in silicon oxynitride film

SiOxNy films with different oxygen concentrations were fabricated by reactive magnetron sputtering,and the resistive switching characteristics and conduction mechanism of Cu/SiOxNy/ITO devices were investigated.The Cu/SiOxNy/ITO device with SiOxNy deposited in 0.8-sccm O2 flow shows a reliable resistive switching behavior,including good endurance and retention properties.As the conductivity of SiOxNy increases with the increase of the oxygen content dynamical electron trapping and detrapping is suggested to be the conduction mechanism.The temperature dependent I-V measurement indicates that the carrier transport can be ascribed to the hopping conduction rather than the metallic conductive filament.

Photoluminescence and thermal quenching properties of tunable green-emitting oxynitride (Ca_xSr_(1–x))_6Si_(25.6)Al_(6.4)N_(41.6)O_(4.4):Eu^(2+) phosphors

Green emitting Eu^2＋ doped（CaxSr（1–x））6Si（25.6）Al（6.4）N（41.6）O（4.4） phosphors with x value ranging from 0 to 0.1 were synthesized by the solid state reaction method under nitrogen atmosphere.The X-ray diffraction（XRD）patterns of the phosphors with different Ca^2＋ concentrations indicated that pure sialon phases were obtained.Crystal structure of these sialon phases was estimated to be a commensurate composite network stacking by two different types of layers.Intense and tunable green emissions with a slight red shift from 515 to 520 nm were observed with varying Ca/Sr ratios.The emission intensity decreased gradually because of the increase of the crystal splitting effect.Thermal quenching properties of the phosphors with different Ca^2＋ saturation were also discussed.The thermal stability became worse as more Ca^2＋ ions substituted for Sr^2＋ ions according to a larger Stokes shift.The solid solution phosphors could be a promising candidate for white LEDs for their interesting photoluminescence properties when the thermal stability would be improved.

All-Solid-State Thin-Film Lithium-Sulfur Batteries

Lithium-sulfur(Li-S)system coupled with thin-film solid electrolyte as a novel high-energy micro-battery has enormous potential for complementing embedded energy harvesters to enable the autonomy of the Internet of Things microdevice.However,the volatility in high vacuum and intrinsic sluggish kinetics of S hinder researchers from empirically integrating it into allsolid-state thin-film batteries,leading to inexperience in fabricating all-solid-state thin-film Li-S batteries(TFLSBs).Herein,for the first time,TFLSBs have been successfully constructed by stacking vertical graphene nanosheets-Li2S(VGsLi2S)composite thin-film cathode,lithium-phosphorous-oxynitride(LiPON)thin-film solid electrolyte,and Li metal anode.Fundamentally eliminating Lipolysulfide shuttle effect and maintaining a stable VGs-Li2S/LiPON interface upon prolonged cycles have been well identified by employing the solid-state Li-S system with an“unlimited Li”reservoir,which exhibits excellent longterm cycling stability with a capacity retention of 81%for 3,000 cycles,and an exceptional high temperature tolerance up to 60℃.More impressively,VGs-Li2S-based TFLSBs with evaporated-Li thin-film anode also demonstrate outstanding cycling performance over 500 cycles with a high Coulombic efficiency of 99.71%.Collectively,this study presents a new development strategy for secure and high-performance rechargeable all-solid-state thin-film batteries.

In situ reaction mechanism of MgAlON in Al–Al2O3–MgO composites at 1700°C under flowing N2

The Al–AlO–MgO composites with added aluminum contents of approximately 0wt%, 5wt%, and 10wt%, named as M, M, and M, respectively, were prepared at 1700°C for 5 h under a flowing Natmosphere using the reaction sintering method. After sintering, the Al–AlO–MgO composites were characterized and analyzed by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The results show that specimen Mwas composed of MgO and MgAlO. Compared with specimen M, specimens Mand Mpossessed MgAlON, and its production increased with increasing aluminum addition. Under an Natmosphere, MgO, AlO, and Al in the matrix of specimens Mand Mreacted to form MgAlON and AlN-polytypoids, which combined the particles and the matrix together and imparted the Al–AlO–MgO composites with a dense structure. The mechanism of MgAlON synthesis is described as follows. Under an Natmosphere, the partial pressure of oxygen is quite low; thus, when the Al–AlO–MgO composites were soaked at 580°C for an extended period, aluminum metal was transformed into AlN. With increasing temperature, AlOdiffused into AlN crystal lattices and formed AlN-polytypoids; however, MgO reacted with AlOto form MgAlO. When the temperature was greater than(1640 ± 10)°C, AlN diffused into AlOand formed spinel-structured AlON. In situ MgAlON was acquired through a solid-solution reaction between AlON and Mg AlOat high temperatures because of their similar spinel structures.

Microwave Assisted Sintering and Photoluminescence Properties of BaaSi6OleNe：Eu^2＋ Green Phosphors

Eu^2＋-doped Ba3Si6012N2 green phosphors were prepared by microwave assisted sintering method at 1275℃ for 4 h, while the counterparts using conventional solid-state reaction method were synthesized at temperature higher than 1300℃ and for to 10 h. Microwave assisted sintering could reduce the activation energy and enhance the diffu- sion rate, thus greatly improved the sintering. Moreover, the influence of Si3N4 content on phase formation, morphol- ogy, absorption, and quantum efficiency, and photoluminescence properties of phosphors were studied. As a result, the Ba3Si6OI2N2：Eu^2＋ samples sintered by microwave assisted sintering method have a higher phase purity and photo- luminescence intensity under ultraviolet excitation as compared with samples sintered in the conventional tube furnace The proposed method is a potential preparation method for the oxynitride phosphors with strong photoluminescence and high phase purity.