Ionic Conduction in Ba0.95Ce0.8Ho0.2O3-α

Ba0.95Ce0.8Ho0.2O3-a was prepared by high temperature solid-state reaction. X-ray diffraction （XRD） pattern showed that the material was of a single perovskite-type orthorhombic phase. Using the material as solid electrolyte and porous platinum as electrodes, the measurements of ionic transport number and conductivity of Ba0.95Ce0.8Ho0.2O3-a were performed by gas concentration cell and ac impedance spectroscopy methods in the temperature range of 600---1000 ℃in wet hydrogen, dry and wet air respectively. Ionic conduction of the material was investigated and compared with that of BaCe0.8Ho0.2O3-a. The results indicated that Ba0.95Ce0.8Ho0.2O3-a was a pure protonic conductor with the protonic transport number of 1 during 600---700℃ in wet hydrogen, a mixed conductor of protons and electrons with the protonic transport number of 0.97--0.93 in 800---1000 ℃. But BaCe0.8Ho0.2O3-a was almost a pure protonic conductor with the protonic transport number of 1 in 600---900 ℃ and 0.99 at 1000 ℃ in wet hydrogen. In dry air and in the temperature range of 600---1000 ℃, they were both mixed conductors of oxide ions and electronic holes, and the oxide-ionic transport numbers were 0.24--0.33 and 0.17--0.30 respectively. In wet air and in the temperature range of 600---1000 ℃, they were both mixed conductors of protons, oxide ions and electronic holes, the protonic transport numbers were 0.11--0.00 and 0.09--0.01 respectively, and the oxide-ionic transport numbers were 0.41--0.33 and 0.27--0.30 respectively. Protonic conductivity of Ba0.95Ce0.8Ho0.2O3-a in both wet hydrogen and wet air was higher than that of BaCe0.8Ho0.2O3-a in 600--- 800 ℃, but lower in 900--1000 ℃. Oxide-ionic conductivity of the material was higher than that of BaCe0.8Ho0.2O3-a in both dry air and wet air in 600---1000 ℃.     

BaCe0.8Ho0.2O3-a陶瓷的性质与应用

Ceramic BaCe0.8Ho0.2O3-α with orthorhombic perovskite structure was prepared by conventional solid state reaction, and its conductivity and ionic transport number were measured by ac impedance spectroscopy and gas concentration cell methods in the temperature range of 600-1000 ℃ in wet hydrogen and wet air, respectively. Using the ceramics as solid electrolyte and porous platinum as electrodes, the hydrogen-air fuel cell was constructed, and the cell performance at temperature from 600-1000 ℃ was examined. The results indicate that the specimen was a pure protonic conductor with the protonic transport number of 1 at temperature from 600-900 ℃ in wet hydrogen, a mixed conductor of proton and electron with the protonic transport number of 0.99 at 1000 ℃. The electronic conduction could be neglected in this case, thus the total conductivity in wet hydrogen was approximately regarded as protonic conductivity. In wet air, the specimen was a mixed conductor of proton, oxide ion and electron hole. The protonic transport numbers were 0.01-0.09, and the oxide-ionic transport numbers were 0.27-0.32. The oxide ionic conductivity was increased with the increase of temperature, but the protonic conductivity displayed a maximum at 900 ℃, due to the combined increase in mobility and depletion of the carriers. The fuel cell could work stably. At 1000 ℃, the maximum short-circuit current density and power output density were 346 mA/cm^2 and 80 mW/cm^2, respectively.     

Editorial

<正>After centuries endeavor of human,materials have become one of the most important instruments in human society.In the past several decades,materials for energy storage and transformation,electronic devices,and biological applications have gained rapid development.For instance,electronic wearable devices,which is one of the product of smart technological evolution,could be     

Novel SrCe_(0.75)Zr_(0.20)Tm_(0.05)O_(3-δ) membrane for hydrogen separation

<正>Dense ceramic membranes with protonic and electronic conductivity have attracted considerable interest in recent years.In this paper,the powders of SrCe_(0.75)Zr_(0.20)Tm_(0.05)O_(3-δ) were synthesized via the liquid citrate method,and the membranes of SrCe_(0.75)Zr_(0.20)Tm_(0.05)O_(3-δ) were prepared by pressing followed by sintering.X-ray diffraction(XRD) was used to characterize the phase structure of both the powder and sintered membrane.The microstructure of the sintered membranes was studied by scanning electron microscopy(SEM).Hydrogen permeation through the SrCe_(0.75)Zr_(0.20)Tm_(0.05)O_(3-δ) membranes was carried out using gas permeation setup at 900℃.Hydrogen permeation flux of SrCe_(0.75)Zr_(0.20)Tm_(0.05)O_(3-δ) membrane reaches up to 0.042 mL/ min cm~2 at H_2 partial pressure of 0.4 atm.The hydrogen permeation fluxes obtained in this paper are similar to that of SrCe_(0.95)Tm_(0.05)O_(3-δ),and Zr doping can increase mechanical strength of SrCe_(0.75)Zr_(0.20)Tm_(0.05)O_(3-δ) membranes and the resistance to reducing circumstance.     

一维链状铽配位聚合物｛[Tb(p-MBA)_2(H_2O)_2]_2·(4,4′-bipy)_2｝_n的合成、晶体结构及荧光分析(英文)

People have long been interested in the coordination polymers of terbium! with carboxylic acids for those polymers often have peculiar structure and luminescent feature. They can be used as extraction and separation agents, bactericides, luminescent and functional materials. For example, they are used in the production of plastic membranes, lighting materials, developing materials and ornament materials[1～3]. In chemical literature, we can find many research reports about ternary complexes of…     

Synthesis and Spectroscopic Investigation of Azoporphyrins

Recently the synthesis of the porphyrins and the investigation of their physico-chemical properties have been of increasing interest.In particular,well-designed porphyrin derivatives can act as switches and gates1,nonlinear optics2and other organic photoelectric materials3,4.In these fields the investigation of photoinduced electron transfer is essential in understanding the mechanism and processes of these molecular scale electronic components.Azobenzene and some azobenzene derivatives could …     

Oxidations of two-dimensional semiconductors: Fundamentals and applications

Since the discovery of graphene, two-dimensional(2D) semiconductors have been attracted intensive interest due to their unique properties. They have exhibited potential applications in next generation electronic and optoelectronic devices. However, most of the 2D semiconductor are known to suffer from the ambient oxidation which degrade the materials and therefore hinder us from the intrinsic materials’ properties and the optimized performance of devices. In this review, we summarize the recent ...     

Strain of 2D materials via substrate engineering

Two-dimensional(2D) materials have received extensive attention in the fields of electronics, optoelectronics, and magnetic devices attributed to their unique electronic structures and physical properties. The application of strain is a simple and effective strategy to change the lattice structure of 2D materials thus modulating their physical properties, which further facilitate their applications in carrier mobility transistor, magnetic sensor, single-photon emitter etc. In this short review, ...     

Tuning the electronic structure of the earth-abundant electrocatalysts for oxygen evolution reaction(OER)to achieve efficient alkaline water splitting-A review

Tuning the electronic structure of the electrocatalysts for oxygen evolution reaction(OER)is a promising way to achieve efficient alkaline water splitting for clean energy production(H2).At first,this paper introduces the significance of the tuning of electronic structure,where modifying the electronic structure of the electrocatalysts could generate active sites having optimal adsorption energy with OER intermediates,and that could diminish the energy barrier for OER,and that could improve the activity for OER.Later,this paper reviews the tuning of electronic structure along with catalytic performances,synthetic methodologies,chemical properties,and DFT calculations on various nanostructured earth-abundant electrocatalysts for OER in alkaline environment.Further,this review discusses the tuning of the electronic structure of the several nanostructured earth-abundant electrocatalysts including oxide,(oxy)hydroxide,layered double hydroxide,alloy,metal phosphide/phosphate,nitride,sulfide,selenide,carbon containing materials,MOF,core-shell/hetero/hollow structured materials,and materials with vacancies/defects for OER in alkaline environment(including activity:overpotential(η)of ≤200 mV at10 m A cm^-2;stability:≥100 h;durability:≥5000 cycles).Then,this review discusses the robust stability of the electrocatalysts for OER towards practical application.Moreover,this review discusses the in situ formation of thin layer on the catalyst surface during OER.In addition,this review discusses the influence of the adsorption energy of the OER intermediates on OER performance of the catalysts.Finally,this review summarizes the various promising strategies for tuning the electronic structure of the electrocatalysts to achieve enhanced performance for OER in alkaline environment.     

Recent progress on discovery and properties prediction of energy materials:Simple machine learning meets complex quantum chemistry

In nature,the properties of matter are ultimately governed by the electronic structures.Quantum chemistry(QC)at electronic level matches well with a few simple physical assumptions in solving simple problems.To date,machine learning(ML)algorithm has been migrated to this field to simplify calculations and improve fidelity.This review introduces the basic information on universal electron structures of emerging energy materials and ML algorithms involved in the prediction of material properties.Then,the structure-property relationships based on ML algorithm and QC theory are reviewed.Especially,the summary of recently reported applications on classifying crystal structure,modeling electronic structure,optimizing experimental method,and predicting performance is provided.Last,an outlook on ML assisted QC calculation towards identifying emerging energy materials is also presented.     

Hydrothermal Synthesis and Crystal Structure of a Hybrid Compound Based on β-Octamolybdate [Mn(2,2’-bipy)_3]_2[β-Mo_8O_(26)]·4H_2O

1 INTRODUCTION Polyoxometalates (POMs) are one of the most widely used inorganic components due to their at- tractive electronic and molecular properties with va- rious applications in catalysis, medicine, materials science[1～3] and so on. Exploration of transition me- tal complex cations as well as organic component which functions as ligand as building blocks in the construction of metal oxide composite materials is a fruitful strategy[4, 5]. Among the polyoxometalates studied to dat…     

Synthesis and Crystal Structure of (1-Naphthyl){[3- (2,6-dibromo-4-methylphenylimino)methyl]-5-chloro- 2-hydroxy-benzaldehyde}(triphenylphosphine) Nickel(II) Triphenylphosphine

1INTRODUCTION Over the past decades,olefin oligomerization and polymerization based on late transition metal catalysts have been the most exciting developments in the area of organometallic chemistry and polymer science[1～3].In this broad context,neutral nickel(II)complexes have attracted much attention for their less sensitivity to protonic solvents and polar mon-mers.The most typical one is the SHOP-type cata-lyst[4～6],which contains an anionic[P,O]chelate ring and shows high activ…     

The impact of regiochemistry of conjugated molecules on the performance of organic electronic devices

Organic photovoltaics and field-effect transistors have attracted considerable attention due to the easy fabrication,low cost,light weight,and flexibility.Unsymmetrical conjugated building blocks are widely utilized for the design of new organic π-functional materials in order to achieve high-performance electronic devices,which has become a hot research topic in recent years.In this review,we summarized some typical organic π-functional materials with regioregular conjugated backbones with unsymmetrical electron-deficiency moieties and focused on the influence of regiochemistry on the final device performance.     

ELECTRONIC STRUCTURE AND CHEMICAL BONDING OF BIS(TRIMETHYLSILYL)AMIDE DERIVATIVES OF LANTHANIDES(Ln(N(SiMe_3)_2)_3, Ln=Nd, Eu, Yb)

The electronic structure and chemical bonding of Ln(N(SiMe_3)_2)_3 have been studied by INDO calcula-tions. The results have shown that the Ln-N bonds are considerably covalent in character and that thecovalency decreases with increasing atomic numbers. A new explanation of the pyramidal structure of thecompounds has been proposed based on 5d orbital participation in bonding. With the calculation of asimplified model of Eu(N(SiMe_3)_2)_3. OPPh_3, the roles of electronic and steric effects in bonding have beencompared.     

Synthesis and Photoelectrical Properties of D-A Type Carbazole-quinoline

The key issues concerning the design and synthesis of high fluorescent efficiency, good thermal stability of organic blue materials should be solved urgently in organic light emitting diodes. In this article, three D-A type blue emitters based on carbazole and phenylquinoline with flexible chains were prepared through Friedlander condensation reaction in relatively high yield. The photoelectric properties of all compounds were studied by UV-vis absorption, emission spectra and cyclic voltammograms. Density functional theory calculations(DFT) were performed to obtain a better understanding of the electronic structures. Interestingly, compound a3 with the highest fluorescence quantum yield of 0.53 can be applied into blue light emission materials on account of good thermal performance. Furthermore, a1～a3 with narrow band gap make them become potential candidates in the fields of OLED, solar cells and OFET.     

Recent advances of dithienobenzodithiophene-based organic semiconductors for organic electronics

In recent years, fused aromatic dithienobenzodithiophene(DTBDT)-based functional semiconductors have been potential candidates for organic electronics. Due to the favorable features of excellent planarity, strong crystallinity, high mobility, and so on, DTBDT-based semiconductors have demonstrated remarkable performance in organic electronic devices, such as organic feld-effect transistor(OFET), organic photovoltaic(OPV), organic photodetectors(OPDs). Driven by this success, recent developments in the area of DTBDT-based semiconductors for applications in electronic devices are reviewed, focusing on OFET, OPV, perovskite solar cells(PSCs), and other organic electronic devices with a discussion of the relationship between molecular structure and device performance. Finally, the remaining challenges, and the key research direction in the near future are proposed, which provide a useful guidance for the design of DTBDT-based materials.     

Synthesis and Crystal Structure of Bis-(2,2'''' bipyridyl)-2-pyrimidinethiolate-Ni(Ⅱ) Complex

1 INTRODUCTION The design of metal complexes of bipyridine is one of the most highlighting topics in molecular materials with specific optical, electronic and mag- netic properties. What studied and well-documented most widely are those of the d6 metal polypyridines, and so are the d8 and d10 metal complexes with rich luminescence behaviour[1] very recently, which can be beneficial to the design of unique functional ma- terials. Currently our interest is to design lumine- scent heteronuc…     

Role of self-assembly in construction of inorganic nanostructural materials

Understanding the evolution process and formation mechanism of nanoscale structures is crucial to controllable synthesis of inorganic nanomaterials with well-defined geometries and unique functionalities. In addition to the conventional Ostwald ripening process, oriented aggregation has been recently found to be prevalent in nanocrystal growth. In this new mechanism, primary small nanocrystals firstly spontaneously aggregate in the manner of oriented attachment, and then the large crystalline materials are formed via the process of interparticle recrystallization. Furthermore, controllable fabrication of the ordered nanocrystal solid materials that has shown specific collective properties will promote the application of inorganic nanocrystal in devices. Therefore, investigation of the mechanism of oriented aggregation is essential to controllable synthesis of nanocrystals and ordered nanocrystal solid materials. In this review, we summarize recent advances in the preparation of nanocrystal materials, which are mostly focused on our work about the role of self-assembly in construction of inorganic nanostructural materials.     

THE FRONTIER ORBITALS OF BUCKMINSTERFULLERENE C_(60)

The frontier orbitals HOMO and LUMO of the fullerene C_(60) hasbeen given in a system of 60 motion-coordinates, of which each origin is ateach C atom of fullerene C_(60) and each z-axis is in the directionperpendicular to C_(60)'S spherical surface. In this motion-coordinate systemthe HOMO and LUMO of fullerene C_(60) obviously display characteristics ofspherical n-molecular orbitals π_n. The Fenske-Hall quantum-chemical methodis used in calculation for the electronic structure of the fullerene C_(60).     

Synthesis,Crystal Structure,and Spectral Properties of a Novel Co(II) Complex Containing Imidazole Derivative

1 INTRODUCTION The metal-organic frameworks constructed from metals and π-conjugated ligands might have poten- tial applications in various fields, such as electronic, optical or magnetic materials[1～3]. Therefore, this kind of complex has attracted the increasing atten- tion of chemists, and considerable efforts have been devoted to the rational design and synthesis of new materials[4, 5]. Moreover, the organic-inorganic hybri- dized coordination complexes with imidazole deri- vatives …