Titanium Aluminides: Science, Technology, Applications and Synthesis by Mechanical Alloying

The production. characteristics. and commercialization of monolithic and composite titanium aluminides are summanzed with emphasis on use in the demanding aerospace industry. The attractive elevated temperature properties combined with alow density make these materials of great interest, but inherently low 'forgiveness', and environmental concerns, must be overcome before widespread use will occur One synthesis method for the production of monolithic titanium aluminides-mechanical alloying- will be discussed in detail

Nitrogen-doped graphene:Synthesis,characterizations and energy applications

Nitrogen-doped（N-doped） graphene has attracted increasing attentions because of the significantly enhanced properties in physic, chemistry, biology and material science, as compared with those of pristine graphene. By date, N-doped graphene has opened up an exciting new field in the science and technology of two-dimensional materials. From the viewpoints of chemistry and materials, this article presents an overview on the recent progress of N-doped graphene, including the typical synthesis methods, characterization techniques, and various applications in energy fields. The challenges and perspective of Ndoped graphene are also discussed. We expect that this review will provide new insights into the further development and practical applications of N-doped graphene.

Synthesis and application of single-atom catalysts in sulfur cathode for high-performance lithium–sulfur batteries

Lithium–sulfur(Li-S)batteries are regarded as one of the most promising energy storage devices because of their low cost,high energy density,and environmental friendliness.However,Li-S batteries suffer from sluggish reaction kinetics and serious“shuttle effect”of lithium polysulfides(LiPSs),which causes rapid decay of battery capacity and prevent their practical application.To address these problems,introducing single-atom catalysts(SACs)is an effective method to improve the electrochemical performance of Li-S batteries,due to their high catalytic efficiency and definite active sites for LiPSs.In this paper,we summarized the latest developments in enhancing the electrochemical performance of cathode for Li-S batteries through introducing different SACs.Furthermore,we briefly introduced the catalytic mechanism of SACs and discussed the strategies of synthesizing SACs,including the spatial confinement strategy and the coordination design strategy.Finally,the challenges and prospects in this field are proposed.We believe that this review would help to design and fabricate high-performance Li-S batteries via introducing SACs and boost their practical application.

Hierarchically porous materials： Synthesis strategies and emerging applications

Great interests have arisen over the last decade in the development of hierarchically porous materials. The hierarchical structure enables materials to have maximum structural functions owing to enhanced accessibility and mass transport properties, leading to improved perfor- mances in various applications. Hierarchical porous materials are in high demand for applications in catalysis, adsorption, separation, energy and biochemistry. In the present review, recent advances in synthesis routes to hierarchically porous materials are reviewed together with their catalytic contributions.

Challenging the limitation:Synthesis and application of complexes with the highest carbon coordination number in plane

Subject Code:B02With the support by the National Natural Science Foundation of China and the National Basic Research Program of China,the research team led by Prof.Xia Haiping(夏海平)of Xiamen University described the first example of CCCCC pentadentate chelate with all binding atoms being carbon atoms.This result represents a new record of planar carbon coordination number for a transition metal,which was

Application of carbene reactive intermediates in organic synthesis——Ⅲ.Reaction of difluorocarbene with trimethylsilyl enol ethers

The addition of difluorocarbene generated from phenyl(trifluoromethyl)mercury and anhydrous sodium iodide,with trimethylsilyl enol ethers derived from cyclohexanone,cycloheptanone, 3-pentanone and acetophenone was described.The corresponding 2,2-difluoro-1-trimethylsilyloxy- cyclopropanes were obtained in good yields.The thermal stability of these cyclopropyl derivatives was affected by the molecular strain and the nature of their substituents.Thus,1-trimethylsilyloxy- cyclopentene reacted with difluorocarbene to give only 2-fluoro-2-cyclohexen-1-one instead of the expected 1-trimethylsilyloxy-6,6-difluorobicyclo[3.1.0]hexane,and a mechanism for its formation was proposed.

Recent progress in synthesis of two-dimensional hexagonal boron nitride

Two-dimensional（2D） materials have recently received a great deal of attention due to their unique structures and fascinating properties,as well as their potential applications.2D hexagonal boron nitride（2D hBN）,an insulator with excellent thermal stability,chemical inertness,and unique electronic and optical properties,and a band gap of 5.97 e V,is considered to be an ideal candidate for integration with other 2D materials.Nevertheless,the controllable growth of high-quality 2D h-BN is still a great challenge.A comprehensive overview of the progress that has been made in the synthesis of 2D h-BN is presented,highlighting the advantages and disadvantages of various synthesis approaches.In addition,the electronic,optical,thermal,and mechanical properties,heterostructures,and related applications of 2D h-BN are discussed.