Enhancing MXene-based supercapacitors:Role of synthesis and 3D architectures

MXene has been the limelight for studies on electrode active materials,aiming at developing supercapacitors with boosted energy density to meet the emerging influx of wearable and portable electronic devices.Despite its various desirable properties including intrinsic flexibility,high specific surface area,excellent metallic conductivity and unique abundance of surface functionalities,its full potential for electrochemical performance is hindered by the notorious restacking phenomenon of MXene nanosheets.Ascribed to its two-dimensional(2D)nature and surface functional groups,inevitable Van der Waals interactions drive the agglomeration of nanosheets,ultimately reducing the exposure of electrochemically active sites to the electrolyte,as well as severely lengthening electrolyte ion transport pathways.As a result,energy and power density deteriorate,limiting the application versatility of MXene-based supercapacitors.Constructing 3D architectures using 2D nanosheets presents as a straightforward yet ingenious approach to mitigate the fatal flaws of MXene.However,the sheer number of distinct methodologies reported,thus far,calls for a systematic review that unravels the rationale behind such 3D MXene structural designs.Herein,this review aims to serve this purpose while also scrutinizing the structure–property relationship to correlate such structural modifications to their ensuing electrochemical performance enhancements.Besides,the physicochemical properties of MXene play fundamental roles in determining the effective charge storage capabilities of 3D MXene-based electrodes.This largely depends on different MXene synthesis techniques and synthesis condition variations,hence,elucidated in this review as well.Lastly,the challenges and perspectives for achieving viable commercialization of MXene-based supercapacitor electrodes are highlighted.

Synthesis and Design of Distillation Columns for Wide-Boiling Binary Mixtures with Vapor Recompression Heat Pumps

The vapor recompression heat pump(VRHP) distillation technology offers significant improvements in energy efficiency for distillation systems with small temperature differences between the top and bottom of the column. However, the separation of wide-boiling binary mixtures leads to substantial temperature differences between the top and bottom of the column. This limits the applicability of conventional VRHP due to high capital costs and strict performance requirements of the compressor. To overcome these challenges and to accommodate compressor operating conditions, a novel synthesis and design method is introduced to integrate VRHPs with wide-boiling binary mixture distillation columns(WBMDCs). This method enables quick determination of an initial configuration for the integrated WBMDC-VRHP system and helps identify the optimum configuration with the minimum total annual cost. Two examples, namely the separation of benzene/toluene and isopropanol/chlorobenzene, are employed to derive optimum configurations of the WBMDC-VRHP and compare them with the WBMDC. A systematic comparison between the WBMDC-VRHP and WBMDC demonstrates the superior steady-state performance and economic efficiency of the WBMDC-VRHP.

Rationally designing electrolyte additives for highly improving cyclability of LiNi_(0.5)Mn_(1.5)O_(4)/Graphite cells

High voltage is necessary for high energy lithium-ion batteries but difficult to achieve because of the highly deteriorated cyclability of the batteries.A novel strategy is developed to extend cyclability of a high voltage lithium-ion battery,LiNi_(0.5)Mn_(1.5)O_(4)/Graphite(LNMO/Graphite)cell,which emphasizes a rational design of an electrolyte additive that can effectively construct protective interphases on anode and cathode and highly eliminate the effect of hydrogen fluoride(HF).5-Trifluoromethylpyridine-trime thyl lithium borate(LTFMP-TMB),is synthesized,featuring with multi-functionalities.Its anion TFMPTMB-tends to be enriched on cathode and can be preferentially oxidized yielding TMB and radical TFMP-.Both TMB and radical TFMP can combine HF and thus eliminate the detrimental effect of HF on cathode,while the TMB dragged on cathode thus takes a preferential oxidation and constructs a protective cathode interphase.On the other hand,LTFMP-TMB is preferentially reduced on anode and constructs a protective anode interphase.Consequently,a small amount of LTFMP-TMB(0.2%)in 1.0 M LiPF6in EC/DEC/EMC(3/2/5,wt%)results in a highly improved cyclability of LNMO/Graphite cell,with the capacity retention enhanced from 52%to 80%after 150 cycles at 0.5 C between 3.5 and 4.8 V.The as-developed strategy provides a model of designing electrolyte additives for improving cyclability of high voltage batteries.

Design and Synthesis of Transparent Poly(acrylonitrile-butadiene-styrene) and Relationship Between Its Phase Construction and Transparency

A series of transparent ABS（T-ABS） resins were prepared by emulsion in situ suspension polymerization. The influences of the particle size and the content of rubber particles on the transparency of T-ABS resins were studied by varying the size and content of rubber particles in a single model system（rubber particles with a uniform size）. The optical properties of T-ABS resins were investigated in a mixed system of SBR/PB particles and a hi-modal particle system（rubber particles with two different sizes, 70 and 400 nm in diameter） of SBR particles. It was found that when the size of the smaller particles （ 70 nm） in the mixed system of SBR/PB particles was in the range of 50-100 nm in diameter, the T-ABS resins showed a better transparency. These results provide a flexible and practical process for the preparation of T-ABS resins with good optical and mechanical properties.

De Novo Design and Synthesis of Four-Helix Bundle Peptides

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Generalized Odd-Even Mode Theory and Mode Synthesis Antenna Design Approach

In this article,studies on the multimode excitation problem of waveguides and antennas,the balance/unbalance mech-anism and the balanced feeding techniques in dipole antenna systems are first briefly historically reviewed.In this context,general-ized odd-even mode theory is advanced to quantitatively and approximately describe the mutual coupling effect between a feed line and an antenna.As is mathematically deduced and demonstrated,the modal parity mismatch between the feed line and the antenna should ultimately dominate the unbalance phenomenon in antenna systems.Thus,an elegant,closed-form formula is derived to ap-proximately calculate the“unbalance degree”of a straight dipole off-center fed by a symmetric twin-wire line.Design approaches for the simplest,linear,1-D multimode resonant antennas are introduced.Moreover,the“falling tone excitation”law gauged based on prototype dipoles is revealed and used to develop a mode synthesis design approach for microstrip patch antennas(MPAs)and 2-D sectorial electric dipole antennas.Design examples with distinctive radiation performance are presented and discussed.Finally,possible development trends of multimode resonant antennas are prospected.

Design and Analysis of Hybrid Systems for Scooters

Hybrid technology has been widely developed for various vehicles in recent years.However,due to the limitation of size and space,it is difficult to apply the technology in the small two-wheeled vehicles,especially scooters.For scooters,the hybrid system could be with small capacity,and must be simple and affordable.The Purpose of this study is to analyze and develop the conceptual designs of fuel-electric hybrid systems especially for scooters.Firstly,the graph called ＂function power graph（FPG）＂ is defined,which transforms traditional mechanical schematic diagrams into simplified graphs,and makes the characteristics of hybrid systems can be identified clearly.Based on the FPG,a systematic method for synthesizing all possible arrangements of hybrid systems,then,is developed,and the hybrid system arrangements with one internal combustion engine（ICE）,one electric machine（M/G）,and some mechanical clutch units are all enumerated.In order to evaluate the applicability of these design concepts for Scooters,twelve system functions and three system complexities are defined,and this evaluation process can be automated numerically by using a computer program,which is Matlab in this study.With the systematic design and analysis methods developed,the function capability and characteristics of current hybrid systems can be easily identified,and also,new and useful hybrid systems are found for future possible applications.

DESIGN OF RECONFIGURABLE MANUFACTURING SYSTEMS WITH STRONGLY COUPLED NATURE

Today＇s manufacturing cnvironmem forces manufacturing companies to make as many product variations as possible at affordable costs within a short time. Mass customisation is one of most important technologies for companies to achieve their objectives. Efforts to mass customisation should be made on two aspects： （1） To modularize products and make them as less differences as possible; （2） To design manufacturing resources and make them provide as many processes variations as possible. This paper reports our recent work on aspect （2）, i.e. how to design a reconfignrable manufacturing system （RMS） so that it can be competent to accomplish various processes optimally; Reconfignrable robot system （RRS） is taken as an example. RMS design involves architecture design and configuration design, and configuration design is further divided in design analysis and design synthesis. Axiomatic design theory （ADT） is applied to architecture design, the features and issues of RRS configuration design are discussed, automatic modelling method is developed for design analysis, and concurrent design methodology is presented for design synthesis.

Designed Syntheses and Crystal Structures of Two Cis-cyanide Bridged Trinuclear Complexes

Two cyanide bridged trinuclear compounds [Fe（bpy）2（CN）2]·[Cu（Cyclam）]2（ClO4）4·DMF 1 and [Fe（Phen）2（CN）2]·[Cu（Cyclam）]2（ClO4）4·2CH3CN·4H2O 2 （Bpy = 2,2＇- bipyridine, Phen = 1,10-phenanthroline, Cyclam = 1,4,8,11-tetraaza-cyclotetradecane, and DMF = N,N-dimethylformamide） have been synthesized by using mononuclear [Fe（Phen）2（CN）2]·2H2O and [Fe（bpy）2（CN）2]·3H2O as precursors. These two complexes crystallize in monoclinic space groups P21/c and C2/c, respectively. For 1, a = 25.164（2）, b = 12.0405（11）, c = 20.4433（15） A, β = 91.948（3）°, V = 6190.5（9） A^3, Z = 4, Mr = 1418.90, Dc = 1.522 g/cm^3, F（000） = 2936, μ = 1.161 mm^-1, the final R = 0.0722 and wR = 0.2011 for 10779 observed reflections （I 〉 2σ（I））. For 2, a = 43.5945（0）, b = 11.8447（0）, c = 29.5637（2）A, β = 120.430（11）o, V = 13162.76（9） A^3, Z = 8, Mr = 1518.48, Dc = 1.533 g/cm^3, F（000） = 6288, μ = 1.101 mm^-1, the final R = 0.0711 and wR = 0.1783 for 11262 observed reflections （I 〉 2σ（I））.

The design and synthesis of Prussian blue analogs as a sustainable cathode for sodium-ion batteries

Sodium-ion batteries(SIBs)present great appeal in various energy storage systems,especifically for stationary grid storage,on account of the abundance of sources and low cost.Unfortunately,the commercialization of SIBs is mainly limited by available electrode materials,especially for the cathodes.Prussian blue analogs(PBAs),emerge as a promising alternative for their structural feasibility in the application of SIBs.Decreasing the defects(vacancies and coordinated water)is an effective strategy to achieve superior electrochemical performance during the synthetic processes.Herein,we summarize crystal structures,synthetic methods,electrochemical mechanisms,and the influences of synthesis conditions of PBAs in detail.This comprehensive overview on the current research progresses of PBAs will give guides and directions to solve the existing problems for their application in SIBs.

Synthesis of covalent organic framework materials and their application in the field of sensing

Covalent organic frameworks(COFs)are an emerging type of porous crystalline polymers formed by combining strong covalent bonds with organic building blocks.Due to their large surface area,high intrinsic pore space,good crystallization properties,high stability,and designability of the resultant units,COFs are widely studied and used in the fields of gas adsorption,drug transport,energy storage,photoelectric catalysis,electrochemistry,and sensors.In recent years,the rapid development of the Internet of Things and people’s yearning for a better life have put forward higher and more requirements for sensors,which are the core components of the Internet of Things.Therefore,this paper reviews the recent progress of COFs in synthesis methods and sensing applications,especially in the last five years.This paper first introduces structure,properties,and synthesis methods of COFs and discusses advantages and disadvantages of different synthesis methods.Then,the research progress of COFs in different sensing fields,such as metal ion sensors,gas sensors,biomedical sensors,humidity sensors,and pH sensors,is introduced systematically.Conclusions and prospects are also presented in order to provide a reference for researchers concerned with COFs and sensors.

Ionothermal Synthesis and Photoactivity of Ti_(17) and Ti_(19)-Oxo Clusters Functionalized by Sulfate and 1,10-Phenanthroline Ligands

In this study,we successfully synthesized two titanium-oxo clusters,namely Ti_(19)(μ_(3)-O)_(19)(μ_(2)-O)_(10)(1,10-phn)_(2)(OiPr)_(18)](PTC-178)and(EMIm)_(3)[Ti_(17)(μ_(4)-O)_(4)(μ_(3)-O)_(16)(μ_(2)-O)_(4)(SO_(4))_(3)(μ_(2)-OiPr)_(4)(OiPr)_(13)](PTC-179).These clusters were synthesized using an ionothermal reaction and possess similar nuclearity(Ti19 vs.Ti17)moieties.Additionally,we observed that these complexes exhibit varying activities for photocatalytic degradation of Methylene Blue(MB)dye and distinct photocurrent responses for photoelectrochemical studies due to their different surface-decorated ligands.This study provides valuable insights into the design of Ti-oxo molecular clusters with similar nuclearity but different surface environments,allowing for the establishment of critical structure-property relationships.Furthermore,our research contributes to the exploration of sustainable synthetic methods for high nuclearity TOCs using ionic liquids.

Synthesis of Cu-Doped Layered Transition Metal Oxide Cathode Materials Directly from Metal-Organic Frameworks for Sodium-Ion Batteries

Mn-based layered transition metal oxides are promising cathode materials for sodium-ion batteries(SIBs)because of their high theoretical capacities,abundant raw materials,and environment-friendly advantages.However,they often show insufficient performance due to intrinsic issues including poor structural stability and dissolution of Mn^(3+).Atomic doping is an effective way to address these structural degradation issues.Herein,we reported a new synthesis strategy of a Cu-doped layered cathode by directly calcinating a pure metal-organic framework.Benefiting from the unique structure of MOF with atomic-level Cu doping,a homogeneous Cu-doped layered compound P2-Na_(0.674)Cu_(0.01)Mn_(0.99)O_(2) was obtained.The Cu substitution promotes the crystal structural stability and suppresses the dissolution of Mn,thus preventing the structure degradation of the layered cathode materials.A remarkably enhanced cyclability is realized for the Cu-doped cathode compared with that without Cu doping,with 83.8%capacity retention after 300 cycles at 100 mA·g^(-1).Our findings provide new insights into the design of atomic-level doping layered cathode materials constructed by MOFs for high-performance SIBs.

Design and synthesis of novel coumarin analogs and their nematicidal activity against five phytonematodes

The presence of hydroxyl groups at the C4 and C7 positions in coumarin backbone has been proposed as a potential modification site for providing excellent bioactivity according to previous studies. A series of novel coumarin derivatives were rationally designed and synthesized by use of a complex catalytic system for a targeted modification at the above sites. These derivatives were assayed for nematicidal activity. As predicted, the derivatization enhanced the activity of the coumarins against five nematodes.Compounds 7b, 9a, 10 c and 11 c showed significant strong nematicidal broad spectrum activity against all tested nematodes. Compound 10 c was the most effective with the lowest LC50 values against Meloidogyne incognita（5.1 mmol/L）, Ditylenchus destructor（3.7 mmol/L）, Bursaphelenchus mucronatus（6.4 mmol/L）, Bursaphelenchus B. xylophilus（2.5 mmol/L） and Aphelenchoides besseyi（3.1 mmol/L）,respectively. A brief investigation on the structure–activity relationships（SAR） revealed that the targeted modification by a C7 hydroxyl was optimum compared with that of a C4 hydroxyl and that the coupling chain length was crucial for the nematicidal activity.

Design of a novel side-mounted leg mechanism with high flexibility for a multi-mission quadruped earth rover BJTUBOT

Earth rover is a class of emerging wheeled-leg robots for nature exploration.At present,few methods for these robots’leg design utilize a side-mounted spatial parallel mechanism.Thus,this paper presents a complete design process of a novel 5-degree-of-freedom(5-DOF)hybrid leg mechanism for our quadruped earth rover BJTUBOT.First,a general approach is proposed for constructing the novel leg mechanism.Subsequently,by evaluating the basic locomotion task(LT)of the rover based on screw theory,we determine the desired motion characteristic of the sidemounted leg and carry out its two feasible configurations.With regard to the synthesis method of the parallel mechanism,a family of concise hybrid leg mechanisms using the 6-DOF limbs and an L1F1C limb(which can provide a constraint force and a couple)is designed.In verifying the motion characteristics of this kind of leg,we select a typical(3-UPRU&RRRR)&R mechanism and then analyze its kinematic model,singularities,velocity mapping,workspace,dexterity,statics,and kinetostatic performance.Furthermore,the virtual quadruped rover equipped with this innovative leg mechanism is built.Various basic and specific LTs of the rover are demonstrated by simulation,which indicates that the flexibility of the legs can help the rover achieve multitasking.

Synthesis of 3,5-Dichloro-4-（1,1,2,2-tetrafluoroethoxy）phenyl Containing 1,2,3-Thiadiazole Derivatives via Ugi Reaction and Their Biological Activities

A series of novel 3,5-dichloro-4-（1,1,2,2-tetrafluoroethoxy）phenyl containing 4-methyl-l,2,3-thiadiazole derivatives were designed and synthesized via Ugi reaction. Their structures were confirmed by IR, 1H NMR, 13C NMR and high-resolution mass spectroscopy. The preliminary bioassay results indicated that some title compounds had good fungicide activity at 50 ug/mL; most of the compounds presented a certain degree of direct inhibition activity, good inactivation and curative activity against tobacco mosaic virus at 500 ug/mL and 100 ug/mL; some compounds showed good larvicidal activity against Plutella xylostella L. at 200 ug/mL and excellent larvicidal activities against Culex pipiens pallens at 2 ug/mL.

Sub-nm ruthenium cluster catalyst for decomposition as an efficient and robust and synthesis of ammonia： Break the ＂size shackles＂

Downsizing to sub-nm is a general strategy to reduce the cost of catalysts. However, theoretical Wulff-constructed model suggests that sub-nm clusters show little activity for various reactions such as ammonia decomposition and ammonia synthesis because of the lack of active sites. As clusters may deviate from the ideal model construction under reaction conditions, a host-guest strategy to synthesize thermally stable 1.0 run monodispersed Ru dusters by the pyrolysis of MIL-101 hosts is reported here to verify the hypothesis. For ammonia decomposition, the activity of the Ru clusters is 25 times higher than that of commercial Ru/active carbon （AC） at full-conversion temperature, while for ammonia synthesis, the activity of the Ru dusters is 500 times as high as that of promoted Ru NPs counterpart. The catalyst also maintains its activities for 40 h without any increase in the size. This model can be used to develop a host-guest strategy for designing thermally stable sub-nm clusters to atomic-efficiently catalyze reactions.

Rapid and Scalable Synthesis of Prussian Blue Analogue Nanocubes for Electrocatalytic Water Oxidation

Design and fabrication of earth-abundant electrocatalysts for oxygen evolution reaction(OER)is essential in improving the overall ef-ficiency of water electrolysis.In this work,we proposed a rapid and scalable synthesis route for fabricating Prussian blue analogue(PBA)nano cubes with tun able compositi ons and uniform particle size.With the structural ben efits of abu ndant surface sites,facile charge transfer behavior and favorable Co^(2+)-to-Co^(3+)pre-oxidation reaction,fast generation and accumulation of the catalytically active Co3+sites can be achieved for the CoCo PBA nano cubes,leadi ng to remarkable OER activity with simulta neously achieved low overpotential,large anodic current density,small Tafel slope as well as outstanding intrinsic activity.Of note,by performing Iong-term OER operati on,the CoCo PBA nano cubes exhibit a remarkable 5.5-folds performs nee enhan ceme nt,and obvious surface rec on struc-tion and the accumulation of high-valence Co species can be identified,proving the crucial role of pre-oxidation process in boosting the OER catalysis.This work proposed a un iversal approach for the rapid,scalable and con trollable fabricati on of the PBA-based materials,and the elucidation of the pre-oxidation process in facilitating the OER catalysis may provide useful guidanee for designing and optimizing advanced catalysts for energy-related electro-oxidation reactions in the future.

Synthesis and Insecticidal Evaluation of Novel Anthranilic Diamides Derivatives Containing 4-Chlorine Substituted N-Pyridylpyrazole

To search for potent insecticides targeting at ryanodine receptors(RyRs),a series of novel anthranilic diamides analogs containing 4-chlorine N-pyridylpyrazole were designed and synthesized.Their insecticidal activities were evaluated and the preliminary struc ture-activity relationships(SARs)were discussed.The insecticidal results showed that some of the compounds(8a-8h,8m,8n)exhibited good larvicidal activities against oriental armyworm at 2.5 mg·L^(-1),and compound 8m possessed 60%insecticidal activityat 0.5 mg·L^(-1).For diamondback moth,8m exhibited better activity than Chlorantraniliprole at a hundred fold preference.

Defect Luminescence Based Persistent Phosphors—From Controlled Synthesis to Bioapplications

Persistent luminescence is an optical phenomenon where solid phosphors can store photoenergy in defects and release the energy by luminescence after stopping excitation.Due to the intriguing optical characteristics,the defect luminescence based persistent phosphors have attracted enormous attention in recent decades,especially in biomedical fields such as biosensing and bioimagin8.Persistent luminescence nanoparticles(PLNPs)can effectively avoid the autofluorescence interference from complex samples or tissues,leading to significantly improved sensitivity in biological analysis.In this review,we summarized the methods to control the optical performance of PLNPs from the perspectives of controlled synthesis and defect regulation,and emphasized the close relationship between their optical performance and applications.We further provided a summary about a series of PLNPs nanoprobes designed by our group for biosensing and bioimaging.Our efforts,summarized in this review,will not only open a window for manipulating luminescence in PLNPs,but also further promote the application of PLNPs in biomedicine.