Trifunctional robust electrocatalysts based on 3D Fe/N-doped carbon nanocubes encapsulating Co4N nanoparticles for efficient battery-powered water electrolyzers

Herein,we have designed a highly active and robust trifunctional electrocatalyst derived from Prussian blue analogs,where Co_(4)N nanoparticles are encapsulated by Fe embedded in N-doped carbon nanocubes to synthesize hierarchically structured Co_(4)N@Fe/N-C for rechargeable zinc-air batteries and overall water-splitting electrolyzers.As confirmed by theoretical and experimental results,the high intrinsic oxygen reduction reaction,oxygen evolution reaction,and hydrogen evolution reaction activities of Co_(4)N@Fe/N-C were attributed to the formation of the heterointerface and the modulated local electronic structure.Moreover,Co_(4)N@Fe/N-C induced improvement in these trifunctional electrocatalytic activities owing to the hierarchical hollow nanocube structure,uniform distribution of Co_(4)N,and conductive encapsulation by Fe/N-C.Thus,the rechargeable zinc-air battery with Co_(4)N@Fe/N-C delivers a high specific capacity of 789.9 mAh g-1 and stable voltage profiles over 500 cycles.Furthermore,the overall water electrolyzer with Co_(4)N@Fe/N-C achieved better durability and rate performance than that with the Pt/C and IrO2 catalysts,delivering a high Faradaic efficiency of 96.4%.Along with the great potential of the integrated water electrolyzer powered by a zinc-air battery for practical applications,therefore,the mechanistic understanding and active site identification provide valuable insights into the rational design of advanced multifunctional electrocatalysts for energy storage and conversion.

Hetero-interfacial nickel nitride/vanadium oxynitride porous nanosheets as trifunctional electrodes for HER,OER and sodium ion batteries

The development of single electrode with multifunctional purposes for electrochemical devices remains a symbolic challenge in recent technology.This work explores interfacially-rich transition metal nitride hybrid that consist of nickel nitride and vanadium oxynitride(VO_(0.26)N_(0.52))on robust carbon fiber(denoted CF/Ni_(3)N/VON)as trifunctional electrode for hydrogen evolution reaction(HER),oxygen evolution reaction(OER),and sodium ion batteries(SIBs).The as-prepared CF/Ni_(3)N/VON exhibits low HER overpotential of 48 m V@10 m A cm^(-2),OER overpotential of 287 m V@10 m A cm^(-2),and sodium-ion anode storage reversible capacity of 555 m A h g^(-1)@0.2 C.Theoretical analyses reveal that the Ni_(3)N effectively facilitates hydrogen desorption for HER,increases the electrical conductivity for OER,and promotes the Na-ion storage intercalation process,while the VON substantially elevates the water dissociation kinetics for HER,accelerates the adsorption of OH*intermediate for OER and enhances the Na-ion surface adsorption storage process.Owing to the excellent HER and OER performances of the CF/Ni_(3)N/VON electrode,an overall water splitting device denoted as CF/Ni_(3)N/VON//CF/Ni_(3)N/VON was not only assembled showing an operating voltage of 1.63 V at current density of 10 m A cm^(-2)but was also successfully self-powered by the assembled CF/Ni_(3)N/VON//CF/Na_(3)V_(2)(PO_(4))_(3) flexible sodium ion battery.This work will contribute to the development of efficient and cost-effective flexible integrated electrochemical energy devices.

Self-supported metal(Fe, Co, Ni)-embedded nitrogen-doping carbon nanorod framework as trifunctional electrode for flexible Zn-air batteries and switchable water electrolysis

To meet the practical demand of wearable/portable electronics, developing high-efficiency and durable multifunctional catalyst and in-situ assembling catalysts into electrodes with flexible features are urgently needed but challenging. Herein, we report a simple route to fabricate bendable multifunctional electrodes by in-situ carbonization of metal ion absorbed polyaniline precursor. Alloy nanoparticles encapsulated in graphite layer are uniformly distributed in the N-doping carbon nanorod skeleton. Profiting from the favorable free-standing structure and the cooperative effect of metallic nanoparticles, graphitic layer and N doped-carbon architecture, the trifunctional electrodes exhibit prominent activities and stability toward HER, OER and ORR. Notably, due to the protection of carbon layer, the electrocatalysts show the reversible catalytic HER/OER properties. The overall water splitting device can continuously work for 12 h under frequent exchanges of cathode and anode. Importantly, the bendable metal air batteries fabricated by self-supported electrode not only displays the outstanding battery performance,achieving a decent peak power density(125 mW cm^(-2)) and exhibiting favorable charge-discharge durability of 22 h, but also holds superb flexible stability. Specially, a lightweight self-driven water splitting unit is demonstrated with stable hydrogen production.

MOF-derived Co-MOF,O-doped carbon as trifunctional electrocatalysts to enable highly efficient Zn-air batteries and water-splitting

Development of high-efficiency non-noble electrocatalysts for oxygen reduction reaction(ORR),oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)is urgently needed for high-performance Zn-air batteries and overall water splitting.Here,a facile strategy to synthesize novel Co-MOF,O-doped carbon(Co-MOF-T)based on Zn,Co-doped glucosamine and ZIF-8 by pyrolysis at temperature T was demonstrated.The prepared Co-MOF-800 showed a superior oxygen reduction reaction(ORR)activity comparable to that of commercial Pt/C catalyst.In addition,this catalyst shows great potential in the overall water splitting due to the excellent oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)activities.Based on the trifunctional activity,the primary Zn-air batteries using a Co-MOF-800 air electrode achieved a high open-circuit voltage of 1.38 V,a specific capacity of 671.6 mAh g^(-1) Zn,and a prominent peak power density of 144 mW cm^(-2).Also,the rechargeable Zn-air batteries based on CoMOF-800 air electrode could be smoothly run for 510 cycles with a low voltage gap of 0.58 V.Finally,the trifunctional Co-MOF-800 catalyst was applied to boost the electrochemical water splitting,demonstrating its promising potential as a green energy material for practical applications.

PA6 Obtained by Polymerization with Trifunctional Regulators and Its DSC Results

Hydrolytic polymerization of 8 - caprolactam is carried out by the use of trimesinic acid as molecular weight controlling agent, and polyamide 6 with three branched chains is obtained. The initial concentrations of regulators almost have no effect on the conversion of caprolactam , while relative viscosity of the polymer is affected by the concentrations. DSC investigation shows that DSC curve changes from single peak for regular polyamide 6 to one peak with one shoulder or one small peak for polyamide 6 with three branched chains and the melting point decreases with the increase of the amount of trimesinic acid. In addition, the concentration of trimesinic acid being the same, DSC curves change from almost sharp single peak to double peak with increasing reaction time.

Bimolecular reduction of carbon dioxide: double synthons for alkynes trifunctionalization

Carbon dioxide reduction, as a sustainable and versatile strategy for the access of chemical fuels, has attracted increasing attention and enormous efforts have been devoted to it in recent years. However, employing carbon dioxide as double synthons via bimolecular reduction remains challenging. Here, by leveraging the bimolecular reduction of carbon dioxide to carbonyl and methyl respectively, we describe a Pd-catalyzed trifunctionalization of alkynes with aryl iodide for the first time and showcase its advantages on the formation of various β-diketones and their application in the constructing of heterocyclic compounds with important biological activity, including pyrimidine, oxazole, pyrazole.

Spin-multiplexed full-space trifunctional terahertz metasurface[Invited]

The widespread use of multifunctional metasurfaces has started to revolutionize conventional electromagnetic devices due to their unprecedented capabilities and exceedingly low losses.Specifically,geometric metasurfaces that utilize spatially varied single-celled elements to impart arbitrary phase modulation under circularly polarized(CP)waves have attracted more attention.However,the geometric phase has intrinsically opposite signs for two spins,resulting in locked and mirrored functionalities for the right-handed and left-handed CP beams.Additionally,the demonstrated geometric metasurfaces so far have been limited to operating in either transmission or reflection modes at a single wavelength.Here,we propose a double-layered metasurface composed of complementary elliptical and reversal ring resonator structures to achieve simultaneous and independent control of the reflection and transmission of CP waves at two independent terahertz frequencies,which integrates three functions of reflected beam deflection,reflected Bessel beam generation,and transmitted beam focusing on the whole space.The high efficiency and simple design of our metasurface will open new avenues for integrated terahertz metadevices with advanced functionalities.

Engineering of Co_(3O)_(4)@Ni_(2)P heterostructure as trifunctional electrocatalysts for rechargeable zinc-air battery and self-powered overall water splitting

Rational design of highly efficient,robust and nonprecious electrocatalysts for the oxygen reduction reaction(ORR),oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)is highly demanded and challenging.Here,heterostructural Co_(3O)_(4)@Ni_(2)P arrays with numerous reaction sites,unique interfacial electronic structure and fast charge transfer kinetics are developed as electrocatalysts for rechargeable Zn-air batteries and overall water splitting.Both density functional theory calculation and X-ray absorption fine structure analysis manifest that the synergistic structural and abundant electronic modulations interfaces are formed,thus simultaneously promoting the electrocatalytic kinetics,activities and stabilities.Specifically,it can achieve an ultralow overpotential of 270 m V and 28 m V at 10 m A cm^(-2) for OER and HER,respectively.The water electrolyzer delivers a current density of 10 m A cm^(-2) at 1.563 V;furthermore,rechargeable Zn-air batteries triggered by this heterostructure can achieve excellent cyclic stability of 177 h(2 h per cycle)at 10 m A cm^(-2);both devices are superior to the Pt/C+Ir/C.This work not only designs an efficient trifunctional electrocatalyst but also paves an avenue to understand the heterostructure engineering for catalysts development and disclose the underlying relationship of interfacial electronic structures and catalytic properties.

Trifunctionalization of Aryl Iodides with Two Distinct Nitrogen and Carbon Electrophiles by Palladium/Norbornene Catalysis

Main observation and conclusion Herein,we report a highly chemo-and regioselective vicinal trifunctionalization of aryl iodides by palladium/norbornene(Pd/NBE)catalysis.The key feature of this new method is the introduction of two distinct nitrogen and carbon electrophiles,with a large gap in reactivity,for ortho-unsubstituted aryl iodides via an intermolecular and intramolecular C―H functionalization,respectively.Eight types of ipso terminations can be coupled with both ortho-amination and ortho-alkylation,affording a variety of polysubstituted benzoheterocyclic scaffolds.Silicon-tethered substrates can lead to polyfucntional arenes via a single-step operation.Noteworthy,these products exhibit full-color-tunable strong fluorescence emissions with large Stokes shifts,and product 7r can serve as a fluorescent probe to specifically target lysosome in living cells.

Copper-Catalyzed 1,2,5-Trifunctionalization of Terminal Alkynes Using SR as a Transient Directing Group for Radical Translocation

The first Cu-catalyzed 1,2,5-trifunctionalization of abundant terminal alkynes is realized by merging hydrogen atom transfer and traceless directing strategy with SR as a transient group,delivering highly functionalized aldehydes in moderate to excellent yields with broad substrate scope.The synthetic utility of this method was demonstrated by the gram-scale reaction and downstream transformations of the resultant products.Given the high efficient installation of three different functional groups in a single reaction,it can serve as a very attractive method for rapidly assembling complex molecules from readily available starting materials.

Cu/Pd-catalyzed borocarbonylative trifunctionalization of alkynes and allenes:synthesis ofβ-geminal-diboryl ketones

Functionalized bisboryl compounds have recently emerged as a new class of synthetically useful building blocks in organic synthesis.Herein,we report an efficient strategy to synthesizeβ-geminal-diboryl ketones enabled by a Cu/Pd-catalyzed borocarbonylative trifunctionalization of readily available alkynes and allenes.This reaction promises to be a useful method for the synthesis of functionalizedβ-geminal-diboryl ketones with broad functional group tolerance.Mechanistic studies suggest that the reaction proceeds through borocarbonylation/hydroboration cascade of both alkynes and allenes.

Aluminum and phosphorus codoped “superaerophobic” Co3O4 microspheres for highly efficient electrochemical water splitting and Zn-air batteries

Multifunctional non-precious catalysts for hydrogen/oxygen evolution reaction(HER/OER) and oxygen reduction reaction(ORR) constitute the bottleneck in the applications in electrochemical overall water splitting(OWS) and Zn-air batteries. Herein, a trifunctional electrocatalyst of urchin-like Al,P-codoped Co3O4 microspheres supported on Ni foam(denoted as AP-CONPs/NF) was fabricated via a hydrothermal process and subsequent low-temperature annealing and phosphorization, exhibiting enhanced OER, HER and ORR activities compared with single-doped and undoped samples. Their surface self-organized microstructure and excellent "superaerophobic" feature make a high bubble repellency, which boost diffusion of reactants and electrolyte-electrode intimate contact. The codoping of Al and P elements into Co3O4 betters right the balance among surface chemical state, the increased oxygen vacancies and the promoted charge transfer. Encouraged by these synergistic advantages, the AP-CONPs/NF was further employed as excellent bifunctional electrodes for the OWS(low cell voltage of 1.57 V at 10 mA cm-2) and as air cathode for rechargeable Zn-air batteries(high power density of 89.1 mW cm-2), which demonstrates a great feasibility for practical applications.

Photovoltaic-powered supercapacitors for driving overall water splitting:A dual-modulated 3D architecture

Due to the growing demand for clean and renewable hydrogen fuel,there has been a surge of interest in electrocatalytic water-splitting devices driven by renewable energy sources.However,the feasibility of self-driven water splitting is limited by inefficient connections between functional modules,lack of highly active and stable electrocatalysts,and intermittent and unpredictable renewable energy supply.Herein,we construct a dualmodulated three-dimensional(3D)NiCo_(2)O_(4)@NiCo_(2)S_(4)(denoted as NCONCS)heterostructure deposited on nickel foam as a multifunctional electrode for electrocatalytic water splitting driven by photovoltaic-powered supercapacitors.Due to a stable 3D architecture configuration,abundant active sites,efficient charge transfer,and tuned interface properties,the NCONCS delivers a high specific capacity and rate performance for supercapacitors.A twoelectrode electrolyzer assembled with the NCONCS as both the anode and the cathode only requires a low cell voltage of 1.47 V to achieve a current density of 10 mA cm^(−2) in alkaline electrolyte,which outperforms the state-of-the-art bifunctional electrocatalysts.Theoretical calculations suggest that the generated heterointerfaces in NCONCS improve the surface binding capability of reaction intermediates while regulating the local electronic structures,which thus accelerates the reaction kinetics of water electrolysis.As a proof of concept,an integrated configuration comprising a two-electrode electrolyzer driven by two series-connected supercapacitors charged by a solar cell delivers a high product yield with superior durability.

芳炔前体参与的芳烃1,2,3-三官能化反应

芳炔是一类重要的高活性反应中间体,由于它们可在芳环的相邻两个位置上同时实现不同基团的官能化,自发现以来已被广泛应用于有机合成化学中。传统单芳炔反应受到只能邻位双官能化的限制,无法有效发挥其在制备多取代芳环结构中的作用,目前国内外有关利用芳炔参与的的串联反应在芳环上一次性引入三个及以上官能团的报道非常少。文章综述了芳炔前体参与的芳烃1,2,3-三官能化反应及其在天然产物和药物的快捷合成方面的应用。

部分磷化双金属中心集成制备高性能三功能催化剂用于制氢和柔性锌-空气电池

开发高效且性能稳定的氧析出(OER)、氧还原(ORR)和氢析出(HER)三功能催化剂是制备能源存储与转换设备的关键.本文使用一步磷化法,在氮磷共掺杂碳基上制备了Fe Co金属合金/磷化物催化剂(Fe Co-P/PNC).该催化剂显示了良好的ORR性能,展现了0.86 V (vs.RHE,相对于可逆氢电极)的半波电位;在OER和HER反应中,催化剂在10 m A cm^(-2)的电流密度下的过电位分别为350和158 m V.密度泛函理论计算表明,磷在Fe Co磷化物和碳基体中皆起主导作用,使得该催化剂同时具有良好的ORR、OER和HER功能.以Fe Co-P/PNC为空气阴极组装的水系电池和柔性锌-空气电池的峰值功率密度分别为195.1和90.8 m W cm^(-2),且两种电池均具有优异的充放电性能、长寿命和高柔性.此外,自供能的整体水分解系统表现出较低的(1.71 V)工作电压以驱动10 m A cm^(-2)的电流密度,进一步证实了该催化剂出色的多功能性.

A chiral salen-Co(Ⅱ)complex as soluble redox mediator for promoting the electrochemical performance of Li-O_(2) batteries

Low discharge capacity and poor cycle stability are the major obstacles hindering the operation of Li-O_(2)batteries with highenergy-density.These obstacles are mainly caused by the cathode passivation behaviours and the accumulation of by-products.Promoting the discharge process in solution and accelerating the decomposition of discharge products and by-products are able to alleviate above problems to some extent.Herein,chiral salen-Co(Ⅱ)complex,(1R,2R)-(-)-N,N-bis(3,5-di-t-butylsalicylidene)-1,2-cyclohexanediaminocobalt(Ⅱ)(Co(Ⅱ))as a multi-functional redox mediator was introduced into electrolyte to induce solution phase formation of Li_(2)O_(2)and catalyze the oxidation of Li_(2)O_(2)and main by-products Li_(2)CO3.Due to the Co(Ⅱ)has the solvation effect towards Li+,it can drive solution phase formation of Li_(2)O_(2),to prevent electrode from passivation and then increase the discharge capacity with a high Li_(2)O_(2)yield of 96.09%.Furthermore,the Co(Ⅱ)possesses suitable redox couple potentials,and it does so while simultaneously boosting the oxidization of Li_(2)O_(2)and the decomposition of Li_(2)CO3,reducing charge overpotential,and promoting cycle lifespan.Thereby,a cell with Co(Ⅱ)achieved a long cycling stability at low charge plateau(3.66 V)over 252 cycles with a specific capacity of 500 mAh·gcarbon^(−1).