As a prevailing cathode material of lithium-ion batteries(LIBs),LiCoO_(2)(LCO)still encounters the tricky problems of structural collapse,whose morphological engineering and cation doping are crucial for surmounting t...As a prevailing cathode material of lithium-ion batteries(LIBs),LiCoO_(2)(LCO)still encounters the tricky problems of structural collapse,whose morphological engineering and cation doping are crucial for surmounting the mechanical strains and alleviating phase degradation upon cycling.Hereinafter,we propose a strategy using a zeolitic imidazolate framework(ZIF)as the self-sacrificing template to directionally prepare a series of LiNi_(0.1)Co_(0.9)O_(2)(LNCO)with tailorable electrochemical properties.The rational selection of sintering temperature imparts the superiority of the resultant products in lithium storage,during which the sample prepared at 700℃(LNCO-700)outperforms its counterparts in cyclability(156.8 mA h g^(-1)at 1 C for 200 cycles in half cells,1 C=275 mA g^(-1))and rate capability due to the expedited ion/electron transport and the strengthen mechanical robustness.The feasibility of proper Ni doping is also divulged by half/full cell tests and theoretical study,during which LNCO-700(167 mA h g^(-1)at 1 C for 100 cycles in full cells)surpasses LCO-700 in battery performance due to the mitigated phase deterioration,stabilized layered structu re,ameliorated electro nic co nductivity,a nd exalted lithium sto rage activity.This work systematically unveils tailorable electrochemical behaviors of LNCO to better direct their practical application.展开更多
LiFePO_(4),as a prevailing cathode material for lithium-ion batteries(LIBs),still encounters issues such as intrinsic poor electronic conductivity,inferior Li-ion diffusion kinetic,and two-phase transformation mechani...LiFePO_(4),as a prevailing cathode material for lithium-ion batteries(LIBs),still encounters issues such as intrinsic poor electronic conductivity,inferior Li-ion diffusion kinetic,and two-phase transformation mechanism involving substantial structural rearrangements,resulting in unsatisfactory rate performance.Carbon coating,cation doping,and morphological control have been widely employed to reconcile these issues.Inspired by these,we propose a synthetic route with metal–organic frameworks(MOFs)as self-sacrificial templates to simultaneously realize shape modulation,Mn doping,and N-doped carbon coating for enhanced electrochemical performances.The as-synthesized Li MnxFe1–xPO4/C(x=0,0.25,and0.5)deliver tunable electrochemical behaviors induced by the MOF templates,among which LiMn_(0.25)Fe_(0.75)PO_(4)/C outperforms its counterparts in cyclability(164.7 mA h g^(-1)after 200 cycles at 0.5 C)and rate capability(116.3 mA h g^(-1)at 10 C).Meanwhile,the ex-situ XRD reveals a dominant single-phase solid solution mechanism of LiMn_(0.25)Fe_(0.75)PO_(4)/C during delithiation,contrary to the pristine LiFePO_(4),without major structural reconstruction,which helps to explain the superior rate performance.Furthermore,the density functional theory(DFT)calculations verify the effects of Mn doping and embody the superiority of LiMn_(0.25)Fe_(0.75)PO_(4)/C as a LIB cathode,which well supports the experimental observations.This work provides insightful guidance for the design of tunable MOF-derived mixed transitionmetal systems for advanced LIBs.展开更多
Metal-organic frameworks(MOFs)can serve as prevailing anodes for lithium-ion batteries,due to their multiple redox-active sites and prominent structural compatibility.However,the poor electronic conductivity and infer...Metal-organic frameworks(MOFs)can serve as prevailing anodes for lithium-ion batteries,due to their multiple redox-active sites and prominent structural compatibility.However,the poor electronic conductivity and inferior cyclability hinder their further implementation.Herein,a synthetic methodology for trimetallic Fe-Co-Ni MOFs with nanoframe superstructures architecture(Fe-Co-Ni NFSs)via structural evolution is proposed for versatile anode materials for lithium storage.Ascribed to optimal compositional and structural optimization,the Fe-Co-Ni NFSs achieve exceptional electrochemical performance with superior specific capacity(1030 mAh g^(−1) at 0.1 A g^(−1)),outstanding rate capacity(414 mAh g^(−1) at 2 A g^(−1)),and prolonged cyclability(489 mAh g^(−1) upon 1000 cycles at 1 A g^(−1)).Both experimental and theoretical investigations reveal that the multi-component metal centers could boost electronic conductivity,confer multiple active sites,and energetically favor Li adsorption capability.Additionally,the nanoframe superstructures of Fe-Co-Ni NFSs could facilitate stress-buffering effect on volumetric expansion and prevent electrode pulverization,further improving the lithium storage capability.This work envisions a meticulous protocol for high-performance MOF anode materials for lithium-ion batteries.展开更多
Density functional theory at the BP86 level was used to investigate the influence of equatorial ligands on the Ni–Ni interactions and magnetic coupling properties of metal string complexes [Ni3(L)4(NCS)2] (L rep...Density functional theory at the BP86 level was used to investigate the influence of equatorial ligands on the Ni–Ni interactions and magnetic coupling properties of metal string complexes [Ni3(L)4(NCS)2] (L represents the rigid equatorial ligands; L = dzp- (1), mpmpa- (2), mppda- (3), mptpa- (4)). The following conclusions can be drawn. (1) With increasing the radius of the connecting atom in the cental ring in equatorial ligands, the two pyridine rings bend down, resulting in the decreasing distance between the two pyridine-nitrogen atoms and the Ni–Ni distance. Therefore, the strength order of the Ni–Ni interaction is 4 〉 2 〉 3 〉 1. The Ni–Ni interactions in 2 and 4 are stronger than those in Ni3(dpa)4(NCS)2 containing no-rigid equatorial ligands. (2) The calculated -Jab is 4 〉 2 〉 3 〉 1. There are two types of magnetic exchange pathways in these complexes: the σ-type pathway through the Ni36+ chains and the δ-type pathway through the equatorial ligands. The magnetic coupling through the metals is the dominant part. Hence, the magnetic coupling strength increases with increasing the Ni–Ni interaction. Modifying the radius of the connecting atom may be one of the means to fine tuning of magnetic coupling strength of this kind of metal string complexes.展开更多
The effects of axial ligand on the oxygen atom transfer(OAT)reaction from 5,10,15-tris(pentafluorophenyl)corrole((tpfc)MnVO)to dimethyl sulfide(DMS)have been investigated by density functional theory(DFT)calculations....The effects of axial ligand on the oxygen atom transfer(OAT)reaction from 5,10,15-tris(pentafluorophenyl)corrole((tpfc)MnVO)to dimethyl sulfide(DMS)have been investigated by density functional theory(DFT)calculations.Imidazole(Im),4-methylimidazole(4-MI)and pyridine(Py)were selected as the axial ligands.The results revealed that the axial ligand can form coordinate bond with(tpfc)MnVO in the transition state(TS)of the OAT reaction.The axial coordination favored charge transferring from(tpfc)MnVO to DMS,and weakened the Mn≡O bond in both singlet and triplet states.Furthermore,axial coordination can reduce the energy barrier of neutral(tpfc)MnVO from 23.62 kJ·mol^-1 to less than 3 kJ·mol^-1 in the triplet state,which is significantly lower than in the singlet state.This makes(tpfc)MnVO tend to direct the OAT reaction via triplet state pathway.On the other hand,the energy barriers of[(tpfc)MnVIO]+species from disproportionation pathway increased from 1.26 to 33.95 kJ·mol^-1 in a doublet state.This suggests axial ligands were conducive for direct(tpfc)MnVO OAT reaction pathway.展开更多
As a novel class of high-voltage cathode materials,spinel lithium transition metal oxides have been faced with demerits including pronounced structural instability caused by Jahn-Teller distortion(especially at the lo...As a novel class of high-voltage cathode materials,spinel lithium transition metal oxides have been faced with demerits including pronounced structural instability caused by Jahn-Teller distortion(especially at the lower voltage region)and severe capacity degradation despite their intriguing electrochemical properties.To extend their functionalities as broad-voltage cathodes,the sacrificial template method has been regarded as a promising way to realize structural and compositional control for desirable electrochemical behaviors.Herein,we report a synthetic protocol to directionally prepare Li Co Mn O_(4)(LCMO)using carboxyl-based metal-organic frameworks(MOFs)as self-sacrificing templates.Impressively,LCMO derived from Co Mn-BDC(H_(2)BDC=1,4-benzenedicarboxylate)displays superior electrochemical performances with a specific capacity of 151.6 m Ah g^(-1)at 1 C(150 m A g^(-1))after 120 cycles and excellent rate capacity of 91.9 m Ah g^(-1)at 10 C due to the morphology control,microstructural modulation,and atomic manipulation of the MOF precursor.Bestowed by the optimized atomic and electronic structure,abundant oxygen vacancies,and the nanostructure retained from MOF precursors,LCMO materials display extraordinary electrochemical properties,which have been extensively verified by both experimental and theoretical studies.This work not only provides guidelines for the directional design of spinel materials at molecular and atomic levels but also sheds light on the practical use of LIBs with broad range voltage.展开更多
We for the first time systematically studied the structures and electrochemical nitrogen reduction reaction properties of two-dimensional single transition-metal anchored square tetracyanoquinodimethane monolayers(lab...We for the first time systematically studied the structures and electrochemical nitrogen reduction reaction properties of two-dimensional single transition-metal anchored square tetracyanoquinodimethane monolayers(labeled as:TM-sTCNQ,TM=3d,4d,5d series transition metals)by employing density functional theory method.Through highthroughput screenings and full reaction path researches,two promising electrochemical nitrogen reduction reaction catalysts Nb-sTCNQ and MosTCNQ have been obtained.The nitrogen reduction reaction onset potential on Nb-sTCNQ is as low as−0.48 V.Furthermore,the Nb-sTCNQ catalyst can quickly desorb NH3 produced with a free energy of 0.65 eV,giving Nb-sTCNQ excellent catalytic cycle performance.The high catalytic activity of the two materials might be attributed to the effective charge transfer between the active center and adsorbed N_(2),which enables the active center to adsorb and activate inert N_(2) molecules well,and the reduction processes require small energy input(i.e.,the maximum free energy changes are small).This work provides insights for finding highly efficient,stable,and low-cost nitrogen reduction reaction electrocatalysts.We hope our results can promote further experimental and theoretical research of this field.展开更多
A concise and efficient method for the synthesis of novel 9,10-imethoxybenzo[6,7]oxepino[3,4-b]quinolin13(6H)-one and its derivatives 7a-p has been developed via the intramolecular Friedel-Crafts acylation reactions o...A concise and efficient method for the synthesis of novel 9,10-imethoxybenzo[6,7]oxepino[3,4-b]quinolin13(6H)-one and its derivatives 7a-p has been developed via the intramolecular Friedel-Crafts acylation reactions of 6,7-dimethoxy-2-(phenoxymethyl)quinoline-3-carboxylic acids 6a-p with polyphosphoric acid (PPA) as catalyst and solvent under mild conditions. The key intermediates 6a-p were prepared through the in situ formation of ethyl 6,7-dimethoxy-2-(phenoxymethyl)quinoline-3-carboxylates 5a-p followed by hydrolysis with aqueous ethanolic sodium hydroxide solution. The novel synthetic method has the advantages of good yields, easy work-up, and environmentally friendly character, which may provide a novel highly efficient process for making quinoline and related azaheterocycle libraries.展开更多
Palladium-catalyzed the Sonogashira coupling reaction of 3-halogen-2-aminopyridines 1 with terminal alkynes 2 afforded the corresponding 21 target products 3a-3u in the presence of palladium catalyst. The structure of...Palladium-catalyzed the Sonogashira coupling reaction of 3-halogen-2-aminopyridines 1 with terminal alkynes 2 afforded the corresponding 21 target products 3a-3u in the presence of palladium catalyst. The structure of target products 3a-3u was confirmed and characterized by 1H NMR, 13C NMR, and HRMS. The influences of different kinds of catalyst loading, bases, substrates and temperature were also investigated. Under the optimized conditions, including 2.5 mol% Pd?(CF3COO)2, 5 mol% PPh3 and 5 mol% CuI as additive, 1 mL Et3N, substrate 1 with terminal alkynes 2 for the cross-coupling reactions at 100°C for 3 h in DMF afforded the corresponding products of 2-amino-3-alkynylpyridines 3 in moderate to excellent yields (72%?-?96%). The present methodology has provided an effective synthetic method including operational convenience, high efficiency and wide-application.展开更多
Solving the problems of low electrical conductivity and poor cycling durability in transition metal oxidesbased anode materials for lithium-ion batteries(LIBs)and sodium-ion batteries(SIBs)has already turned into an u...Solving the problems of low electrical conductivity and poor cycling durability in transition metal oxidesbased anode materials for lithium-ion batteries(LIBs)and sodium-ion batteries(SIBs)has already turned into an urgent requirement.In this paper,we successfully synthesized Co_(2)VO_(4)/Co compounds with Co-VMOF(metal-organic framework)as a sacrificial template and investigated their electrochemical mechanism in order to improve the electrochemical properties of LIBs and SIBs.The optimized heaping configuration and the existence of metallic Co catalyzed the formation of radical ions,thereby facilitating higher conductivity,shortening Li+and Na+transport paths,and providing more active sites.Co_(2)VO_(4)/Co constructed with 2-methylimidazole as a ligand showed a discharge capacity of 1605.1 mA h g^(-1)after 300 cycles at 0.1 A g^(-1)in LIB and 677.2 mA h g^(-1)in SIB.Density functional theory(DFT)calculation emphasizes the crucial role of Co_(2)VO_(4)/Co in enhancing electrode conductivity,decreasing the migratory energy barrier,and thereby strengthening electrochemical properties.This heterostructure building technique may pave the way for the development of high-performance LIBs and SIBs.Furthermore,the problem of the low first-loop coulombic efficiency faced by transition metal oxides is improved.展开更多
The introduction of materials with dual-functionalities,i.e.,the catalytic(adsorption)features to inhibit shuttle effects at the cathode side,and the capability to facilitate homogenous Li-ion fluxes at the anode side...The introduction of materials with dual-functionalities,i.e.,the catalytic(adsorption)features to inhibit shuttle effects at the cathode side,and the capability to facilitate homogenous Li-ion fluxes at the anode side,is a promising strategy to realize high performance lithium-sulfur batteries(LSBs).Herein,a facile and rational organic“ligand-induced”(trimesic acid(TMA))transformation tactic is proposed,which achieves the regulation of electronic performance and d-band center of bimetallic oxides(NiFe_(2)O_(4))to promote bidirectional sulfur conversion kinetics and stabilize the Li plating/striping during the charge/discharge process.The battery assembled with NiFe_(2)O_(4)-TMA modified separator exhibits a remarkable initial specific capacity of 1476.6 mAh·g^(-1)at 0.1 C,outstanding rate properties(661.1 mAh·g^(-1)at 8.0 C),and excellent cycling ability.The“ligand-induced”transformation tactic proposed in this work will open a whole new possibility for tuning the electronic structure and d-band center to enhance the performance of LSBs.展开更多
Dear Editor,Life can utilize energy with high efficiency,especially with the help of aerobic respiration,where the tricarboxylic acid(TCA)cycle acts as an important metabolic engine for mitochondria to produce the cel...Dear Editor,Life can utilize energy with high efficiency,especially with the help of aerobic respiration,where the tricarboxylic acid(TCA)cycle acts as an important metabolic engine for mitochondria to produce the cell energy currency of adenosine triphosphate(ATP),and nicotinamide adenine dinucleotide(NAD)plays a particular role of energy management molecule in the TCA cycle[1].展开更多
The structures of complexes [MⅡ2Cl4L2] and [MⅢ2Cl7L]- (M = Mo, Re; L = Ph2Ppy, (Ph2P)2py) were calculated by using density functional theory (DFT) PBE0 method. Based on the optimized geometries, the natural bo...The structures of complexes [MⅡ2Cl4L2] and [MⅢ2Cl7L]- (M = Mo, Re; L = Ph2Ppy, (Ph2P)2py) were calculated by using density functional theory (DFT) PBE0 method. Based on the optimized geometries, the natural bond orbital (NBO) analyses were carried out to study the nature of Re-Re and Mo-Mo bonds. The conclusions are as follows: the M-M distances in two-Ph2Ppy or (Ph2P)2py complexes [MⅡ2Cl4L2] are shorter than those in mono-Ph2Ppy or (Ph2P)2py complexes [MⅢ2Cl7L]- due to the double bridged N-C-P interactions. For singlet of all complexes, there is ReⅢ-ReⅢ or MoⅡ-MoⅡ quadruply bond in complex [Re2Cl7L]- or [Mo2Cl4L2], while only ReⅡ-ReⅡ or MoⅢ-MoⅢ triply bond in complex [Re2Cl4L2] or [Mo2Cl7L]-. The most stable spin state of 2 and 6, triplet, only contains triple ReⅢ-ReⅢ bond. Because the LPCl → BD*Re-Re delocalizations weaken the Re-Re bond, the distance of ReⅢ-ReⅢ quadruple bonds in [Re2Cl7L]- is slightly longer than that of ReⅡ-ReⅡ triple bonds in [Re2Cl4L2]. Moreover, due to the delocalizations from the lone pair electrons of the remaining P’ atom to the M-M antibonding orbitals, the M-M distance in (Ph2P)2py complexes is slightly longer than that in Ph2Ppy complexes.展开更多
Despite the dazzling theoretical capacity,the devasting electrochemical activity of Li_(2)MnO_(3)(LMO)caused by the difficult oxidation of Mn4+impedes its practical application as the lithium-ion battery(LIB)cathode.T...Despite the dazzling theoretical capacity,the devasting electrochemical activity of Li_(2)MnO_(3)(LMO)caused by the difficult oxidation of Mn4+impedes its practical application as the lithium-ion battery(LIB)cathode.The efficacious activation of the Li_(2)MnO_(3) by importing electrochemically active Mn3+ions or morphological engineering is instrumental to its lithium storage activity and structural integrity upon cycling.Herein,we propose a conceptual strategy with metal-organic frameworks(MOFs)as self-sacrificial templates to prepare oxygen-deficient Li_(2)MnO_(3)(O_v-LMO)for exalted lithium storage performance.Attributed to optimized morphological features,LMO materials derived from Mn-BDC(H_(2)BDC=1,4-dicarboxybenzene)delivered superior cycling/rate performances compared with their counterparts derived from Mn-BTC(H_(3)BTC=1,3,5-benzenetricarboxylicacid)and Mn-PTC(H_(4)PTC=pyromellitic acid).Both experimental and theoretical studies elucidate the efficacious activation of primitive LMO materials toward advanced lithium storage by importing oxygen deficiencies.Impressively,O_v-LMO derived from Mn-BDC(O_v-BDC-LMO)delivered intriguing reversible capacities(179.2 mA h g^(-1)at 20 mA g^(-1)after 200 cycles and 100.1 mA h g^(-1)at 80 mA g^(-1)after 300 cycles),which can be attributed to the small particle size that shortens pathways for Li+/electron transport,the enhanced redox activity induced by abundant oxygen vacancies,and the optimized electronic configuration that contributes to the faster lithium diffusivity.This work provides insights into the rational design of LMO by morphological and atomic modulation to direct its activation and practical application as an advanced LIB cathode.展开更多
E-peroxone(EP)was one of the most attractive AOPs for removing refractory organic compounds from water,but the high energy consumption for in situ generating H_(2)O_(2) and its low reaction efficiency for activating O...E-peroxone(EP)was one of the most attractive AOPs for removing refractory organic compounds from water,but the high energy consumption for in situ generating H_(2)O_(2) and its low reaction efficiency for activating O_(3) under acidic conditions made the obstacles for its practical application.In this study,cerium oxide was loaded on the surface of graphite felt(GF)by the hydrothermal method to construct the efficient electrode(CeO_(x)/GF)for mineralizing carbamazepine(CBZ)via EP process.CeO_(x)/GF was an efficient cathode,which led to 69.4%TOC removal in CeO_(x)/GF-EP process with current intensity of 10 mA in 60 min.Moreover,CeO_(x)/GF had the flexible application in the pH range from 5.0 to 9.0,TOC removal had no obvious decline with decrease of pH.Comparative characterizations showed that CeO_(x)could enhance surface hydrophilicity and reduce the charge-transfer resistance of GF.About 5.4 mg/L H_(2)O_(2) generated in CeO_(x)/GF-EP process,which was 2.1 times as that in GF-EP process.The greater ozone utility was also found in CeO_(x)/GF-EP process.More O_(3) was activated into hydroxyl radicals,which accounted for the mineralization of CBZ.An interfacial electron transfer process was revealed,which involved the function of oxygen vacancies and Ce^(3+)/Ce^(4+)redox cycle.CeO_(x)/GF had the good recycling property in fifth times'use.展开更多
A wide variety of molecular probes have been developed for real-time analysis,but most of organic fluorophores possess small Stokes shifts and self-absorption or inner filter effect that could not be avoided.In this s...A wide variety of molecular probes have been developed for real-time analysis,but most of organic fluorophores possess small Stokes shifts and self-absorption or inner filter effect that could not be avoided.In this study,a new dicyanoisophorone-based derivative(E)-0-(4-(2-(3-(dicyanomethylene)-5,5-dimethylcyclohex-1-en-1-yl)vinyl)phenyl)diphenylphosphinothioate(λ_(ex)=405 nm,X_(em)=551 nm,denoted as ICM-S) with strong push-pull electron effect has been afforded and it exhibits red shift for absorption from 407 nm to 426 nm with distinct color change from pale yellow to deep yellow upon exposure to Hg~(2+).Moreover,an easily distinguishable fluorescence color change follows the route from green,yellow to red in the presence of Hg~(2+) over the range of 0-90 μmol/L(detection limit=137 nmol/L)can be observed by the naked eye under a UV lamp irradiation.Chlorodiphenylphosphine and sublimedsulfur are incorpo rated as re s ponsive sites and P-O bond has been cleaved upon the addition of mercu ry ions.During the recognition process,such dicyanoisophorone dye(ICM-S) has been evolved to 2-(3-(4-hydroxystyryl)-5,5-dimethylcyclohex-2-enylidene) malononitrile(ICM-OH).Clear evidences in the chemical processes can be identified via single crystal X-ray diffraction,spectroscopic analysis,photophysical studies and titration experiments.With the aim of exploring its potential in biological systems,its in vitro responses to Hg~(2+) have been evaluated in 293 T cells and the effectiveness in zebrafish model has also been verified.展开更多
Designing novel electrode materials with unique structures is of great significance for improving the performance of lithium ion batteries(LIBs).Herein,copper-doped Co_(1-x)Te@nitrogen-doped carbon hollow nanoboxes(Cu...Designing novel electrode materials with unique structures is of great significance for improving the performance of lithium ion batteries(LIBs).Herein,copper-doped Co_(1-x)Te@nitrogen-doped carbon hollow nanoboxes(Cu-Co_(1-x)Te@NC HNBs)have been fabricated by chemical etching of Cu Co-ZIF nanoboxes,followed by a successive high-temperature tellurization process.The as-synthesized Cu-Co_(1-x)Te@NC HNBs composite demonstrated faster ionic and electronic diffusion kinetics than the pristine Co Te@NC HNBs electrode.The existence of Co-vacancy promotes the reduction of Gibbs free energy change(ΔG_(H^(*)))and effectively improves the Li~+diffusion coefficient.XPS and theoretical calculations show that performance improvement is ascribed to the electronic interactions between Cu-Co_(1-x)Te and nitrogen-doped carbon(NC)that trigger the shift of the p-band towards facilitation of interfacial charge transfer,which in turn helps boost up the lithium storage property.Besides,the proposed Cu-doping-induced Co-vacancy strategy can also be extended to other conversion-type cobalt-based material(CoSe_(2))in addition to asobtained Cu-Co_(1-x)Se_(2)@NC HNBs anodes for long-life and high-capacity LIBs.More importantly,the fabricated LiCoO_(2)//Cu-Co_(1-x)Te@NC HNBs full cell exhibits a high energy density of 403 Wh kg^(-1)and a power density of 6000 W kg^(-1).We show that the energy/power density reported herein is higher than that of previously studied cobalt-based anodes,indicating the potential application of Cu-Co_(1-x)Te@NC HNBs as a superior electrode material for LIBs.展开更多
A transition metal-free and efficient synthesis of fused azapolycycles via a multicomponent reaction has been developed using mucohalic acid as a C_(3) synthon.The reaction promoted by the simple inorganic base K_(2)C...A transition metal-free and efficient synthesis of fused azapolycycles via a multicomponent reaction has been developed using mucohalic acid as a C_(3) synthon.The reaction promoted by the simple inorganic base K_(2)CO_(3) gives serial C_(1)-functionalized benzo[4,5]imidazo[1,2-a]pyridine products using symmetrical and unsymmetrical substrates with satisfactory yields.展开更多
To date,Co-based metal-organic frameworks(Co-MOFs)have drawn much attention owing to their advantages of easy preparation,high porosity and adjustable structure.Because of these enticing properties,numerous efforts ha...To date,Co-based metal-organic frameworks(Co-MOFs)have drawn much attention owing to their advantages of easy preparation,high porosity and adjustable structure.Because of these enticing properties,numerous efforts have been devoted to their applications in energy storage and conversion.However,poor conductivity has become one of the biggest obstacles for large-scale use of pristine Co-MOFs.Subsequently,many attempts have been carried out to develop various Co-MOF derived materials as electrodes for rechargeable batteries in order to address the above-mentioned shortcoming and to enhance the electrical conductivity with improved stability during cycling.Moreover,in addition to improvement of Li-ion batteries in practical utilization,seeking for other rechargeable batteries is another urgent task due to the high cost and limited sources of metallic Li.Herein,by following the recent research progress,this review provides an overview of applications of Co-MOF derived materials in various rechargeable batteries including lithium-ion batteries,sodium-ion batteries,lithium-sulfur batteries,zinc air batteries and other rechargeable batteries,where they have been utilized as cathodes,anodes,separators and electrocatalysts.Accordingly,we categorize and compare the morphology driven electrochemical performance of various Co-MOF derivatives including porous carbon,cobalt oxides,cobalt chalcogenides,cobalt phosphides and corresponding composites.Finally,current challenges for large-scale production and commercialization of Co-MOF derived materials as well as some reasonable solutions have been discussed at the end.展开更多
基金the financial support from the Special Funds for the Cultivation of Guangdong College Students’Scientific and Technological Innovation(“Climbing Program”Special Funds,pdjh2023b0145)Guangdong Provincial International Joint Research Center for Energy Storage Materials(2023A0505090009)。
文摘As a prevailing cathode material of lithium-ion batteries(LIBs),LiCoO_(2)(LCO)still encounters the tricky problems of structural collapse,whose morphological engineering and cation doping are crucial for surmounting the mechanical strains and alleviating phase degradation upon cycling.Hereinafter,we propose a strategy using a zeolitic imidazolate framework(ZIF)as the self-sacrificing template to directionally prepare a series of LiNi_(0.1)Co_(0.9)O_(2)(LNCO)with tailorable electrochemical properties.The rational selection of sintering temperature imparts the superiority of the resultant products in lithium storage,during which the sample prepared at 700℃(LNCO-700)outperforms its counterparts in cyclability(156.8 mA h g^(-1)at 1 C for 200 cycles in half cells,1 C=275 mA g^(-1))and rate capability due to the expedited ion/electron transport and the strengthen mechanical robustness.The feasibility of proper Ni doping is also divulged by half/full cell tests and theoretical study,during which LNCO-700(167 mA h g^(-1)at 1 C for 100 cycles in full cells)surpasses LCO-700 in battery performance due to the mitigated phase deterioration,stabilized layered structu re,ameliorated electro nic co nductivity,a nd exalted lithium sto rage activity.This work systematically unveils tailorable electrochemical behaviors of LNCO to better direct their practical application.
基金the financial support from the Research and Development Plan Project in Key Fields of Guangdong Province(2020B0101030005)Applied Special Project of Guangdong Provincial Science and Technology Plan(2017B090917002)+1 种基金Basic and Applied Basic Research Fund of Guangdong Province(2019B1515120027)Key R&D projects in Guangdong Province(2020B0101030005)。
文摘LiFePO_(4),as a prevailing cathode material for lithium-ion batteries(LIBs),still encounters issues such as intrinsic poor electronic conductivity,inferior Li-ion diffusion kinetic,and two-phase transformation mechanism involving substantial structural rearrangements,resulting in unsatisfactory rate performance.Carbon coating,cation doping,and morphological control have been widely employed to reconcile these issues.Inspired by these,we propose a synthetic route with metal–organic frameworks(MOFs)as self-sacrificial templates to simultaneously realize shape modulation,Mn doping,and N-doped carbon coating for enhanced electrochemical performances.The as-synthesized Li MnxFe1–xPO4/C(x=0,0.25,and0.5)deliver tunable electrochemical behaviors induced by the MOF templates,among which LiMn_(0.25)Fe_(0.75)PO_(4)/C outperforms its counterparts in cyclability(164.7 mA h g^(-1)after 200 cycles at 0.5 C)and rate capability(116.3 mA h g^(-1)at 10 C).Meanwhile,the ex-situ XRD reveals a dominant single-phase solid solution mechanism of LiMn_(0.25)Fe_(0.75)PO_(4)/C during delithiation,contrary to the pristine LiFePO_(4),without major structural reconstruction,which helps to explain the superior rate performance.Furthermore,the density functional theory(DFT)calculations verify the effects of Mn doping and embody the superiority of LiMn_(0.25)Fe_(0.75)PO_(4)/C as a LIB cathode,which well supports the experimental observations.This work provides insightful guidance for the design of tunable MOF-derived mixed transitionmetal systems for advanced LIBs.
基金We gratefully acknowledge the financial support from the Guangzhou Science and Technology Project (No.201904010213).
文摘Metal-organic frameworks(MOFs)can serve as prevailing anodes for lithium-ion batteries,due to their multiple redox-active sites and prominent structural compatibility.However,the poor electronic conductivity and inferior cyclability hinder their further implementation.Herein,a synthetic methodology for trimetallic Fe-Co-Ni MOFs with nanoframe superstructures architecture(Fe-Co-Ni NFSs)via structural evolution is proposed for versatile anode materials for lithium storage.Ascribed to optimal compositional and structural optimization,the Fe-Co-Ni NFSs achieve exceptional electrochemical performance with superior specific capacity(1030 mAh g^(−1) at 0.1 A g^(−1)),outstanding rate capacity(414 mAh g^(−1) at 2 A g^(−1)),and prolonged cyclability(489 mAh g^(−1) upon 1000 cycles at 1 A g^(−1)).Both experimental and theoretical investigations reveal that the multi-component metal centers could boost electronic conductivity,confer multiple active sites,and energetically favor Li adsorption capability.Additionally,the nanoframe superstructures of Fe-Co-Ni NFSs could facilitate stress-buffering effect on volumetric expansion and prevent electrode pulverization,further improving the lithium storage capability.This work envisions a meticulous protocol for high-performance MOF anode materials for lithium-ion batteries.
基金supported by the Natural Science Foundation of Guangdong Province(S2012010008763)Ministry of Education and Guangdong Province(2010B090400184)Science and Technology Program of Guangzhou City(2011J4300063)
文摘Density functional theory at the BP86 level was used to investigate the influence of equatorial ligands on the Ni–Ni interactions and magnetic coupling properties of metal string complexes [Ni3(L)4(NCS)2] (L represents the rigid equatorial ligands; L = dzp- (1), mpmpa- (2), mppda- (3), mptpa- (4)). The following conclusions can be drawn. (1) With increasing the radius of the connecting atom in the cental ring in equatorial ligands, the two pyridine rings bend down, resulting in the decreasing distance between the two pyridine-nitrogen atoms and the Ni–Ni distance. Therefore, the strength order of the Ni–Ni interaction is 4 〉 2 〉 3 〉 1. The Ni–Ni interactions in 2 and 4 are stronger than those in Ni3(dpa)4(NCS)2 containing no-rigid equatorial ligands. (2) The calculated -Jab is 4 〉 2 〉 3 〉 1. There are two types of magnetic exchange pathways in these complexes: the σ-type pathway through the Ni36+ chains and the δ-type pathway through the equatorial ligands. The magnetic coupling through the metals is the dominant part. Hence, the magnetic coupling strength increases with increasing the Ni–Ni interaction. Modifying the radius of the connecting atom may be one of the means to fine tuning of magnetic coupling strength of this kind of metal string complexes.
基金supported by the National Natural Science Foundation of China(21275057,21671068)Natural Science Foundation of Guangdong Province(S2012010008763,2017A050506048)
文摘The effects of axial ligand on the oxygen atom transfer(OAT)reaction from 5,10,15-tris(pentafluorophenyl)corrole((tpfc)MnVO)to dimethyl sulfide(DMS)have been investigated by density functional theory(DFT)calculations.Imidazole(Im),4-methylimidazole(4-MI)and pyridine(Py)were selected as the axial ligands.The results revealed that the axial ligand can form coordinate bond with(tpfc)MnVO in the transition state(TS)of the OAT reaction.The axial coordination favored charge transferring from(tpfc)MnVO to DMS,and weakened the Mn≡O bond in both singlet and triplet states.Furthermore,axial coordination can reduce the energy barrier of neutral(tpfc)MnVO from 23.62 kJ·mol^-1 to less than 3 kJ·mol^-1 in the triplet state,which is significantly lower than in the singlet state.This makes(tpfc)MnVO tend to direct the OAT reaction via triplet state pathway.On the other hand,the energy barriers of[(tpfc)MnVIO]+species from disproportionation pathway increased from 1.26 to 33.95 kJ·mol^-1 in a doublet state.This suggests axial ligands were conducive for direct(tpfc)MnVO OAT reaction pathway.
基金the financial support from the Special Funds for the Cultivation of Guangdong College Students’Scientific and Technological Innovation(“Climbing Program”Special Funds,pdjh2022b0135)the Open Fund of Energy and Materials Chemistry Joint Laboratory of SCNU and TINCI(SCNU-TINCI202207)。
文摘As a novel class of high-voltage cathode materials,spinel lithium transition metal oxides have been faced with demerits including pronounced structural instability caused by Jahn-Teller distortion(especially at the lower voltage region)and severe capacity degradation despite their intriguing electrochemical properties.To extend their functionalities as broad-voltage cathodes,the sacrificial template method has been regarded as a promising way to realize structural and compositional control for desirable electrochemical behaviors.Herein,we report a synthetic protocol to directionally prepare Li Co Mn O_(4)(LCMO)using carboxyl-based metal-organic frameworks(MOFs)as self-sacrificing templates.Impressively,LCMO derived from Co Mn-BDC(H_(2)BDC=1,4-benzenedicarboxylate)displays superior electrochemical performances with a specific capacity of 151.6 m Ah g^(-1)at 1 C(150 m A g^(-1))after 120 cycles and excellent rate capacity of 91.9 m Ah g^(-1)at 10 C due to the morphology control,microstructural modulation,and atomic manipulation of the MOF precursor.Bestowed by the optimized atomic and electronic structure,abundant oxygen vacancies,and the nanostructure retained from MOF precursors,LCMO materials display extraordinary electrochemical properties,which have been extensively verified by both experimental and theoretical studies.This work not only provides guidelines for the directional design of spinel materials at molecular and atomic levels but also sheds light on the practical use of LIBs with broad range voltage.
基金support from the National Natural Science Foundation of China(22073033,21873032,21673087,21903032)startup fund(2006013118 and 3004013105)from Huazhong University of Science and Technology+5 种基金the Fundamental Research Funds for the Central Universities(2019kfyRCPY116)the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(B21003)support from Guangdong Basic and Applied Basic Research Foundation(2021A1515010382)the computational resources from the computing cluster at the Key Laboratory of Theoretical Chemistry of Environment,Ministry of Education&School of Chemistry,South China Normal UniversityThe work was carried out at the LvLiang Cloud Computing Center of China,and the calculations were performed on TianHe-2The computing work in this paper is supported by the Public Service Platform of High Performance Computing by Network and Computing Center of HUST.
文摘We for the first time systematically studied the structures and electrochemical nitrogen reduction reaction properties of two-dimensional single transition-metal anchored square tetracyanoquinodimethane monolayers(labeled as:TM-sTCNQ,TM=3d,4d,5d series transition metals)by employing density functional theory method.Through highthroughput screenings and full reaction path researches,two promising electrochemical nitrogen reduction reaction catalysts Nb-sTCNQ and MosTCNQ have been obtained.The nitrogen reduction reaction onset potential on Nb-sTCNQ is as low as−0.48 V.Furthermore,the Nb-sTCNQ catalyst can quickly desorb NH3 produced with a free energy of 0.65 eV,giving Nb-sTCNQ excellent catalytic cycle performance.The high catalytic activity of the two materials might be attributed to the effective charge transfer between the active center and adsorbed N_(2),which enables the active center to adsorb and activate inert N_(2) molecules well,and the reduction processes require small energy input(i.e.,the maximum free energy changes are small).This work provides insights for finding highly efficient,stable,and low-cost nitrogen reduction reaction electrocatalysts.We hope our results can promote further experimental and theoretical research of this field.
文摘A concise and efficient method for the synthesis of novel 9,10-imethoxybenzo[6,7]oxepino[3,4-b]quinolin13(6H)-one and its derivatives 7a-p has been developed via the intramolecular Friedel-Crafts acylation reactions of 6,7-dimethoxy-2-(phenoxymethyl)quinoline-3-carboxylic acids 6a-p with polyphosphoric acid (PPA) as catalyst and solvent under mild conditions. The key intermediates 6a-p were prepared through the in situ formation of ethyl 6,7-dimethoxy-2-(phenoxymethyl)quinoline-3-carboxylates 5a-p followed by hydrolysis with aqueous ethanolic sodium hydroxide solution. The novel synthetic method has the advantages of good yields, easy work-up, and environmentally friendly character, which may provide a novel highly efficient process for making quinoline and related azaheterocycle libraries.
文摘Palladium-catalyzed the Sonogashira coupling reaction of 3-halogen-2-aminopyridines 1 with terminal alkynes 2 afforded the corresponding 21 target products 3a-3u in the presence of palladium catalyst. The structure of target products 3a-3u was confirmed and characterized by 1H NMR, 13C NMR, and HRMS. The influences of different kinds of catalyst loading, bases, substrates and temperature were also investigated. Under the optimized conditions, including 2.5 mol% Pd?(CF3COO)2, 5 mol% PPh3 and 5 mol% CuI as additive, 1 mL Et3N, substrate 1 with terminal alkynes 2 for the cross-coupling reactions at 100°C for 3 h in DMF afforded the corresponding products of 2-amino-3-alkynylpyridines 3 in moderate to excellent yields (72%?-?96%). The present methodology has provided an effective synthetic method including operational convenience, high efficiency and wide-application.
基金financially supported by the Open Fund of Energy and Materials Chemistry Joint Laboratory of SCNU and TINCI,China (SCNU-TINCI-202207)。
文摘Solving the problems of low electrical conductivity and poor cycling durability in transition metal oxidesbased anode materials for lithium-ion batteries(LIBs)and sodium-ion batteries(SIBs)has already turned into an urgent requirement.In this paper,we successfully synthesized Co_(2)VO_(4)/Co compounds with Co-VMOF(metal-organic framework)as a sacrificial template and investigated their electrochemical mechanism in order to improve the electrochemical properties of LIBs and SIBs.The optimized heaping configuration and the existence of metallic Co catalyzed the formation of radical ions,thereby facilitating higher conductivity,shortening Li+and Na+transport paths,and providing more active sites.Co_(2)VO_(4)/Co constructed with 2-methylimidazole as a ligand showed a discharge capacity of 1605.1 mA h g^(-1)after 300 cycles at 0.1 A g^(-1)in LIB and 677.2 mA h g^(-1)in SIB.Density functional theory(DFT)calculation emphasizes the crucial role of Co_(2)VO_(4)/Co in enhancing electrode conductivity,decreasing the migratory energy barrier,and thereby strengthening electrochemical properties.This heterostructure building technique may pave the way for the development of high-performance LIBs and SIBs.Furthermore,the problem of the low first-loop coulombic efficiency faced by transition metal oxides is improved.
基金This work was financially supported by the Natural Science Foundation of Guangdong Province(No.2019A1515011727)the Open Fund of the Guangdong Provincial Key Laboratory of Advance Energy Storage Materials.We also acknowledge the fund of Natural Science Foundation of Hubei Province(No.2021CFB011)the National Natural Science Foundation of China(Nos.52104309 and 52161033).
文摘The introduction of materials with dual-functionalities,i.e.,the catalytic(adsorption)features to inhibit shuttle effects at the cathode side,and the capability to facilitate homogenous Li-ion fluxes at the anode side,is a promising strategy to realize high performance lithium-sulfur batteries(LSBs).Herein,a facile and rational organic“ligand-induced”(trimesic acid(TMA))transformation tactic is proposed,which achieves the regulation of electronic performance and d-band center of bimetallic oxides(NiFe_(2)O_(4))to promote bidirectional sulfur conversion kinetics and stabilize the Li plating/striping during the charge/discharge process.The battery assembled with NiFe_(2)O_(4)-TMA modified separator exhibits a remarkable initial specific capacity of 1476.6 mAh·g^(-1)at 0.1 C,outstanding rate properties(661.1 mAh·g^(-1)at 8.0 C),and excellent cycling ability.The“ligand-induced”transformation tactic proposed in this work will open a whole new possibility for tuning the electronic structure and d-band center to enhance the performance of LSBs.
基金supported by the National Key R&D Program of China(2021YFA1200404 and 2018YFE0205501)the National Natural Science Foundation of China(T224100002).
文摘Dear Editor,Life can utilize energy with high efficiency,especially with the help of aerobic respiration,where the tricarboxylic acid(TCA)cycle acts as an important metabolic engine for mitochondria to produce the cell energy currency of adenosine triphosphate(ATP),and nicotinamide adenine dinucleotide(NAD)plays a particular role of energy management molecule in the TCA cycle[1].
基金the Natural Science Foundation of Guangdong Province (9151063101000037)Ministry of Education and Guangdong Province (2010B090400184)+2 种基金Program of Talent Introduction of Guangdong Province (C10133)Science and Technology Program of Guangzhou City (2011J4300063)Science and Technology Program of Guangdong Province (2010B060900007)
文摘The structures of complexes [MⅡ2Cl4L2] and [MⅢ2Cl7L]- (M = Mo, Re; L = Ph2Ppy, (Ph2P)2py) were calculated by using density functional theory (DFT) PBE0 method. Based on the optimized geometries, the natural bond orbital (NBO) analyses were carried out to study the nature of Re-Re and Mo-Mo bonds. The conclusions are as follows: the M-M distances in two-Ph2Ppy or (Ph2P)2py complexes [MⅡ2Cl4L2] are shorter than those in mono-Ph2Ppy or (Ph2P)2py complexes [MⅢ2Cl7L]- due to the double bridged N-C-P interactions. For singlet of all complexes, there is ReⅢ-ReⅢ or MoⅡ-MoⅡ quadruply bond in complex [Re2Cl7L]- or [Mo2Cl4L2], while only ReⅡ-ReⅡ or MoⅢ-MoⅢ triply bond in complex [Re2Cl4L2] or [Mo2Cl7L]-. The most stable spin state of 2 and 6, triplet, only contains triple ReⅢ-ReⅢ bond. Because the LPCl → BD*Re-Re delocalizations weaken the Re-Re bond, the distance of ReⅢ-ReⅢ quadruple bonds in [Re2Cl7L]- is slightly longer than that of ReⅡ-ReⅡ triple bonds in [Re2Cl4L2]. Moreover, due to the delocalizations from the lone pair electrons of the remaining P’ atom to the M-M antibonding orbitals, the M-M distance in (Ph2P)2py complexes is slightly longer than that in Ph2Ppy complexes.
基金the financial support from the Special Funds for the Cultivation of Guangdong College Students’Scientific and Technological Innovation(“Climbing Program”Special Funds,pdjh2023b0145)the Research and Development Plan Project in Key Fields of Guangdong Province(2020B0101030005)+1 种基金the Applied special project of Guangdong Provincial Science and Technology Plan(2017B090917002)the Basic and Applied Basic Research Fund of Guangdong Province(2019B1515120027)。
文摘Despite the dazzling theoretical capacity,the devasting electrochemical activity of Li_(2)MnO_(3)(LMO)caused by the difficult oxidation of Mn4+impedes its practical application as the lithium-ion battery(LIB)cathode.The efficacious activation of the Li_(2)MnO_(3) by importing electrochemically active Mn3+ions or morphological engineering is instrumental to its lithium storage activity and structural integrity upon cycling.Herein,we propose a conceptual strategy with metal-organic frameworks(MOFs)as self-sacrificial templates to prepare oxygen-deficient Li_(2)MnO_(3)(O_v-LMO)for exalted lithium storage performance.Attributed to optimized morphological features,LMO materials derived from Mn-BDC(H_(2)BDC=1,4-dicarboxybenzene)delivered superior cycling/rate performances compared with their counterparts derived from Mn-BTC(H_(3)BTC=1,3,5-benzenetricarboxylicacid)and Mn-PTC(H_(4)PTC=pyromellitic acid).Both experimental and theoretical studies elucidate the efficacious activation of primitive LMO materials toward advanced lithium storage by importing oxygen deficiencies.Impressively,O_v-LMO derived from Mn-BDC(O_v-BDC-LMO)delivered intriguing reversible capacities(179.2 mA h g^(-1)at 20 mA g^(-1)after 200 cycles and 100.1 mA h g^(-1)at 80 mA g^(-1)after 300 cycles),which can be attributed to the small particle size that shortens pathways for Li+/electron transport,the enhanced redox activity induced by abundant oxygen vacancies,and the optimized electronic configuration that contributes to the faster lithium diffusivity.This work provides insights into the rational design of LMO by morphological and atomic modulation to direct its activation and practical application as an advanced LIB cathode.
基金funded by the National Natural Science Foundation(No.51978288)Natural Science Foundation of Guangdong Province(No.2019A1515012202)Major Science and Technology Program for Water Pollution Control and Treatment in China(No.2017ZX07202-004).
文摘E-peroxone(EP)was one of the most attractive AOPs for removing refractory organic compounds from water,but the high energy consumption for in situ generating H_(2)O_(2) and its low reaction efficiency for activating O_(3) under acidic conditions made the obstacles for its practical application.In this study,cerium oxide was loaded on the surface of graphite felt(GF)by the hydrothermal method to construct the efficient electrode(CeO_(x)/GF)for mineralizing carbamazepine(CBZ)via EP process.CeO_(x)/GF was an efficient cathode,which led to 69.4%TOC removal in CeO_(x)/GF-EP process with current intensity of 10 mA in 60 min.Moreover,CeO_(x)/GF had the flexible application in the pH range from 5.0 to 9.0,TOC removal had no obvious decline with decrease of pH.Comparative characterizations showed that CeO_(x)could enhance surface hydrophilicity and reduce the charge-transfer resistance of GF.About 5.4 mg/L H_(2)O_(2) generated in CeO_(x)/GF-EP process,which was 2.1 times as that in GF-EP process.The greater ozone utility was also found in CeO_(x)/GF-EP process.More O_(3) was activated into hydroxyl radicals,which accounted for the mineralization of CBZ.An interfacial electron transfer process was revealed,which involved the function of oxygen vacancies and Ce^(3+)/Ce^(4+)redox cycle.CeO_(x)/GF had the good recycling property in fifth times'use.
基金Guangzhou Science and Technology Plan(No.202002030325)Science and Technology Plan of Guangdong Province(No.2020A0505100055)+3 种基金National Natural Science Foundation of China-Guangdong Joint Funding Support(No.U1801256)Science and Technology Program of Guangzhou(No.201905001)Guangdong Provincial Key Laboratory of Optical Information Materials and Technology(No.2017B030301007)Project of Central Plains Science and TechnologyInnovation Leading Talents of Henan Province(No.204200510001)。
文摘A wide variety of molecular probes have been developed for real-time analysis,but most of organic fluorophores possess small Stokes shifts and self-absorption or inner filter effect that could not be avoided.In this study,a new dicyanoisophorone-based derivative(E)-0-(4-(2-(3-(dicyanomethylene)-5,5-dimethylcyclohex-1-en-1-yl)vinyl)phenyl)diphenylphosphinothioate(λ_(ex)=405 nm,X_(em)=551 nm,denoted as ICM-S) with strong push-pull electron effect has been afforded and it exhibits red shift for absorption from 407 nm to 426 nm with distinct color change from pale yellow to deep yellow upon exposure to Hg~(2+).Moreover,an easily distinguishable fluorescence color change follows the route from green,yellow to red in the presence of Hg~(2+) over the range of 0-90 μmol/L(detection limit=137 nmol/L)can be observed by the naked eye under a UV lamp irradiation.Chlorodiphenylphosphine and sublimedsulfur are incorpo rated as re s ponsive sites and P-O bond has been cleaved upon the addition of mercu ry ions.During the recognition process,such dicyanoisophorone dye(ICM-S) has been evolved to 2-(3-(4-hydroxystyryl)-5,5-dimethylcyclohex-2-enylidene) malononitrile(ICM-OH).Clear evidences in the chemical processes can be identified via single crystal X-ray diffraction,spectroscopic analysis,photophysical studies and titration experiments.With the aim of exploring its potential in biological systems,its in vitro responses to Hg~(2+) have been evaluated in 293 T cells and the effectiveness in zebrafish model has also been verified.
基金the Natural Science Foundation of Anhui Province Higher Education Institutions(No.KJ2021A0501)the Foundation of Scientific Research Project of Anhui Polytechnic University(No.Xjky2020090)+4 种基金the Anhui Laboratory of Functional Coordinated Complexes for Materials Chemistry and Application(Nos.LFCCMCA-01 and LFCCMCA-06)the Scientific Research Launch Project of Anhui Polytechnic University(No.2020YQQ057)the Innovation and Entrepreneurship Training Program for College Students in Anhui Province(No.S202110363265)the National Key Research and Development Program of China(2019YFA0705702)the National Natural Science Foundation of China(21902188)。
文摘Designing novel electrode materials with unique structures is of great significance for improving the performance of lithium ion batteries(LIBs).Herein,copper-doped Co_(1-x)Te@nitrogen-doped carbon hollow nanoboxes(Cu-Co_(1-x)Te@NC HNBs)have been fabricated by chemical etching of Cu Co-ZIF nanoboxes,followed by a successive high-temperature tellurization process.The as-synthesized Cu-Co_(1-x)Te@NC HNBs composite demonstrated faster ionic and electronic diffusion kinetics than the pristine Co Te@NC HNBs electrode.The existence of Co-vacancy promotes the reduction of Gibbs free energy change(ΔG_(H^(*)))and effectively improves the Li~+diffusion coefficient.XPS and theoretical calculations show that performance improvement is ascribed to the electronic interactions between Cu-Co_(1-x)Te and nitrogen-doped carbon(NC)that trigger the shift of the p-band towards facilitation of interfacial charge transfer,which in turn helps boost up the lithium storage property.Besides,the proposed Cu-doping-induced Co-vacancy strategy can also be extended to other conversion-type cobalt-based material(CoSe_(2))in addition to asobtained Cu-Co_(1-x)Se_(2)@NC HNBs anodes for long-life and high-capacity LIBs.More importantly,the fabricated LiCoO_(2)//Cu-Co_(1-x)Te@NC HNBs full cell exhibits a high energy density of 403 Wh kg^(-1)and a power density of 6000 W kg^(-1).We show that the energy/power density reported herein is higher than that of previously studied cobalt-based anodes,indicating the potential application of Cu-Co_(1-x)Te@NC HNBs as a superior electrode material for LIBs.
基金Financial support from the Guangdong Basic and Applied Basic Research Foundation(no.2021A1515012342)the National Natural Science Foundation of China(no.81960883)+2 种基金the Scientific Research Fund of Jiangxi Provincial Education Department(no.GJJ201504)the Guangdong Provincial Science and Technology Project(no.2017A010103016)the Scientific Research Project of Gannan Medical University(no.YB201903)is greatly appreciated.
文摘A transition metal-free and efficient synthesis of fused azapolycycles via a multicomponent reaction has been developed using mucohalic acid as a C_(3) synthon.The reaction promoted by the simple inorganic base K_(2)CO_(3) gives serial C_(1)-functionalized benzo[4,5]imidazo[1,2-a]pyridine products using symmetrical and unsymmetrical substrates with satisfactory yields.
基金Project(21875076)supported by the National Natural Science Foundation of ChinaProjects(2018A050506077,2017A050506048)supported by the Scientific and Technological Plan of Guangdong Province,ChinaProject(201910574037)supported by the Undergraduates’ Innovating Experimentation Project of China
基金financially supported by the Guangzhou Science and Technology Project,China(No.201904010213)the Foundation of Anhui Province Key Laboratory of Functional Coordinated Complexes for Materials Chemistry and Application(Nos.LFCCMCA-01 and LFCCMCA-06)+1 种基金the Scientific Research Launch Project of Anhui Polytechnic University(No.2020YQQ057)the Scientific Research Project of Anhui Polytechnic University(No.Xjky2020090)。
文摘To date,Co-based metal-organic frameworks(Co-MOFs)have drawn much attention owing to their advantages of easy preparation,high porosity and adjustable structure.Because of these enticing properties,numerous efforts have been devoted to their applications in energy storage and conversion.However,poor conductivity has become one of the biggest obstacles for large-scale use of pristine Co-MOFs.Subsequently,many attempts have been carried out to develop various Co-MOF derived materials as electrodes for rechargeable batteries in order to address the above-mentioned shortcoming and to enhance the electrical conductivity with improved stability during cycling.Moreover,in addition to improvement of Li-ion batteries in practical utilization,seeking for other rechargeable batteries is another urgent task due to the high cost and limited sources of metallic Li.Herein,by following the recent research progress,this review provides an overview of applications of Co-MOF derived materials in various rechargeable batteries including lithium-ion batteries,sodium-ion batteries,lithium-sulfur batteries,zinc air batteries and other rechargeable batteries,where they have been utilized as cathodes,anodes,separators and electrocatalysts.Accordingly,we categorize and compare the morphology driven electrochemical performance of various Co-MOF derivatives including porous carbon,cobalt oxides,cobalt chalcogenides,cobalt phosphides and corresponding composites.Finally,current challenges for large-scale production and commercialization of Co-MOF derived materials as well as some reasonable solutions have been discussed at the end.