High-performance lithium-sulfur battery based on porous N-rich g-C_(3)N_(4) nan-otubes via a self-template method

The commercial development of lithium-sulfur batteries(Li-S)is severely limited by the shuttle effect of lithium polysulfides(LPSs)and the non-conductivity of sulfur.Herein,porous g-C_(3)N_(4) nanotubes(PCNNTs)are synthesized via a self-template method and utilized as an efficient sulfur host material.The one-dimensional PCNNTs have a high specific surface area(143.47 m^(2)·g^(-1))and an abundance of macro-/mesopores,which could achieve a high sulfur loading rate of 74.7wt%.A Li-S battery bearing the PCNNTs/S composite as a cathode displays a low capacity decay of 0.021% per cycle over 800 cycles at 0.5 C with an initial capacity of 704.8 mAh·g^(-1).PCNNTs with a tubular structure could alleviate the volume expansion caused by sulfur and lithium sulfide during charge/discharge cycling.High N contents could greatly enhance the adsorption capacity of the carbon nitride for LPSs.These synergistic effects contribute to the excellent cycling stability and rate performance of the PCNNTs/S composite electrode.

In-situ self-templated preparation of porous core-shell Fe_(1-x)S@N,S co-doped carbon architecture for highly efficient oxygen reduction reaction

Transition metal compound(TMC)/carbon hybrids,as prospering electrocatalyst,have attracted great attention in the field of oxygen reduction reaction(ORR).Their morphology,structure and composition often play a crucial role in determining the ORR performance.In this work,we for the first time report the successful fabrication of porous core-shell Fe_(1-x)S@N,S co-doped carbon(Fe_(1-x)S@NSC-t,t represents etching time)by a novel in-situ self-template induced strategy using Fe3O4 nanospheres and pyrrole as sacrificial self-template.The post-polymerization of pyrrole can be accomplished by the Fe^(3+)released through the etching of Fe_(3)O_(4) by HCl acid.Thus,the etching time has a significant effect on the morphology,structure,composition a nd ORR performance of Fe_(1-x)S@NSC-t.Based on the cha racterizations,we find Fe_(1-x)S@NSC-24 can realize effective and balanced combination of Fe_(1-x)S and NSC,possessing porous core-shell architecture,optimized structure defect,specific surface area and doped heteroatoms configurations(especially for pyridinic N,graphitic N and Fe-N structure).These features thus lead to outstanding catalytic activity and cycling stability towards ORR.Our work provides a good guidance on the design of TMC/carbon-based electrodes with unique stable morphology and optimized structure and composition.

Intramolecular Hydrogen Bond Self-template Synthesis of Some New Robson-type Macrocyclic Ligands

The intramolecular hydrogen bond self-template effect was suggested in the process of directly synthesizing the first six chiral metal-free Robson-type macrocyclic ligands. These ligands were characterized by H-1 NMR, IR, FAB-MS.

Self-template synthesis of peapod-like MnO@N-doped hollow carbon nanotubes as an advanced anode for lithium-ion batteries

The exploration of low-cost and high-performance transition metal oxides/carbon(TMOs/C)-based anodes to replace commercial graphite is still a huge challenge for the development of lithium-ion batteries(LIBs).In this work,MnO@N-doped hollow carbon nanotubes(MnO@NHCNT-v,v refers to the adding volume of pyrrole)hybrids are successfully prepared by a facile selftemplate strategy using Mn3O4 nanotubes(Mn3O4 NT)and pyrrole(PY)as the precursors.The morphology,structure and composition of these MnO@NHCNT-v samples are systematically investigated.And the effect of PY adding amounts on the synthesis of MnO@NHCNT-v samples is also explored.The results show that the Mn_(3)O_(4) NT works as a self-template,which releases Mn3+and guides the growth of polypyrrole(PPY)on Mn_(3)O_(4) NT.Meanwhile,it is demonstrated that the synthesis of MnO@NHCNTv hybrids can be well regulated by the added PY amounts.As a result,MnO@NHCNT-1 hybrid not only makes a good balance on the proportion of MnO and carbon matrix but also simultaneously obtains unique peapod-like structure and successful N doping in NHCNT,resulting in good electrical contact between the two components,enhanced chemical binding by Mn-N-C bonds and enough void space inside its microstructure.Benefitting from these merits,the resulting MnO@NHCNT-1 hybrid exhibits outstanding cycling stability and rate capability when used as a LIBs anode.Our work offers a good guidance on the design and preparation of low-price and high-performance TMOs/C-based LIBs anodes.

Self-templating synthesis of biomass-based porous carbon nanotubes for energy storage and catalytic degradation applications

Dwindling energy sources and a worsening environment are huge global problems,and biomass wastes are an under-exploited source of material for both energy and material generation.Herein,self-template decoction dregs of Ganoderma lucidum-derived porous carbon nanotubes(ST-DDLGCs)were synthesized via a facile and scalable strategy in response to these challenges.ST-DDLGCs exhibited a large surface area(1731.51 m^(2)g^(-1))and high pore volume(0.76 cm^(3)g^(-1)),due to the interlacing tubular structures of precursors and extra-hierarchical porous structures on tube walls.In the ST-DDLGC/PMS system,the degradation efficiency of capecitabine(CAP)reached~97.3%within 120 min.Moreover,ST-DDLGCs displayed high catalytic activity over a wide pH range of 3–9,and strong anti-interference to these typical and ubiquitous anions in wastewater and natural water bodies(i.e.,H_(2)PO_(4)^(-),NO_(3)^(-),Cl^(-) and HCO_(3)^(-)),in which a ^(1)O_(2)-dominated oxidation was identified and non-radical mechanisms were deduced.Additionally,ST-DDLGC-based coin-type symmetrical supercapacitors exhibited outstanding electrochemical performance,with specific capacitances of up to 328.1 F g^(-1)at 0.5 A g^(-1),and cycling stability of up to 98.6%after 10,000 cycles at a current density of 2 A g^(-1).The superior properties of ST-DDLGCs could be attributed to the unique porous tubular structure,which facilitated mass transfer and presented numerous active sites.The results highlight ST-DDLGCs as a potential candidate for constructing inexpensive and advanced environmentally functional materials and energy storage devices.

Facile self-template fabrication of hierarchical nickel-cobalt phosphide hollow nanoflowers with enhanced hydrogen generation performance

Developing facile methods to construct hierarchical-structured transition metal phosphides is beneficial for achieving high-efficiency hydrogen evolution catalysts.Herein,a self-template strategy of hydrothermal treatment of solid Ni-Co glycerate nanospheres followed by phosphorization is delivered to synthesize hierarchical Ni Co P hollow nanoflowers with ultrathin nanosheet assembly.The microstructure of Ni Co P can be availably tailored by adjusting the hydrothermal treatment temperature through affecting the hydrolysis process of Ni-Co glycerate nanospheres and the occurred Kirkendall effect.Benefitting from the promoted exposure of active sites and affluent mass diffusion routes,the HER performance of the Ni Co P hollow nanoflowers has been obviously enhanced in contrast with the solid Ni Co P nanospheres.The fabricated Ni Co P hollow nanoflowers yield the current density of 10 m A cmà2at small overpotentials of 95 and 127 m V in 0.5 mol Là1H2SO4and 1.0 mol Là1KOH solution,respectively.Moreover,the two-electrode alkaline cell assembled with the Ni Co P and Ir/C catalysts exhibits sustainable stability for overall water splitting.The work provides a simple but efficient method to regulate the microstructure of transition metal phosphides,which is helpful for achieving high-performance hydrogen evolution catalysts based on solid-state metal alkoxides.

Self-template synthesis of hierarchically structured Co3O4@NiO bifunctional electrodes for selective nitrate reduction and tetrahydroisoquinolines semidehydrogenation

The rational design and synthesis of hierarchically hollow nanostructures with controlled spatial architecture and composition are significant in electrocatalysis owing to their abundant active sites and the expedited electron/mass transfer.Electrocatalytic nitrate reduction to ammonia is of great interest from the points of environmental protection and energy saving.However,the development of this technology is hindered by the lack of efficient nitrate-toammonia electrocatalysts and the kinetically sluggish oxygen evolution reaction at the anode.Herein,a novel self-template conversion method was developed for the synthesis of Co3O4@Ni O hierarchical nanotubes(Co3O4@Ni O HNTs)with Ni O porous nanosheets assembled on Co3O4nanotubes.The as-obtained Co3O4@Ni O HNTs exhibited an outstanding performance for both the cathodic nitrate electroreduction to ammonia reaction and the anodic tetrahydroisoquinolines(THIQs)semi-dehydrogenation to dihydroisoquinolines(DHIQs).Importantly,a two-electrode system of Co3O4@Ni O HNTs||Co3O4@Ni O HNTs was constructed for the simultaneous synthesis of ammonia and DHIQs with high selectivity and robust stability.

Self-templated formation of cobalt-embedded hollow N-doped carbon spheres for efficient oxygen reduction

The slow kinetics at the cathode of oxygen reduction reaction(ORR)seriously limits the efficiencies of fuel cells and metal-air batteries.Pt,the state-of-the-art ORR electrocatalyst,suffers from high cost,low earth abundance,and poor stability.Here a self-templated strategy based on metal-organic frameworks(MOFs)is proposed for the fabrication of hollow nitrogen-doped carbon spheres that are embedded with cobalt nanoparticles(Co/HNC).The Co/HNC manifests better ORR activities,methanol tolerance,and stability than commercial Pt/C.The high ORR performance of Co/NHC can be attributed to the hollow structure which provides enlarged electrochemically active surface area,the formation of more Co-N species,and the introduction of defects.This work highlights the significance of rational engineering of MOFs for enhanced ORR activity and stability and offers new routes to the design and synthesis of high-performance electrocatalysts.

Co_3O_4 nanosheet-built hollow dodecahedrons via a two-step self-templated method and their multifunctional applications

TheCo3O4 nanosheet-built hollow dodecahedrons(Co3 O4 NSHDs) were fabricated via a controllable twostep self-templated method. The ZIF-67 dodecahedrons were prepared as first self-template to synthesize the Co-LDH hollow dodecahedrons, which were further used as self-template to fabricateCo3O4 NSHDs by a controlled calcination.The proposed two-step self-templated method not only brings hollow structures without auxiliary template, ultrathin nanosheet, ultrafine grains, and large surface areas, but also allows the easy and uniform surface modification, as demonstrated of PdO modification. TheCo3O4 NSHDs with above features could show multifunctional applications, such as sensing and catalysis. Experiments suggest that theCo3O4 NSHDs show good gas sensing performances to trimethylamine at a low operating temperature(100 oC). They can be further enhanced by PdO surface modification, which have a low detection limit(250 ppb) and a short response time(4.5 s).In addition, theCo3O4 NSHDs exhibited excellent oxygen evolution reaction performances with a low overpotential of359 mV, low Tafel slope of 80.7 mV dec-1 and low electrochemical impedance, which was superior to those for theCo3O4 NCs obtained by directly calcinating the ZIF-67 templates,Ni foam and most common metal oxides catalysts.

Self-templated formation of twin-like metal-organic framework nanobricks as pre-catalysts for efficient water oxidation

Fabrication of single-crystalline metal-organic framework(MOF)hollow nanostructures with two-dimensional(2D)morphologies is a challenging task.Herein,twin-like MOF nanobricks,a quasi-hollow 2D architecture,with multi-metal nodes and replaceable organic ligands,are uniformly and firmly grown on conductive Ni foam through a generic one-pot approach.The formation process of twin-like MOF nanobricks mainly includes selective epitaxial growth of Fe-rich MOF layer and simultaneously dissolution of the pre-formed Ni-rich metal-organic frameworks(MOFs),all of which can be ascribed to a special self-templated mechanism.The fantastic structural merits of twin-like MOF nanobrick arrays,featuring highly exposed active sites,remarkable electrical conductivity,and hierarchical porosities,enable this material for efficient electrocatalysis.Using bimetallic NiFe-MOFs grown on Ni foam as an example,the resultant twin-like nanobrick arrays can be directly utilized as three-dimensional(3D)integrated electrode for high-performance water oxidation in 1 M KOH with a low overpotential,fast reaction kinetics(28.5 mV·dec^(-1)),and superb stability.Interestingly,the unstable NiFe-MOFs were served as an oxygen evolution reaction(OER)pre-catalyst and the single-crystalline NiFe-MOF precursor can be in-situ topochemically regulated into porous and lowcrystalline NiFeOx nanosheets during the OER process.This work extends the hollowing strategy to fabricate hollow MOFs with 2D architectures and highlights their direct utilization for advanced electrocatalysis.

Self-template synthesis of double-layered porous nanotubes with spatially separated photoredox surfaces for efficient photocatalytic hydrogen production

Improving charge carriers separation to achieve high photoconversion efficiency in heterogeneous photocatalysts is highly desirable.Herein,heterostructured ZnS@CdS double-layered porous nanotubes(PNTs),in which the spatially separated reduction and oxidation reaction sites lie on the outer and inner shell,respectively,are fabricated through a robust self-template conversion strategy.After selective photo-deposition of Ni and CoO_x as dual cocatalysts,Ni nanoparticles as electron collectors and reduction reaction sites are loaded on the outer shell,while CoO_x nanoparticles as hole collectors and oxidation reaction sites are loaded on the inner shells.As a result,a novel CoO_x/ZnS@CdS/Ni photocatalyst is obtained and shows high visible-light-driven photocatalytic hydrogen production activity owing to the synergistic effect of self-template-derived thin mesoporous heterojunctions and photo-depositionderived spatially separated dual cocatalysts,which can significantly provide driving force for the ordered transfer of photogenerated electrons and holes toward opposite direction and promote the surface catalytic reaction.Additionally,the facile strategy can be broadened to the preparation of CoO_x/ZnSe@CdSe/NiPNTs with enhanced photocatalytic activity.

Self-templated covalent functionalization of graphitic surfaces with a quasi-periodic pattern

Patterned covalent functionalization of graphitic surfaces(GSs)is of interest in the development of devices and nanocomposite materials.In contrast to the strategies using external templates or control for realizing patterned covalent functionalization of GSs,here,we present a self-templated strategy by exploiting the synergistic effects of chemical and physical functionalization of GSs.Therefore,a diazonium salt is reduced by potassium iodide(KI)in dimethyl sulfoxide while the solution is in contact with a GS,resulting in its spatially heterogeneous,that is,chemical and physical,functionalization.This heterogeneous functionalization leads to a quasiperiodic pattern of striped corrals with three equivalent orientations in the covalent layer.The formation of the striped corrals is ascribed to physisorbed domains formed by self-assembled N_(2),which is produced in situ during the reduction of the diazonium salt,preventing the covalent functionalization.

Synthesis of Octylmethoxycinamate-silica Core-shell Nanoparticles with Self-templating Method

t A self-templating method was employed to synthesize core-shell nanoparticles with octylmethoxycinamate（OMC）, a well-known organic UV absorber, as core and nanosilica particles as shell. The characteristic of this method is that the whole process requires neither surface treatment for nanosilica particles nor additional surfactant or stabilizer, and all the reactions could be finished in one-pot, which exempts removing template and reduces reaction steps compared to the conventional process. The morphology, structure, particle size distribution, chemical composition and optical property of OMC-SiO2 nanoparticles were characterized by scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, dynamic light scattering（DLS）, FTIR spectrometry and UV absorption spectrometry, respectively. Experiment results indicate that the resulting OMC-SiO2 nanoparticles were perfectly spherical with smooth particle surfaces, and had clear core-shell structures. The particle size could be tuned by altering reaction conditions. In addition, the mechanism of the self-templating method for forming core-shell nanoparticles was discussed.

Novel Bilayer-Shelled N,O-Doped Hollow Porous Carbon Microspheres as High Performance Anode for Potassium-Ion Hybrid Capacitors

With the advantages of high energy/power density,long cycling life and low cost,dual-carbon potassium ion hybrid capacitors(PIHCs)have great potential in the field of energy storage.Here,a novel bilayer-shelled N,O-doped hollow porous carbon microspheres(NOHPC)anode has been prepared by a self-template method,which is consisted of a dense thin shell and a hollow porous spherical core.Excitingly,the NOHPC anode possesses a high K-storage capacity of 325.9 mA h g^(−1)at 0.1 A g^(−1)and a capacity of 201.1 mAh g^(−1)at 5 A g^(−1)after 6000 cycles.In combination with ex situ characterizations and density functional theory calculations,the high reversible capacity has been demonstrated to be attributed to the co-doping of N/O heteroatoms and porous structure improved K+adsorption and intercalation capabilities,and the stable long-cycling performance originating from the bilayer-shelled hollow porous carbon sphere structure.Meanwhile,the hollow porous activated carbon microspheres(HPAC)cathode with a high specific surface area(1472.65 m^(2)g^(−1))deriving from etching NOHPC with KOH,contributing to a high electrochemical adsorption capacity of 71.2 mAh g^(−1)at 1 A g^(−1).Notably,the NOHPC//HPAC PIHC delivers a high energy density of 90.1 Wh kg^(−1)at a power density of 939.6 W kg^(−1)after 6000 consecutive charge-discharge cycles.

Porous palladium phosphide nanotubes for formic acid electrooxidation

The development of an efficient catalyst for formic acid electrocatalytic oxidation reaction(FAEOR)is of great significance to accelerate the commercial application of direct formic acid fuel cells(DFAFC).Herein,palladium phosphide(PdxPy)porous nanotubes(PNTs)with different phosphide content(i.e.,Pd3P and Pd5P2)are prepared by combining the self-template reduction method of dimethylglyoxime-Pd(II)complex nanorods and succedent phosphating treatment.During the reduction process,the self-removal of the template and the continual inside-outside Ostwald ripening phenomenon are responsible for the generation of the one-dimensional hollow and porous architecture.On the basis of the unique synthetic procedure and structural advantages,Pd3P PNTs with optimized phos phide content show outstanding electroactivity and stability for FAEOR.Im portantly,the strong electronic effect between Pd and P promotes the direct pathway of FAEOR and inhibits the occurrence of the formic acid decomposition reaction,which effectively enhances the FAEOR electroactivity of Pd3P PNTs.In view of the facial synthesis,excellent electroactivity,high stability,and unordinary selectivity,Pd3P PNTs have the potential to be an efficient anode electrocatalyst for DFAFC.

Synthesis of Size-Controllable NiCo2S4 Hollow Nanospheres Toward Enhanced Electrochemical Performance

Although the synthesis of novel nanostructured metal sulfides has been well established,further size-controllable optimization is still valuable to enhance their performance for various applications.Herein,a self-template method to size-controllably synthesize the hollow NiCo2S4 nanospheres is reported.Uniformly monodisperse Ni Co precursors with diameter widely ranging from 97 to 550 nm are controllably synthesized and subsequently transformed into hollow NiCo2S4 nanospheres through in situ sulfidation.Smaller nanoparticles’diameter results in the hollow NiCo2S4 nanospheres larger surface area and thinner shell thickness and hence provides much more electrochemical active sites as well as facilitate the ion and electron transfer.Consequently,the hollow NiCo2S4 nanospheres—used as the electrode materials in supercapacitors—achieve 19%enhancement of specific capacity from 484.8 to 575.1 C g-1 through lowering the 42.5%diameter of hollow NiCo2S4 nanospheres from 407 to 234 nm.Moreover,the hollow NiCo2S4 nanospheres with 234 nm diameter exhibit superior rate capacity indicated by 49%capacity retention from 1 to 50 A g-1 and excellent cycling stability(77%after 2000 cycles).Furthermore,this method is a potentially general strategy in the size-controllable synthesis of the metal sulfides hollow nanostructures and results in the remarkable electrochemical applications.

3D-honeycomb carbons for high performance electrical double layer capacitors electrodes

Sodium fulvic acid based hierarchical porous carbons(SFA-HPCs) with a specific surface area of 1919 m^2·g^(–1) and total volume of 1.7 cm^3·g^(–1) has been synthesized by a simple self-template method. The carbon skeleton can be formatted by the decomposition process of sodium fulvic acid(SFA) in a N_2 atmosphere. The sodium compund in SFA is used as a self-template to create the hierarchical porous structure. The unique hierarchical structure of SFA-HPCs provides an efficient pathway for electrolyte ions to be diffused into the internal surfaces of bulk electrode particles. It results in a high charge storage capacitance of 186 F·g^(–1) at current load of 40 A·g^(–1). The capacitance of 230 F·g^(–1) at 0.05 A·g^(–1) and 186 F·g^(–1) at 40 A·g^(–1) show its good rate capability. Besides, it also achieves desirable cycling stability, 99.4% capacitance remained after 10000 cycles at 40 A·g^(–1).

Self-templating construction of hollow microspheres assembled by nanosheets with exposed active planes for sodium ion storage

P2-type layered metal oxides have been considered as one of the promising cathode candidates for high-performance Na-ion batteries(SIBs).However,it is still challenging to balance the contradiction of high energy density and long cycle life due to the structural degradation and sluggish ion diffusion dynamics.Here,the hierarchical P2-Na2/3Ni1/3Mn2/3O2 hollow microspheres assembled by nanosheets are constructed via a self-template approach.The obtained nanosheets with more exposed electrochemical active planes serving as desodiation/sodiation reactors can provide substantial Na+channels,shorten the diffusion pathways,and accommodate the volume changes during charge/discharge process.Benefiting from the facile Na+diffusion paths and optimal architecture modulation,the cathode delivers a high initial Coulombic efficiency of 96.0%with a high energy density of 299.7 Wh·kg^(−1).The highly reversible structural evolutions processes are verified by galvanostatic intermittent titration technique(GITT)and operando electrochemical impedance spectroscopy(EIS)measurement,which would significantly improve the cycle stability(83.3%capacity retention at 1.0 C over 500 loops).Furthermore,the full cell assembled by hard carbon presents a high reversible capacity of 71 mAh·g^(−1)at 0.2 C and promising capacity retention(91.5%after 50 cycles).The designing concept of morphological configuration in this work paves an accessible route for building high-performance electrode materials.

Self-templating synthesis of Pd_(4)S hollow nanospheres as electrocatalysts for oxygen reduction reaction

Hollow nanostructures with structural advantages have been widely exploited as catalysts in electrochemical reactions.However,there are only limited strategies for constructing hollow Pd-based nanostructures.In this work,Pd4S hollow nanospheres(Pd4S HNSs)are synthesized with a facile wet-chemical method via a self-templating process.Intermediate Pd-L-cysteine solid nanospheres(SNSs)were firstly obtained by the coordination of L-cysteine with Pd^(2+),and then in situ converted to hollow nanospheres in the following reduction process.The formation mechanism of the Pd4S HNSs was studied,and the size of the Pd4S HNSs can be readily adjusted by tuning the size of the SNSs.The hollow morphology would help the exposure of active sites and the prevention of aggregation during the catalytic reactions.As a result,the Pd4S HNSs exhibit improved catalytic performances in the oxygen reduction reactions,with a half-wave potential of 0.913 V vs.reversible hydrogen electrode(RHE)and impressive stability in the accelerated durability test.

In-situ self-templating synthesis of 3D hierarchical porous carbonsfrom oxygen-bridged porous organic polymers for highperformance supercapacitors

It is a big challenge to well control the porous structure of carbon materials for supercapacitor application.Herein,a simple in-situ self-templating strategy is developed to prepare three-dimensional(3D)hierarchical porous carbons with good combination of micro and meso-porous architecture derived from a new oxygen-bridged porous organic polymer(OPOP).The OPOP is produced by the condensation polymerization of cyanuric chloride and hydroquinone in NaOH ethanol solution and NaCl is in-situ formed as by-product that will serve as template to construct an interconnected 3D hierarchical porous architecture upon carbonization.The large interface pore architecture,and rich doping of N and O heteroatoms effectively promote the electrolyte accessibility and electronic conductivity,and provide abundant active sites for energy storage.Consequently,the supercapacitors based on the optimized OPOP-800 sample display an energy density of 8.44 and 27.28 Wh·kg^(−1)in 6.0 M KOH and 1.0 M Na2SO4 electrolytes,respectively.The capacitance retention is more than 94%after 10,000 cycles.Furthermore,density functional theory(DFT)calculations have been employed to unveil the charge storage mechanism in the OPOP-800.The results presented in this job are inspiring in finely tuning the porous structure to optimize the supercapacitive performance of carbon materials.