Sodium-ion batteries(SIBs) and hybrid capacitors(SIHCs) have garnered significant attention in energy storage due to their inherent advantages,including high energy density,cost-effectiveness,and enhanced safety.Howev...Sodium-ion batteries(SIBs) and hybrid capacitors(SIHCs) have garnered significant attention in energy storage due to their inherent advantages,including high energy density,cost-effectiveness,and enhanced safety.However,developing high-performance anode materials to improve sodium storage performa nce still remains a major challenge.Here,a facile one-pot method has been developed to fabricate a hybrid of MoSeTe nanosheets implanted within the N,F co-doped honeycomb carbon skeleton(MoSeTe/N,F@C).Experimental results demonstrate that the incorporation of large-sized Te atoms into MoSeTe nanosheets enlarges the layer spacing and creates abundant anion vacancies,which effectively facilitate the insertion/extraction of Na^(+) and provide numerous ion adsorption sites for rapid surface capacitive behavior.Additionally,the heteroatoms N,F co-doped honeycomb carbon skeleton with a highly conductive network can restrain the volume expansion and boost reaction kinetics within the electrode.As anticipated,the MoSeTe/N,F@C anode exhibits high reversible capacities along with exceptional cycle stability.When coupled with Na_(3)V_(2)(PO_(4))_(3)@C(NVPF@C) to form SIB full cells,the anode delivers a reversible specific capacity of 126 mA h g^(-1) after 100 cycles at 0.1 A g^(-1).Furthermore,when combined with AC to form SIHC full cells,the anode demonstrates excellent cycling stability with a reversible specific capacity of50 mA h g^(-1) keeping over 3700 cycles at 1.0 A g^(-1).In situ XRD,ex situ TEM characterization,and theoretical calculations(DFT) further confirm the reversibility of sodium storage in MoSeTe/N,F@C anode materials during electrochemical reactions,highlighting their potential for widespread practical application.This work provides new insights into the promising utilization of advanced transition metal dichalcogenides as anode materials for Na^(+)-based energy storage devices.展开更多
S and Co co-doped carbon catalysts were prepared via pyrolysis of MOF-71 and thiourea mixtures at 800℃at a mass ratio of MOF-71 to thiourea of 1:0.1 to effectively activate peroxymonosulfate(PMS)for methylene blue(MB...S and Co co-doped carbon catalysts were prepared via pyrolysis of MOF-71 and thiourea mixtures at 800℃at a mass ratio of MOF-71 to thiourea of 1:0.1 to effectively activate peroxymonosulfate(PMS)for methylene blue(MB)degradation.The effects of two different mixing routes were identified on the MB degradation performance.Particularly,the catalyst obtained by the alcohol solvent evaporation(MOF-AEP)mixing route could degrade 95.60%MB(50 mg/L)within 4 min(degradation rate:K=0.78 min^(-1)),which was faster than that derived from the direct grinding method(MOF-DGP,80.97%,K=0.39 min^(-1)).X-ray photoelectron spectroscopy revealed that the Co-S content of MOF-AEP(43.39at%)was less than that of MOF-DGP(54.73at%),and the proportion of C-S-C in MOF-AEP(13.56at%)was higher than that of MOF-DGP(10.67at%).Density functional theory calculations revealed that the adsorption energy of Co for PMS was -2.94 eV when sulfur was doped as C-S-C on the carbon skeleton,which was higher than that when sulfur was doped next to cobalt in the form of Co-S bond(-2.86 eV).Thus,the C-S-C sites might provide more contributions to activate PMS compared with Co-S.Furthermore,the degradation parameters,including pH and MOF-AEP dosage,were investigated.Finally,radical quenching experiments and electron paramagnetic resonance(EPR)measurements revealed that ^(1)O_(2)might be the primary catalytic species,whereas·O~(2-)might be the secondary one in degrading MB.展开更多
The development of simple and effective strategies to prepare electrocatalysts,which possess unique and stable structures comprised of metal/nonmetallic atoms for oxygen reduction reaction(ORR)and oxygen evolution rea...The development of simple and effective strategies to prepare electrocatalysts,which possess unique and stable structures comprised of metal/nonmetallic atoms for oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),is currently an urgent issue.Herein,an efficient bifunctional electrocatalyst featured by ultralong N,S-doped carbon nano-hollow-sphere chains about 1300 nm with encapsulated Co nanoparticles(Co-CNHSCs)is developed.The multifunctional catalytic properties of Co together with the heteroatom-induced charge redistribution(i.e.,modulating the electronic structure of the active site)result in superior catalytic activities toward OER and ORR in alkaline media.The optimized catalyst Co-CNHSC-3 displays an outstanding electrocatalytic ability for ORR and OER,a high specific capacity of 1023.6 mAh gZn^(-1),and excellent reversibility after 80 h at 10mA cm^(-2)in a Zn-air battery system.This work presents a new strategy for the design and synthesis of efficient multifunctional carbon-based catalysts for energy storage and conversion devices.展开更多
Hollow nanostructures with external shells and inner voids have been proved to greatly shorten the transport distance of ions/electrons and buffer volume change,especially for the large-sized potassium-ions in seconda...Hollow nanostructures with external shells and inner voids have been proved to greatly shorten the transport distance of ions/electrons and buffer volume change,especially for the large-sized potassium-ions in secondary batteries.In this work,hollow carbon(HC) nanospheres embedded with S,P co-doped NiSe_(2)nanoparticles are fabricated by "drop and dry" and "dissolving and precipitation" processes to form Ni(OH)2nanocrystals followed by annealing with S and P dopants to form nanoparticles.The resultant S,P-NiSe_(2)/HC composite exhibits excellent cyclic performance with 131.6 mA h g^(-1)at1000 mA g^(-1)after 3000 cycles for K^(+)storage and a capacity of 417.1 mA h g^(-1)at 1000 mA g^(-1)after1000 cycles for Li^(+)storage.K-ion full cells are assembled and deliver superior cycling stability with a ca pacity of 72.5 mA h g^(-1)at 200 mA g^(-1)after 500 cycles.The hollow carbon shell with excellent electrical conductivity effectively promotes the transporta tion and tolerates large volume variation for both K^(+)and Li^(+).Density functional theory calculations confirm that the S and P co-doping NiSe_(2) enables stronger adsorption of K^(+)ions and higher electrical conductivity that contributes to the improved electrochemical performance.展开更多
Hydrodeoxygenation of furfural(FF)into 2-methylfuran(MF)is a significant biomass utilization route.However,designing efficient and stable non-noble metal catalyst is still a huge challenge.Herein,we reported the N,O c...Hydrodeoxygenation of furfural(FF)into 2-methylfuran(MF)is a significant biomass utilization route.However,designing efficient and stable non-noble metal catalyst is still a huge challenge.Herein,we reported the N,O co-doped carbon anchored with Co nanoparticles(Co-SFB)synthesized by employing the organic ligands with the target heteroatoms.Raman,electron paramagnetic resonance(EPR),electrochemical impedance spectroscopy(EIS),and X-ray photoelectron spectroscopy(XPS)characterizations showed that the co-doping of N and O heteroatoms in the carbon support endows Co-SFB with enriched lone pair electrons,fast electron transfer ability,and strong metal-support interaction.These electronic properties resulted in strong FF adsorption as well as lower apparent reaction activation energy.At last,the obtained N,O co-doped Co/C catalyst showed excellent catalytic activity(nearly 100 mol%FF conversion and 94.6 mol%MF yield)and stability for in-situ dehydrogenation of FF into MF.This N,O co-doping strategy for the synthesis of highly efficient catalytic materials with controllable electronic state will provide an excellent opportunity to better understand the structure-function relationship.展开更多
Renewable lignin used for synthesizing materials has been proven to be highly potential in specific electrochemistry.Here,we report a simple method to synthesize nitrogen and sulfur co-doped carbon nanosheets by using...Renewable lignin used for synthesizing materials has been proven to be highly potential in specific electrochemistry.Here,we report a simple method to synthesize nitrogen and sulfur co-doped carbon nanosheets by using bagasse lignin,denoted as lignin-derived carbon(LC).By adjusting the ratio of nitrogen source and annealing temperature,we obtained the ultrathin graphitic lignin carbon(LC-4-1000)with abundant wrinkles with high surface area of 1208 m2g_1 and large pore volume of 1.40 cm3g_1.In alkaline medium,LC-4-1000 has more positive half-wave potential and nearly current density compared to commercial Pt/C for oxygen reduction reaction(ORR).More importantly,LC-4-1000 also exhibits comparable activity and superior stability for ORR in acid medium due to its high graphitic N ratio and a direct four electron pathway for ORR.This study develops a cost-effective and highly efficient method to prepare biocarbon catalyst for ORR in fuel cells.展开更多
Exploring inexpensive and efficient bifunctional electrocatalysts for oxygen reduction reaction(ORR) and oxygen evolution reaction(OER) is critical for rechargeable metal-air batteries. Herein, we report a new 3D hier...Exploring inexpensive and efficient bifunctional electrocatalysts for oxygen reduction reaction(ORR) and oxygen evolution reaction(OER) is critical for rechargeable metal-air batteries. Herein, we report a new 3D hierarchical sulfur and nitrogen co-doped carbon nanocages(hSNCNC) as a promising bifunctional oxygen electrocatalyst by an in-situ MgO template method with pyridine and thiophene as the mixed precursor. The as-prepared h SNCNC exhibits a positive half-wave potential of 0.792 V(vs. reversible hydrogen electrode, RHE) for ORR, and a low operating potential of 1.640 V at a 10 mA cm-2 current density for OER. The reversible oxygen electrode index is 0.847 V, far superior to commercial Pt/C and IrO2,which reaches the top level of the reported bifunctional catalysts. Consequently, the hSNCNC as air cathodes in an assembled Zn-air battery features low charge/discharge overpotential and long lifetime. The remarkable properties arises from the introduced multiple heteroatom dopants and stable 3D hierarchical structure with multi-scale pores, which provides the abundant uniform high-active S and N species and efficient charge transfer as well as mass transportation. These results demonstrate the potential strategy in developing suitable carbon-based bi-/multi-functional catalysts to enable the next generation of the rechargeable metal-air batteries.展开更多
The interface mechanism between catalyst and carbon substrate has been the focus of research.In this paper,the FeCo alloy embedded N,S co-doped carbon substrate bifunctional catalyst(FeCo/S-NC)is obtained by a simple ...The interface mechanism between catalyst and carbon substrate has been the focus of research.In this paper,the FeCo alloy embedded N,S co-doped carbon substrate bifunctional catalyst(FeCo/S-NC)is obtained by a simple one-step pyrolysis strategy.The experimental results and density functional theory(DFT)calculation show that the formation of FeCo alloy is conducive to promoting electron transfer,and the introduction of S atom can enhance the interaction between FeCo alloy and carbon substrate,thus inhibiting the migration and agglomeration of particles on the surface of carbon material.The FeCo/SNC catalysts show outstanding performance for oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).FeCo/S-NC shows a high half-wave potential(E_(1/2)=0.8823 V)for ORR and a low overpotential at 10 mA cm^(-2)(E_(j=10)=299 mV)for OER.In addition,compared with Pt/C+RuO_(2) assembled Zn-air battery(ZAB),the FeCo/S-NC assembled ZAB exhibits a larger power density(198.8 mW cm^(-2)),a higher specific capacity(786.1 mA h g_(zn)~(-1)),and ultra-stable cycle performance.These results confirm that the optimized composition and the interfacial interaction between catalyst and carbon substrate synergistically enhance the electrochemical performance.展开更多
Oxidized asphaltene (OA), a thermosetting material with plenty of functional groups, is synthesized from asphaltene (A) using HNO3]HzSO4 as the oxidizing agent. Boron, nitrogen co-doped porous carbon (BNC-OA) is...Oxidized asphaltene (OA), a thermosetting material with plenty of functional groups, is synthesized from asphaltene (A) using HNO3]HzSO4 as the oxidizing agent. Boron, nitrogen co-doped porous carbon (BNC-OA) is prepared by carbonization of the mixture of boric acid and OA at 1173 K in an argon atmosphere. X-ray photoelectron spectroscopy (XPS) characterization reveals that the BNC-OA has a nitrogen content of 3.26 at.% and a boron content of 1.31 at.%, while its oxidation-free counterpart (BNC-SA) has a nitrogen content of 1.61 at.% and a boron content of 3.02 at.%. The specific surface area and total pore volume of BNC-OA are 1103 m2·g^-1 and 0.921 cm3·g^-1, respectively. At a current density of 0.1 A·g^-1, the specific capacitance of BNC-OA is 335 F·g^-1 and the capacitance retention can still reach 83% at 1 A·g^-1. The analysis shows that the superior electrochemical performance of the BNC-OA is attributed to the pseudocapacitance behavior of surface heteroatom functional groups and an abundant pore-structure. Boron, nitrogen co-doped porous carbon is a promising electrode material for supercapacitors.展开更多
Silicon-based(Si)materials are promising anodes for lithium-ion batteries(LIBs)because of their ultrahigh theoretical capacity of 4200 mA h g^(−1).However,commercial applications of Si anodes have been hindered by the...Silicon-based(Si)materials are promising anodes for lithium-ion batteries(LIBs)because of their ultrahigh theoretical capacity of 4200 mA h g^(−1).However,commercial applications of Si anodes have been hindered by their drastic volume variation(∼300%)and low electrical conductivity.Here,to tackle the drawbacks,a hierarchical Si anode with double-layer coatings of a SiOx inner layer and a nitrogen(N),boron(B)co-doped carbon(C-NB)outer layer is elaborately designed by copyrolysis of Si-OH structures and a H3BO_(3)-doped polyaniline polymer on the Si surface.Compared with the pristine Si anodes(7mA h g^(−1) at 0.5 A g^(−1) after 340 cycles and 340 mA h g^(−1) at 5 A g^(−1)),the modified Si-based materials(Si@SiOx@C-NB nanospheres)present su perior cycling stability(reversible 1301 mA h g^(−1) at 0.5 A g^(−1) after 340 cycles)as well as excellent rate capability(690mA h g^(−1) at 5 A g^(−1))when used as anodes in LIBs.The unique double-layer coating structure,in which the inner amorphous SiOx layer acts as a buffer matrix and the outer defect-rich carbon enhances the electron diffusion of the whole anode,makes it possible to de liver excellent electrochemical properties.These results indicate that our double-layer coating strategy is a promising approach not only for the devel opment of sustainable Si anodes but also for the design of multielement-doped carbon nanomaterials.展开更多
Biomass-derived carbon has demonstrated great potentials as advanced electrode for capacitive deionization(CDI),owing to good electroconductivity,easy availability,intrinsic pores/channels.However,conventional simple ...Biomass-derived carbon has demonstrated great potentials as advanced electrode for capacitive deionization(CDI),owing to good electroconductivity,easy availability,intrinsic pores/channels.However,conventional simple pyrolysis of biomass always generates inadequate porosity with limited surface area.Moreover,biomass-derived carbon also suffers from poor wettability and single physical adsorption of ions,resulting in limited desalination performance.Herein,pore structure optimization and element co-doping are integrated on banana peels(BP)-derived carbon to construct hierarchically porous and B,N co-doped carbon with large ions-accessible surface area.A unique expansionactivation(EA)strategy is proposed to modulate the porosity and specific surface area of carbon.Furthermore,B,N co-doping could increase the ions-accessible sites with improved hydrophilicity,and promote ions adsorption.Benefitting from the synergistic effect of hierarchical porosity and B,N co-doping,the resultant electrode manifest enhanced CDI performance for NaCl with large desalination capacity(29.5 mg g^(-1)),high salt adsorption rate(6.2 mg g^(-1)min^(-1)),and versatile adsorption ability for other salts.Density functional theory reveals the enhanced deionization mechanism by pore and B,N co-doping.This work proposes a facile EA strategy for pore structure modulation of biomass-derived carbon,and demonstrates great potentials of integrating pore and heteroatoms-doping on constructing high-performance CDI electrode.展开更多
Developing high power and energy supercapacitors(SCs)is a long-pursued goal for the application in transportation and energy storage station.Herein,a rationally-designed Co-doped nickel oxide nanosheets@carbon-welded ...Developing high power and energy supercapacitors(SCs)is a long-pursued goal for the application in transportation and energy storage station.Herein,a rationally-designed Co-doped nickel oxide nanosheets@carbon-welded carbon nanotube foam(Co-doped NiO@WCNTF)as freestanding electrode is successfully prepared for high power and energy SCs.The WCNTF framework with high specific surface area provides three dimensional highly conductive network for fast charge transport and ensures high loading of active materials(9.2 mg/cm2).Moreover,porous Co-doped NiO nanosheets uniformly anchored on the WCNTF framework enable rapid charge kinetics due to the high intrinsic conductivity of Co-doped Ni O nanosheets and their good contact with conductive WCNTF substrate.As a result,the unique integrated electrode with 3D architecture exhibits an ultrahigh specific capacitance of 11.45 F/cm2 at 5 mA/cm2,outstanding rate capability(11.45 F/cm2 at 5 mA/cm2 and a capacitance retention of 86.2%at 30 mA/cm2)and good cycling stability,suggesting great potential for high performance supercapacitor.展开更多
Direct synthesis of high-quality doped graphene on dielectric substrates without transfer is highly desired for simplified device processing in electronic applications.However,graphene synthesis directly on substrates...Direct synthesis of high-quality doped graphene on dielectric substrates without transfer is highly desired for simplified device processing in electronic applications.However,graphene synthesis directly on substrates suitable for device applications,though highly demanded,remains unattainable and challenging.Here,a simple and transfer-free synthesis of high-quality doped graphene on the dielectric substrate has been developed using a thin Cu layer as the top catalyst and polycyclic aromatic hydrocarbons as both carbon precursors and doping sources.N-doped and N,F-co-doped graphene have been achieved using TPB and F16Cu Pc as solid carbon sources,respectively.The growth conditions were systematically optimized and the as-grown doped graphene were well characterized.The growth strategy provides a controllable transfer-free route for high-quality doped graphene synthesis,which will facilitate the practical applications of graphene.展开更多
Among various anode candidates for potassium-ion batteries,carbonaceous materials have attracted significant attention due to their overwhelming advantages including cost-effectiveness and environmental benignity.Howe...Among various anode candidates for potassium-ion batteries,carbonaceous materials have attracted significant attention due to their overwhelming advantages including cost-effectiveness and environmental benignity.However,the inferior specific capacity and the sluggish reaction kinetics hinder the further development in this realm.Herein,we report biomass templated synthesis of boron/oxygen heteroatom co-doped carbon particles(BO-CPs)via direct plasma-enhanced chemical vapor deposition.With the combined advantages of abundant active sites,large accessible surface area,and functional groups,BO-CP anode exhibits high reversible specific capacity(426.5 mAh g^(-1)at 0.1 A g^(-1))and excellent rate performance(166.5 mAh g^(-1)at 5 A g^(-1)).The K-ion storage mechanism is probed by operando Raman spectroscopy,ex situ X-ray photoelectron spectroscopy/electrochemical impedance spectroscopy,galvanostatic intermittent titration technique measurements,and theoretical simulations.The synergistic effect of boron and oxygen co-doping greatly facilitates the performance of carbon-based anode,wherein boron dopant improves the conductivity of carbon framework and the oxygen dopant affords ample active sites and thus harvests additional specific capacity.This work is anticipated to propel the development of high-performance anode materials for emerging energy storage devices.展开更多
Oxygen reduction reaction (ORR) is an important process for the conversion and utilization of a wide range of renewable energy sources, and is critical for the shape of future energy scenario [1–10]. However, ORR is ...Oxygen reduction reaction (ORR) is an important process for the conversion and utilization of a wide range of renewable energy sources, and is critical for the shape of future energy scenario [1–10]. However, ORR is a complex four-electron transfer process and is kinetically sluggish. It is urgent to develop high-efficient electrocatalysts to solve this problem [11–15]. Up to now, precious metal-based catalysts such as Pt-based electrocatalysts have been widely studied and found to be one of the most efficient electrocatalysts for ORR. However, the high price and the small reserves limit their large-scale commercialization [10,16–23]. Therefore, in order to fulfill needs for the practical applications, it is necessary to develop low-cost electrocatalysts, also with high activity and great stability [19,24–28].展开更多
Sodium-ion capacitors(SICs)have received increasing interest for grid stationary energy storage application due to their affordability,high power,and energy densities.The major challenge for SICs is to overcome the ki...Sodium-ion capacitors(SICs)have received increasing interest for grid stationary energy storage application due to their affordability,high power,and energy densities.The major challenge for SICs is to overcome the kinetics imbalance between faradaic anode and nonfaradaic cathode.To boost the Na+reaction kinetics,the present work demonstrated a high-rate MnS-based anode by embedding the MnS nanocrystals into the N,S-co-doped carbon matrix(MnS@NSC).Benefiting from the fast pseudocapacitive Na+storage behavior,the resulting composite exhibits extraordinary rate capability(205.6 mAh g−1 at 10 A g−1)and outstanding cycling stability without notable degradation after 2000 cycles.A prototype SIC was demonstrated using MnS@NSC anode and N-doped porous carbon(NC)cathode;the obtained hybrid SIC device can display a high energy density of 139.8 Wh kg−1 and high power density of 11,500 W kg−1,as well as excellent cyclability with 84.5%capacitance retention after 3000 cycles.The superior electrochemical performance is contributed to downsizing of MnS and encapsulation of conductive N,S-co-doped carbon matrix,which not only promote the Na+and electrons transport,but also buffer the volume variations and maintain the structure integrity during Na+insertion/extraction,enabling its comparable fast reaction kinetics and cyclability with NC cathode.展开更多
The practicality of electrochemical water-splitting technology relies on the development of novel and efficient bifunctional electrocatalysts capable of facilitating both the hydrogen evolution reaction(HER)and oxygen...The practicality of electrochemical water-splitting technology relies on the development of novel and efficient bifunctional electrocatalysts capable of facilitating both the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).Black phosphorus(BP)holds tremendous promise for HER and OER electrocatalysis owing to its fully exposed atoms and high carrier mobility.However,the elec-trocatalytic performance of BP is still much lower than the expected theoretical limit,presenting an exciting challenge for further advancements.Herein,we embed electrochemically exfoliated few-layer BP nanosheets in higher Fermi level(EF)of cobalt,nitrogen co-doped carbons to form a new heterojunction(CoNC-BP),as efficient bifunctional electrocatalysts toward HER and OER for the advancement overall water splitting applications.A directed interfacial electron transfer is realized from CoNC to BP,facilitated by the lowering Fermi level(EF).This interfacial electron transfer plays a crucial role in optimizing the adsorption and desorption of active intermediates,while also introducing an abundance of hypervalent Co sites.These factors collectively contribute to the remarkable electrocatalytic activities of HER and OER performance,leading to the efficient performance of the developed CoNC-BP heterojunction in water-splitting applications.This work demonstrates a promising breakthrough that can inspire the design of high-efficiency catalysts.展开更多
The development of highly selective,cost-effective,and energy-efficient electrocatalysts is critical for carbon dioxide reduction reaction(CO_(2)RR)to produce high-value products.Herein,we propose a facile strategy to...The development of highly selective,cost-effective,and energy-efficient electrocatalysts is critical for carbon dioxide reduction reaction(CO_(2)RR)to produce high-value products.Herein,we propose a facile strategy to obtain F,N co-doped carbon-coated iron carbide(Fe3C)nanoparticles by using biomolecule guanine and hexadecafluorophthalocyanine iron as raw materials.Remarkably,this method involves only one-step pyrolysis and does not require any guiding agent or sacrificial template.Benefiting from the advantageous surface microenvironment adjustments achieved through graphitic N(GN)and F co-doping,Fe3C@NF-G-1000 demonstrates exceptional efficacy in the electroreduction of CO_(2)to carbon monoxide(CO)with an impressive Faradic efficiency(FEco)up to 98%at the potential of−0.55 V(vs.reversible hydrogen electrode(RHE)).Furthermore,it delivers a remarkable current density of up to−43 mA·cm^(−2)and exhibits virtually no current attenuation over a span of 20 h within the flow cell.Insights from density functional theory(DFT)calculations reveal that the composite structure of GN and F co-doped graphitic layer and Fe3C exhibits different electron density distributions from that of iron carbide nanoparticles.This is attributed to the synergistic effect of the composite structure leading to the enrichment of electrons in the graphite layer on the surface,which contributes to the stability of the key reaction intermediate*COOH,thus,resulting in an enhanced catalytic activity and efficiency.Overall,this work introduces a new and promising approach to the design of green and low-cost carbon-coated metal materials for CO_(2)reduction reactions.展开更多
Heteroatom doping has emerged as a prevailing strategy to enhance the storage of sodium ions in carbon materials.However,the underlying mechanism governing the performance enhancement remains undisclosed.Herein,we fab...Heteroatom doping has emerged as a prevailing strategy to enhance the storage of sodium ions in carbon materials.However,the underlying mechanism governing the performance enhancement remains undisclosed.Herein,we fabricated N/S co-doped carbon beaded fibers(S-N-CBFs),which exhibited glorious rate performance and durableness in Na+storage,showcasing no obvious capacity decay even after 3500 cycles.Furthermore,when used as anodes in sodium-ion capacitors,the S-N-CBFs delivered exceptional results,boasting a high energy density of 225 Wh·kg^(-1),superior power output of 22500 W·kg^(-1),and outstanding cycling stability with a capacity attenuation of merely 0.014%per cycle after 4000 cycles at 2 A·g^(-1).Mechanistic investigations revealed that the incorporation of both pyridinic N and pyrrolic N into the carbon matrix of S-N-CBFs induced internal electric fields(IEFs),with the former IEF being stronger than the latter,in conjunction with the doped S atom.Density functional theory calculations further unveiled that the intensity of the IEF directly influenced the adsorption of Na+,thereby resulting in the exceptional performances of S-N-CBFs as sodium-ion storage materials.This work uncovers the pivotal role of IEF in regulating the electronic structure of carbon materials and enhancing their Na^(+)storage capabilities,providing valuable insights for the development of more advanced electrode materials.展开更多
The selective oxidation of cyclohexane to cyclohexanone and cyclohexanol(KA oil)is a challenging issue in the chemical industry.At present the industrial conversion of cyclohexane to cyclohexanone and cyclohexanol is ...The selective oxidation of cyclohexane to cyclohexanone and cyclohexanol(KA oil)is a challenging issue in the chemical industry.At present the industrial conversion of cyclohexane to cyclohexanone and cyclohexanol is normally controlled at less than 5%selectivity.Thus,the development of highly active and stable catalysts for the aerobic oxidation of cyclohexane is necessary to overcome this low-efficiency process.Therefore,we have developed a cobalt-nitrogen co-doped porous sphere catalyst,Co-NC-x(x is the Zn/Co molar ratio,where x=0,0.5,1,2,and 4)by pyrolyzing resorcinol-formaldehyde resin microspheres.It achieved 88.28%cyclohexanone and cyclohexanol selectivity and a cyclohexane conversion of 8.88%under Co-NC-2.The results showed that the introduction of zinc effectively alleviated the aggregation of Co nanoparticles and optimized the structural properties of the material.In addition,Co0 and pyridinic-N are proposed to be the possible active species,and their proportion efficiently increased in the presence of Zn^(2+)species.In this study,we developed a novel strategy to design highly active catalysts for cyclohexane oxidation.展开更多
基金supported by the National Natural Science Foundation of China(No.52002320,and 51972267)the China Postdoctoral Science Foundation(No.2022M712574)+3 种基金the Science Foundation of Shaanxi Province(2022GD-TSLD-18,No.2023-JCZD-03)Natural Science Foundation of Shaanxi Province(No.2022GY-372,2021GY-153)Industrial Projects Foundation of Ankang Science and Technology Bureau(No.AK2020-GY02-2)the Platform Construction Projects and Technology Service Teams of Ankang University(No.2021AYPT12 and 2022TD07)。
文摘Sodium-ion batteries(SIBs) and hybrid capacitors(SIHCs) have garnered significant attention in energy storage due to their inherent advantages,including high energy density,cost-effectiveness,and enhanced safety.However,developing high-performance anode materials to improve sodium storage performa nce still remains a major challenge.Here,a facile one-pot method has been developed to fabricate a hybrid of MoSeTe nanosheets implanted within the N,F co-doped honeycomb carbon skeleton(MoSeTe/N,F@C).Experimental results demonstrate that the incorporation of large-sized Te atoms into MoSeTe nanosheets enlarges the layer spacing and creates abundant anion vacancies,which effectively facilitate the insertion/extraction of Na^(+) and provide numerous ion adsorption sites for rapid surface capacitive behavior.Additionally,the heteroatoms N,F co-doped honeycomb carbon skeleton with a highly conductive network can restrain the volume expansion and boost reaction kinetics within the electrode.As anticipated,the MoSeTe/N,F@C anode exhibits high reversible capacities along with exceptional cycle stability.When coupled with Na_(3)V_(2)(PO_(4))_(3)@C(NVPF@C) to form SIB full cells,the anode delivers a reversible specific capacity of 126 mA h g^(-1) after 100 cycles at 0.1 A g^(-1).Furthermore,when combined with AC to form SIHC full cells,the anode demonstrates excellent cycling stability with a reversible specific capacity of50 mA h g^(-1) keeping over 3700 cycles at 1.0 A g^(-1).In situ XRD,ex situ TEM characterization,and theoretical calculations(DFT) further confirm the reversibility of sodium storage in MoSeTe/N,F@C anode materials during electrochemical reactions,highlighting their potential for widespread practical application.This work provides new insights into the promising utilization of advanced transition metal dichalcogenides as anode materials for Na^(+)-based energy storage devices.
基金financially supported by the National Natural Science Foundation of China(Nos.51602018 and 51902018)the Natural Science Foundation of Beijing Municipality(No.2154052)+3 种基金the China Postdoctoral Science Foundation(No.2014M560044)the Fundamental Research Funds for the Central Universities(No.FRF-MP-20-22)USTB Research Center for International People-to-people Exchange in Science,Technology and Civilization(No.2022KFYB007)Education and Teaching Reform Foundation at University of Science and Technology Beijing(Nos.2023JGC027,KC2022QYW06,and KC2022TS09)。
文摘S and Co co-doped carbon catalysts were prepared via pyrolysis of MOF-71 and thiourea mixtures at 800℃at a mass ratio of MOF-71 to thiourea of 1:0.1 to effectively activate peroxymonosulfate(PMS)for methylene blue(MB)degradation.The effects of two different mixing routes were identified on the MB degradation performance.Particularly,the catalyst obtained by the alcohol solvent evaporation(MOF-AEP)mixing route could degrade 95.60%MB(50 mg/L)within 4 min(degradation rate:K=0.78 min^(-1)),which was faster than that derived from the direct grinding method(MOF-DGP,80.97%,K=0.39 min^(-1)).X-ray photoelectron spectroscopy revealed that the Co-S content of MOF-AEP(43.39at%)was less than that of MOF-DGP(54.73at%),and the proportion of C-S-C in MOF-AEP(13.56at%)was higher than that of MOF-DGP(10.67at%).Density functional theory calculations revealed that the adsorption energy of Co for PMS was -2.94 eV when sulfur was doped as C-S-C on the carbon skeleton,which was higher than that when sulfur was doped next to cobalt in the form of Co-S bond(-2.86 eV).Thus,the C-S-C sites might provide more contributions to activate PMS compared with Co-S.Furthermore,the degradation parameters,including pH and MOF-AEP dosage,were investigated.Finally,radical quenching experiments and electron paramagnetic resonance(EPR)measurements revealed that ^(1)O_(2)might be the primary catalytic species,whereas·O~(2-)might be the secondary one in degrading MB.
基金Collaborative Innovation Center of Suzhou Nano Science and TechnologyNational Natural Science Foundation of China,Grant/Award Numbers:21773163,22271203+3 种基金EPSRC for an Overseas Travel Grant,Grant/Award Number:EP/R023816/1State Key Laboratory of Organometallic Chemistry of Shanghai Institute of Organic Chemistry,Grant/Award Number:KF2021005Priority Academic Program Development of Jiangsu Higher Education InstitutionsProject of Scientific and Technologic Infrastructure of Suzhou,Grant/Award Number:SZS201905。
文摘The development of simple and effective strategies to prepare electrocatalysts,which possess unique and stable structures comprised of metal/nonmetallic atoms for oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),is currently an urgent issue.Herein,an efficient bifunctional electrocatalyst featured by ultralong N,S-doped carbon nano-hollow-sphere chains about 1300 nm with encapsulated Co nanoparticles(Co-CNHSCs)is developed.The multifunctional catalytic properties of Co together with the heteroatom-induced charge redistribution(i.e.,modulating the electronic structure of the active site)result in superior catalytic activities toward OER and ORR in alkaline media.The optimized catalyst Co-CNHSC-3 displays an outstanding electrocatalytic ability for ORR and OER,a high specific capacity of 1023.6 mAh gZn^(-1),and excellent reversibility after 80 h at 10mA cm^(-2)in a Zn-air battery system.This work presents a new strategy for the design and synthesis of efficient multifunctional carbon-based catalysts for energy storage and conversion devices.
基金financially supported by the Shenzhen Science and Technology Program(JCYJ20220530141012028),ChinaThe National Natural Science Foundation of China(22005178),China+2 种基金The Key Research and Development Program of Shandong Province(2021ZLGX01),ChianThe fellowship of China Postdoctoral Science Foundation(2022M722333),Chianthe Jiangsu Funding Program for Excellent Postdoctoral Talent,Chian。
文摘Hollow nanostructures with external shells and inner voids have been proved to greatly shorten the transport distance of ions/electrons and buffer volume change,especially for the large-sized potassium-ions in secondary batteries.In this work,hollow carbon(HC) nanospheres embedded with S,P co-doped NiSe_(2)nanoparticles are fabricated by "drop and dry" and "dissolving and precipitation" processes to form Ni(OH)2nanocrystals followed by annealing with S and P dopants to form nanoparticles.The resultant S,P-NiSe_(2)/HC composite exhibits excellent cyclic performance with 131.6 mA h g^(-1)at1000 mA g^(-1)after 3000 cycles for K^(+)storage and a capacity of 417.1 mA h g^(-1)at 1000 mA g^(-1)after1000 cycles for Li^(+)storage.K-ion full cells are assembled and deliver superior cycling stability with a ca pacity of 72.5 mA h g^(-1)at 200 mA g^(-1)after 500 cycles.The hollow carbon shell with excellent electrical conductivity effectively promotes the transporta tion and tolerates large volume variation for both K^(+)and Li^(+).Density functional theory calculations confirm that the S and P co-doping NiSe_(2) enables stronger adsorption of K^(+)ions and higher electrical conductivity that contributes to the improved electrochemical performance.
基金supported by the National Key R&D Program of China(2021YFC2103704)the National Natural Science Foundation of China(22022812,21978259)+1 种基金Key R&D Program of Zhejiang(2022C01208)Institute of Zhejiang University-Quzhou S&T Planed Projects(IZQ2021KJ1001)。
文摘Hydrodeoxygenation of furfural(FF)into 2-methylfuran(MF)is a significant biomass utilization route.However,designing efficient and stable non-noble metal catalyst is still a huge challenge.Herein,we reported the N,O co-doped carbon anchored with Co nanoparticles(Co-SFB)synthesized by employing the organic ligands with the target heteroatoms.Raman,electron paramagnetic resonance(EPR),electrochemical impedance spectroscopy(EIS),and X-ray photoelectron spectroscopy(XPS)characterizations showed that the co-doping of N and O heteroatoms in the carbon support endows Co-SFB with enriched lone pair electrons,fast electron transfer ability,and strong metal-support interaction.These electronic properties resulted in strong FF adsorption as well as lower apparent reaction activation energy.At last,the obtained N,O co-doped Co/C catalyst showed excellent catalytic activity(nearly 100 mol%FF conversion and 94.6 mol%MF yield)and stability for in-situ dehydrogenation of FF into MF.This N,O co-doping strategy for the synthesis of highly efficient catalytic materials with controllable electronic state will provide an excellent opportunity to better understand the structure-function relationship.
基金financial support from the National Natural Science Foundation of China (Nos. 21476089, 21373091)the Provincial Science and Technology Project of Guangdong (No. 2014A030312007)
文摘Renewable lignin used for synthesizing materials has been proven to be highly potential in specific electrochemistry.Here,we report a simple method to synthesize nitrogen and sulfur co-doped carbon nanosheets by using bagasse lignin,denoted as lignin-derived carbon(LC).By adjusting the ratio of nitrogen source and annealing temperature,we obtained the ultrathin graphitic lignin carbon(LC-4-1000)with abundant wrinkles with high surface area of 1208 m2g_1 and large pore volume of 1.40 cm3g_1.In alkaline medium,LC-4-1000 has more positive half-wave potential and nearly current density compared to commercial Pt/C for oxygen reduction reaction(ORR).More importantly,LC-4-1000 also exhibits comparable activity and superior stability for ORR in acid medium due to its high graphitic N ratio and a direct four electron pathway for ORR.This study develops a cost-effective and highly efficient method to prepare biocarbon catalyst for ORR in fuel cells.
基金financial support from the National Natural Science Foundation of China (21773111, 21473089, 21573107 and 51571110)the National Key Research and Development Program of China (2017YFA0206503, 2018YFA0209103)+1 种基金Priority Academic Program Development of Jiangsu Higher Education Institutions, Fundamental Research Funds for the Central Universitiesthe program B for outstanding PhD candidate of Nanjing University (201702B049)
文摘Exploring inexpensive and efficient bifunctional electrocatalysts for oxygen reduction reaction(ORR) and oxygen evolution reaction(OER) is critical for rechargeable metal-air batteries. Herein, we report a new 3D hierarchical sulfur and nitrogen co-doped carbon nanocages(hSNCNC) as a promising bifunctional oxygen electrocatalyst by an in-situ MgO template method with pyridine and thiophene as the mixed precursor. The as-prepared h SNCNC exhibits a positive half-wave potential of 0.792 V(vs. reversible hydrogen electrode, RHE) for ORR, and a low operating potential of 1.640 V at a 10 mA cm-2 current density for OER. The reversible oxygen electrode index is 0.847 V, far superior to commercial Pt/C and IrO2,which reaches the top level of the reported bifunctional catalysts. Consequently, the hSNCNC as air cathodes in an assembled Zn-air battery features low charge/discharge overpotential and long lifetime. The remarkable properties arises from the introduced multiple heteroatom dopants and stable 3D hierarchical structure with multi-scale pores, which provides the abundant uniform high-active S and N species and efficient charge transfer as well as mass transportation. These results demonstrate the potential strategy in developing suitable carbon-based bi-/multi-functional catalysts to enable the next generation of the rechargeable metal-air batteries.
基金supported by the National Natural Science Foundation of China(52374301 and 22279030)the Fundamental Research Funds for the Central Universities(N2223037)+1 种基金Hebei Key Laboratory of Dielectric and Electrolyte Functional Material,Northeastern University at Qinhuangdao(HKDEFM2021201)the Performance subsidy fund for the Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province(22567627H)。
文摘The interface mechanism between catalyst and carbon substrate has been the focus of research.In this paper,the FeCo alloy embedded N,S co-doped carbon substrate bifunctional catalyst(FeCo/S-NC)is obtained by a simple one-step pyrolysis strategy.The experimental results and density functional theory(DFT)calculation show that the formation of FeCo alloy is conducive to promoting electron transfer,and the introduction of S atom can enhance the interaction between FeCo alloy and carbon substrate,thus inhibiting the migration and agglomeration of particles on the surface of carbon material.The FeCo/SNC catalysts show outstanding performance for oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).FeCo/S-NC shows a high half-wave potential(E_(1/2)=0.8823 V)for ORR and a low overpotential at 10 mA cm^(-2)(E_(j=10)=299 mV)for OER.In addition,compared with Pt/C+RuO_(2) assembled Zn-air battery(ZAB),the FeCo/S-NC assembled ZAB exhibits a larger power density(198.8 mW cm^(-2)),a higher specific capacity(786.1 mA h g_(zn)~(-1)),and ultra-stable cycle performance.These results confirm that the optimized composition and the interfacial interaction between catalyst and carbon substrate synergistically enhance the electrochemical performance.
基金Project supported by the National Natural Science Foundation of China(Grant No.21276045)
文摘Oxidized asphaltene (OA), a thermosetting material with plenty of functional groups, is synthesized from asphaltene (A) using HNO3]HzSO4 as the oxidizing agent. Boron, nitrogen co-doped porous carbon (BNC-OA) is prepared by carbonization of the mixture of boric acid and OA at 1173 K in an argon atmosphere. X-ray photoelectron spectroscopy (XPS) characterization reveals that the BNC-OA has a nitrogen content of 3.26 at.% and a boron content of 1.31 at.%, while its oxidation-free counterpart (BNC-SA) has a nitrogen content of 1.61 at.% and a boron content of 3.02 at.%. The specific surface area and total pore volume of BNC-OA are 1103 m2·g^-1 and 0.921 cm3·g^-1, respectively. At a current density of 0.1 A·g^-1, the specific capacitance of BNC-OA is 335 F·g^-1 and the capacitance retention can still reach 83% at 1 A·g^-1. The analysis shows that the superior electrochemical performance of the BNC-OA is attributed to the pseudocapacitance behavior of surface heteroatom functional groups and an abundant pore-structure. Boron, nitrogen co-doped porous carbon is a promising electrode material for supercapacitors.
基金supported by Joint Funds of the National Natural Science Foundation of China(U20A20280)the National Natural Science Foundation of China(21805083,52074119)+3 种基金the Academy of Sciences large apparatus United Fund of China(U1832187)the Scientific Research Fund of Hunan Provincial Education Department(19K058)the Science and Technology Planning Project of Hunan Province(2018TP1017)the High-Tech Leading Plan of Hunan Province(2020GK2072).
文摘Silicon-based(Si)materials are promising anodes for lithium-ion batteries(LIBs)because of their ultrahigh theoretical capacity of 4200 mA h g^(−1).However,commercial applications of Si anodes have been hindered by their drastic volume variation(∼300%)and low electrical conductivity.Here,to tackle the drawbacks,a hierarchical Si anode with double-layer coatings of a SiOx inner layer and a nitrogen(N),boron(B)co-doped carbon(C-NB)outer layer is elaborately designed by copyrolysis of Si-OH structures and a H3BO_(3)-doped polyaniline polymer on the Si surface.Compared with the pristine Si anodes(7mA h g^(−1) at 0.5 A g^(−1) after 340 cycles and 340 mA h g^(−1) at 5 A g^(−1)),the modified Si-based materials(Si@SiOx@C-NB nanospheres)present su perior cycling stability(reversible 1301 mA h g^(−1) at 0.5 A g^(−1) after 340 cycles)as well as excellent rate capability(690mA h g^(−1) at 5 A g^(−1))when used as anodes in LIBs.The unique double-layer coating structure,in which the inner amorphous SiOx layer acts as a buffer matrix and the outer defect-rich carbon enhances the electron diffusion of the whole anode,makes it possible to de liver excellent electrochemical properties.These results indicate that our double-layer coating strategy is a promising approach not only for the devel opment of sustainable Si anodes but also for the design of multielement-doped carbon nanomaterials.
基金We gratefully acknowledge financial supports from the National Natural Science Foundation of China(No.52202371,51905125,52102364)the Natural Science Foundation of Shandong Province(No.ZR2020QE066)+2 种基金Opening Project of State Key Laboratory of Advanced Technology for Float Glass(No.2020KF08)SDUT&Zibo City Integration Development Project(No.2021SNPT0045)the fellowship of China Postdoctoral Science Foundation(No.2020M672081).
文摘Biomass-derived carbon has demonstrated great potentials as advanced electrode for capacitive deionization(CDI),owing to good electroconductivity,easy availability,intrinsic pores/channels.However,conventional simple pyrolysis of biomass always generates inadequate porosity with limited surface area.Moreover,biomass-derived carbon also suffers from poor wettability and single physical adsorption of ions,resulting in limited desalination performance.Herein,pore structure optimization and element co-doping are integrated on banana peels(BP)-derived carbon to construct hierarchically porous and B,N co-doped carbon with large ions-accessible surface area.A unique expansionactivation(EA)strategy is proposed to modulate the porosity and specific surface area of carbon.Furthermore,B,N co-doping could increase the ions-accessible sites with improved hydrophilicity,and promote ions adsorption.Benefitting from the synergistic effect of hierarchical porosity and B,N co-doping,the resultant electrode manifest enhanced CDI performance for NaCl with large desalination capacity(29.5 mg g^(-1)),high salt adsorption rate(6.2 mg g^(-1)min^(-1)),and versatile adsorption ability for other salts.Density functional theory reveals the enhanced deionization mechanism by pore and B,N co-doping.This work proposes a facile EA strategy for pore structure modulation of biomass-derived carbon,and demonstrates great potentials of integrating pore and heteroatoms-doping on constructing high-performance CDI electrode.
基金the National Natural Science Foundation of China(U1710122,51862035 and 21773293)the Science and Technology Project of Jiangxi Province(20181ACH80008,20181ACE50012,20192BCD40017 and 20192ACB80002)+1 种基金Jiangxi Double Thousand Talent Program(S2018LQCQ0016)Suzhou Science and Technology Plan Projects(SYG201831)。
文摘Developing high power and energy supercapacitors(SCs)is a long-pursued goal for the application in transportation and energy storage station.Herein,a rationally-designed Co-doped nickel oxide nanosheets@carbon-welded carbon nanotube foam(Co-doped NiO@WCNTF)as freestanding electrode is successfully prepared for high power and energy SCs.The WCNTF framework with high specific surface area provides three dimensional highly conductive network for fast charge transport and ensures high loading of active materials(9.2 mg/cm2).Moreover,porous Co-doped NiO nanosheets uniformly anchored on the WCNTF framework enable rapid charge kinetics due to the high intrinsic conductivity of Co-doped Ni O nanosheets and their good contact with conductive WCNTF substrate.As a result,the unique integrated electrode with 3D architecture exhibits an ultrahigh specific capacitance of 11.45 F/cm2 at 5 mA/cm2,outstanding rate capability(11.45 F/cm2 at 5 mA/cm2 and a capacitance retention of 86.2%at 30 mA/cm2)and good cycling stability,suggesting great potential for high performance supercapacitor.
基金supported by Natural Science Foundation of China(NSFC)(Grant No.91333112U1432249)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutionssupported by Collaborative Innovation Center of Suzhou Nano Science&Technology and sponsored by Qing Lan Project
文摘Direct synthesis of high-quality doped graphene on dielectric substrates without transfer is highly desired for simplified device processing in electronic applications.However,graphene synthesis directly on substrates suitable for device applications,though highly demanded,remains unattainable and challenging.Here,a simple and transfer-free synthesis of high-quality doped graphene on the dielectric substrate has been developed using a thin Cu layer as the top catalyst and polycyclic aromatic hydrocarbons as both carbon precursors and doping sources.N-doped and N,F-co-doped graphene have been achieved using TPB and F16Cu Pc as solid carbon sources,respectively.The growth conditions were systematically optimized and the as-grown doped graphene were well characterized.The growth strategy provides a controllable transfer-free route for high-quality doped graphene synthesis,which will facilitate the practical applications of graphene.
基金financially supported by the National Natural Science Foundation of China(51702225,51672181,52071225)the National Key R&D Program of China(2019YFA0708201)+3 种基金the China Post-doctoral Foundation(7131705619)the Czech Republic from ERDF“Institute of Environmental Technology-Excel ent Research”(No.CZ.02.1.01/0.0/0.0/16_019/0000853)the Sino-German Research Institute for support(project:GZ 1400)the support from Suzhou Key Laboratory for Advanced Carbon Materials and Wearable Energy Technologies,Suzhou,China。
文摘Among various anode candidates for potassium-ion batteries,carbonaceous materials have attracted significant attention due to their overwhelming advantages including cost-effectiveness and environmental benignity.However,the inferior specific capacity and the sluggish reaction kinetics hinder the further development in this realm.Herein,we report biomass templated synthesis of boron/oxygen heteroatom co-doped carbon particles(BO-CPs)via direct plasma-enhanced chemical vapor deposition.With the combined advantages of abundant active sites,large accessible surface area,and functional groups,BO-CP anode exhibits high reversible specific capacity(426.5 mAh g^(-1)at 0.1 A g^(-1))and excellent rate performance(166.5 mAh g^(-1)at 5 A g^(-1)).The K-ion storage mechanism is probed by operando Raman spectroscopy,ex situ X-ray photoelectron spectroscopy/electrochemical impedance spectroscopy,galvanostatic intermittent titration technique measurements,and theoretical simulations.The synergistic effect of boron and oxygen co-doping greatly facilitates the performance of carbon-based anode,wherein boron dopant improves the conductivity of carbon framework and the oxygen dopant affords ample active sites and thus harvests additional specific capacity.This work is anticipated to propel the development of high-performance anode materials for emerging energy storage devices.
基金supported by the National Natural Science Foundation of China(Grant No.21975148,21601118,21773146,21902099,and 21905167)the Fundamental Research Funds for the Central Universities(GK201903033 and GK202003025)+5 种基金the “Thousand Talents Program”of Chinathe Fok Ying-Tong Education Foundation for Outstanding Young Teachers in Universitythe China Postdoctoral Science Foundation(2019M650254,and 2020T130391)the Opening Fund of State Key Laboratory of Heavy Oil Processing(SKLOP202002005)the Research Fund Program of Key Laboratory of Fuel Cell Technology of Guangdong Provincethe Research Funds of Shaanxi Normal University。
文摘Oxygen reduction reaction (ORR) is an important process for the conversion and utilization of a wide range of renewable energy sources, and is critical for the shape of future energy scenario [1–10]. However, ORR is a complex four-electron transfer process and is kinetically sluggish. It is urgent to develop high-efficient electrocatalysts to solve this problem [11–15]. Up to now, precious metal-based catalysts such as Pt-based electrocatalysts have been widely studied and found to be one of the most efficient electrocatalysts for ORR. However, the high price and the small reserves limit their large-scale commercialization [10,16–23]. Therefore, in order to fulfill needs for the practical applications, it is necessary to develop low-cost electrocatalysts, also with high activity and great stability [19,24–28].
基金financially supported by the NRF Investigatorship (NRFI), Award No. NRF-NRFI2016-05the Campus for Research Excellent and Technological Enterprise (CREATE),National Research Foundation, Prime Minister’s Office, Singapore
文摘Sodium-ion capacitors(SICs)have received increasing interest for grid stationary energy storage application due to their affordability,high power,and energy densities.The major challenge for SICs is to overcome the kinetics imbalance between faradaic anode and nonfaradaic cathode.To boost the Na+reaction kinetics,the present work demonstrated a high-rate MnS-based anode by embedding the MnS nanocrystals into the N,S-co-doped carbon matrix(MnS@NSC).Benefiting from the fast pseudocapacitive Na+storage behavior,the resulting composite exhibits extraordinary rate capability(205.6 mAh g−1 at 10 A g−1)and outstanding cycling stability without notable degradation after 2000 cycles.A prototype SIC was demonstrated using MnS@NSC anode and N-doped porous carbon(NC)cathode;the obtained hybrid SIC device can display a high energy density of 139.8 Wh kg−1 and high power density of 11,500 W kg−1,as well as excellent cyclability with 84.5%capacitance retention after 3000 cycles.The superior electrochemical performance is contributed to downsizing of MnS and encapsulation of conductive N,S-co-doped carbon matrix,which not only promote the Na+and electrons transport,but also buffer the volume variations and maintain the structure integrity during Na+insertion/extraction,enabling its comparable fast reaction kinetics and cyclability with NC cathode.
基金National Natural Science Foundation of China(Grant No.62004143)Key R&D Program of Hubei Province(Grant No.2022BAA084)+4 种基金Natural Science Foundation of Hubei Province(Grant No.2021CFB133)National Key R&D Program of China(Grant No.2022YFC3902703)Innovation Project of Engineering Research Center of Phosphorus Resources Development and Utilization of Ministry of Education(Grant No.LCX2021003)Open Research Fund of Key Laboratory of Material Chemistry for Energy Conversion and Storage(HUST),Ministry of Education(Grant No.2021JYBKF05)14th Graduate Ed-ucation Innovation Fund of Wuhan Institute of Technology(Grant Nos.CX2022564 and CX2022451).
文摘The practicality of electrochemical water-splitting technology relies on the development of novel and efficient bifunctional electrocatalysts capable of facilitating both the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).Black phosphorus(BP)holds tremendous promise for HER and OER electrocatalysis owing to its fully exposed atoms and high carrier mobility.However,the elec-trocatalytic performance of BP is still much lower than the expected theoretical limit,presenting an exciting challenge for further advancements.Herein,we embed electrochemically exfoliated few-layer BP nanosheets in higher Fermi level(EF)of cobalt,nitrogen co-doped carbons to form a new heterojunction(CoNC-BP),as efficient bifunctional electrocatalysts toward HER and OER for the advancement overall water splitting applications.A directed interfacial electron transfer is realized from CoNC to BP,facilitated by the lowering Fermi level(EF).This interfacial electron transfer plays a crucial role in optimizing the adsorption and desorption of active intermediates,while also introducing an abundance of hypervalent Co sites.These factors collectively contribute to the remarkable electrocatalytic activities of HER and OER performance,leading to the efficient performance of the developed CoNC-BP heterojunction in water-splitting applications.This work demonstrates a promising breakthrough that can inspire the design of high-efficiency catalysts.
基金the financial support from the National Natural Science Foundation of China(Nos.22072018 and 22372039)the Natural Science Foundation of Fujian Province of China(No.2021J06010).
文摘The development of highly selective,cost-effective,and energy-efficient electrocatalysts is critical for carbon dioxide reduction reaction(CO_(2)RR)to produce high-value products.Herein,we propose a facile strategy to obtain F,N co-doped carbon-coated iron carbide(Fe3C)nanoparticles by using biomolecule guanine and hexadecafluorophthalocyanine iron as raw materials.Remarkably,this method involves only one-step pyrolysis and does not require any guiding agent or sacrificial template.Benefiting from the advantageous surface microenvironment adjustments achieved through graphitic N(GN)and F co-doping,Fe3C@NF-G-1000 demonstrates exceptional efficacy in the electroreduction of CO_(2)to carbon monoxide(CO)with an impressive Faradic efficiency(FEco)up to 98%at the potential of−0.55 V(vs.reversible hydrogen electrode(RHE)).Furthermore,it delivers a remarkable current density of up to−43 mA·cm^(−2)and exhibits virtually no current attenuation over a span of 20 h within the flow cell.Insights from density functional theory(DFT)calculations reveal that the composite structure of GN and F co-doped graphitic layer and Fe3C exhibits different electron density distributions from that of iron carbide nanoparticles.This is attributed to the synergistic effect of the composite structure leading to the enrichment of electrons in the graphite layer on the surface,which contributes to the stability of the key reaction intermediate*COOH,thus,resulting in an enhanced catalytic activity and efficiency.Overall,this work introduces a new and promising approach to the design of green and low-cost carbon-coated metal materials for CO_(2)reduction reactions.
基金the National Natural Science Foundation of China(No.22138013).
文摘Heteroatom doping has emerged as a prevailing strategy to enhance the storage of sodium ions in carbon materials.However,the underlying mechanism governing the performance enhancement remains undisclosed.Herein,we fabricated N/S co-doped carbon beaded fibers(S-N-CBFs),which exhibited glorious rate performance and durableness in Na+storage,showcasing no obvious capacity decay even after 3500 cycles.Furthermore,when used as anodes in sodium-ion capacitors,the S-N-CBFs delivered exceptional results,boasting a high energy density of 225 Wh·kg^(-1),superior power output of 22500 W·kg^(-1),and outstanding cycling stability with a capacity attenuation of merely 0.014%per cycle after 4000 cycles at 2 A·g^(-1).Mechanistic investigations revealed that the incorporation of both pyridinic N and pyrrolic N into the carbon matrix of S-N-CBFs induced internal electric fields(IEFs),with the former IEF being stronger than the latter,in conjunction with the doped S atom.Density functional theory calculations further unveiled that the intensity of the IEF directly influenced the adsorption of Na+,thereby resulting in the exceptional performances of S-N-CBFs as sodium-ion storage materials.This work uncovers the pivotal role of IEF in regulating the electronic structure of carbon materials and enhancing their Na^(+)storage capabilities,providing valuable insights for the development of more advanced electrode materials.
基金supported by National Natural Science Foundation of China(Grant No.22178294)Science and Technology Innovation Program of Hunan Province(Grant No.2022RC1117)+2 种基金Project of Hunan Provincial Education Department(Grant No.22A0125)Hunan Provincial Natural Science Foundation of China(Grant No.2021JJ30663)Postgraduates Scientific Research Innovation Project of Xiangtan University(Grant No.QL20220146)。
文摘The selective oxidation of cyclohexane to cyclohexanone and cyclohexanol(KA oil)is a challenging issue in the chemical industry.At present the industrial conversion of cyclohexane to cyclohexanone and cyclohexanol is normally controlled at less than 5%selectivity.Thus,the development of highly active and stable catalysts for the aerobic oxidation of cyclohexane is necessary to overcome this low-efficiency process.Therefore,we have developed a cobalt-nitrogen co-doped porous sphere catalyst,Co-NC-x(x is the Zn/Co molar ratio,where x=0,0.5,1,2,and 4)by pyrolyzing resorcinol-formaldehyde resin microspheres.It achieved 88.28%cyclohexanone and cyclohexanol selectivity and a cyclohexane conversion of 8.88%under Co-NC-2.The results showed that the introduction of zinc effectively alleviated the aggregation of Co nanoparticles and optimized the structural properties of the material.In addition,Co0 and pyridinic-N are proposed to be the possible active species,and their proportion efficiently increased in the presence of Zn^(2+)species.In this study,we developed a novel strategy to design highly active catalysts for cyclohexane oxidation.