Two-dimensional(2D)oxides have been the focus of substantial research interest recently,owing to their fascinating physico-chemical properties.However,fabrication of large-area 2D oxide materials in a controlled manne...Two-dimensional(2D)oxides have been the focus of substantial research interest recently,owing to their fascinating physico-chemical properties.However,fabrication of large-area 2D oxide materials in a controlled manner under mild conditions still remains a formidable challenge.Herein,we develop a facile and universal strategy based on the sonochemistry approach for controllable and large-area growth of quasi-aligned single-crystalline ZnO nanosheets on a Zn substrate(Zn@SC-ZnO)under ambient conditions.The obtained ZnO nanosheets possess the desired exclusively exposed(001)facets,which have been confirmed to play a critical role in significantly reducing the activation energy and facilitating the stripping/plating processes of Zn.Accordingly,the constructed Zn@SC-ZnO||Zn@SC-ZnO symmetric cell has very low polarization overpotential down to~20 mV,with limited dendrite growth and side reactions for Zn anodes.The developed Zn@SC-ZnO//MnO_(2)aqueous Zn-ion batteries(ZIBs)show a voltage efficiency of 88.2%under 500 mA g^(-1)at the stage of 50%depth of discharge,which is state of the art for ZIBs reported to date.Furthermore,the as-assembled large-size cell(5 cm×5 cm)delivers an open circuit potential of 1.648 V,and can be robustly operated under a high current of 20 mA,showing excellent potential for future scalable applications.展开更多
FeS_(2)cathode is promising for all-solid-state lithium batteries due to its ultra-high capacity,low cost,and environmental friendliness.However,the poor performances,induced by limited electrode-electrolyte interface...FeS_(2)cathode is promising for all-solid-state lithium batteries due to its ultra-high capacity,low cost,and environmental friendliness.However,the poor performances,induced by limited electrode-electrolyte interface,severe volume expansion,and polysulfide shuttle,hinder the application of FeS_(2)in all-solid-state lithium batteries.Herein,an integrated 3D FeS_(2)electrode with full infiltration of Li6PS5Cl sulfide electrolytes is designed to address these challenges.Such a 3D integrated design not only achieves intimate and maximized interfacial contact between electrode and sulfide electrolytes,but also effectively buffers the inner volume change of FeS_(2)and completely eliminates the polysulfide shuttle through direct solid-solid conversion of Li2S/S.Besides,the vertical 3D arrays guarantee direct electron transport channels and horizontally shortened ion diffusion paths,endowing the integrated electrode with a remarkably reduced interfacial impedance and enhanced reaction kinetics.Benefiting from these synergies,the integrated all-solid-state lithium battery exhibits the largest reversible capacity(667 mAh g^(-1)),best rate performance,and highest capacity retention of 82%over 500 cycles at 0.1 C compared to both a liquid battery and non-integrated all-solid-state lithium battery.The cycling performance is among the best reported for FeS_(2)-based all-solid-state lithium batteries.This work presents an innovative synergistic strategy for designing long-cycling high-energy all-solid-state lithium batteries,which can be readily applied to other battery systems,such as lithium-sulfur batteries.展开更多
Photoanodes based on In_2S_3/ZnO heterojunction nanosheet arrays(NSAs) have been fabricated by atomic layer deposition of ZnO over In_2S_3 NSAs, which were in situ grown on fluorine-doped tin oxide glasses via a facil...Photoanodes based on In_2S_3/ZnO heterojunction nanosheet arrays(NSAs) have been fabricated by atomic layer deposition of ZnO over In_2S_3 NSAs, which were in situ grown on fluorine-doped tin oxide glasses via a facile solvothermal process. The as-prepared photoanodes show dramatically enhanced performance for photoelectrochemical(PEC) water splitting, compared to single semiconductor counterparts. The optical and PEC properties of In_2S_3/ZnO NSAs have been optimized by modulating the thickness of the Zn O overlayer. After pairing with ZnO, the NSAs exhibit a broadened absorption range and an increased light absorptance over a wide wavelength region of 250–850 nm. The optimized sample of In_2S_3/ZnO-50 NSAs shows a photocurrent density of 1.642 m A cm^(-2)(1.5 V vs. RHE) and an incident photonto-current efficiency of 27.64% at 380 nm(1.23 V vs.RHE), which are 70 and 116 times higher than those of the pristine In_2S_3 NSAs, respectively. A detailed energy band edge analysis reveals the type-II band alignment of the In_2S_3/ZnO heterojunction, which enables efficient separation and collection of photogenerated carriers,especially with the assistance of positive bias potential, and then results in the significantly increased PEC activity.展开更多
Sodium metal battery(SMB)is regarded as a promising candidate for next-generation high-energy battery due to high theoretical capacity and abundant natural resources.However,the growth of sodium dendrites and large vo...Sodium metal battery(SMB)is regarded as a promising candidate for next-generation high-energy battery due to high theoretical capacity and abundant natural resources.However,the growth of sodium dendrites and large volume expansion during the processes of sodium plating and stripping seriously restrict the practical application of SMBs.Here,a three-dimensional skeleton of aluminum nanosheet arrays(Al NSARs)is constructed by a facile etching approach to achieve rapid and reversible Na plating/stripping.The Al NSARs with large geometric specific surface and plentiful cavities can provide rich active nucleation sites,reduce local current density and accommodate Na volume change,which lead to uniform deposition of sodium with dendrite-free morphology.As a result,Na plating/stripping on Al NSARs can stably operate over 650 cycles at 2 mA cm^(-2)/2 mAh cm^(-2)with average Coulombic efficiency(CE)of 100.0%and low potential polarization of 27 mV.Moreover,the full cell of Na_(s)V_(2)(PO_(4))_(3)||Al NSARs@Na can run for over 1800 cycles at a high rate of 20C.These superior properties,combined with relatively low cost and weight of Al,enable our AlNSARs to begreat prospect for practical applications.展开更多
Modulate the electronic structure and surface energy by nanostructure and heteroatom doping is an efficient strategy to improve electrocatalytic activity of hydrogen evolution reaction(HER).Herein,nickel incorporated ...Modulate the electronic structure and surface energy by nanostructure and heteroatom doping is an efficient strategy to improve electrocatalytic activity of hydrogen evolution reaction(HER).Herein,nickel incorporated WP_(2) self-supporting nanosheet arrays cathode was synthesized on carbon cloth(Ni-WP_(2) NS/CC)by in-situ phosphating reduction of the Ni-doped WO3.It shows that heteroatom doping and the three-dimensional(3D)nanosheet arrays morphology both facilitate to reduce the interfacial transfer resistance and increase electrochemical-active surface areas,which effectively improve electrocatalytic hydrogen evolution reaction(HER)activity.The optimized catalyst,1%Ni-WP_(2) NS/CC,exhibits an outstanding electrocatalytic performance with an overpotential of 110 m V at 10 m A cm^(-2) and a Tafel slope of 65 m V dec^(-1) in the acid solution.DFT calculations further demonstrate the nickel doping can adjust the intrinsic structure of electronics,lower the Gibbs free energy of adsorption of hydrogen(DGH*),and effectively improve the HER performance.展开更多
One-dimensional(1D, wire-and fiber-shaped)supercapacitors have recently attracted interest due to their roll-up, micrometer size and potential applications in portable or wearable electronics. Herein, a 1D wireshaped ...One-dimensional(1D, wire-and fiber-shaped)supercapacitors have recently attracted interest due to their roll-up, micrometer size and potential applications in portable or wearable electronics. Herein, a 1D wireshaped electrode was developed based on Fe_3O_4 nanosheet arrays connected on the Fe wire, which was prepared via oxidation of Fe wire in 0.1 M KCl solution(pH 3) with O2-rich environment under 70 °C. The obtained Fe_3O_4 nanosheet arrays displayed a high specific capacitance(20.8 m F cm^(-1) at 10 mV s^(-1)) and long cycling lifespan(91.7% retention after 2500 cycles). Theexcellent performance may attribute to the connected nanosheet structure with abundant open spaces and the intimate contact between the Fe_3O_4 and iron substrate. In addition, a wire-shaped asymmetric supercapacitor was fabricated and had excellent capacitive properties with a high energy density(9 l Wh cm^(-2)) at power density of 532.7 l W cm^(-2) and remarkable long-term cycling performance(99% capacitance retention after 2000 cycles).Considering low cost and earth-abundant electrode material, as well as outstanding electrochemical properties, the assembled supercapacitor will possess enormous potential for practical applications in portable electronic device.展开更多
Selective CO_(2)-to-CO photoreduction is under intensive research and requires photocatalysts with tuned microstructures to accelerate the reaction kinetics.Here,we report CuInS_(2)nanosheet arrays with sulfur vacanci...Selective CO_(2)-to-CO photoreduction is under intensive research and requires photocatalysts with tuned microstructures to accelerate the reaction kinetics.Here,we report CuInS_(2)nanosheet arrays with sulfur vacancies(VS)grown on the two-dimensional(2D)support of Ti_(3)C_(2)T_(x)MXene for CO_(2)-to-CO photoreduction.Our results reveal that the use of Ti_(3)C_(2)T_(x)induces strong support effect,which causes the hierarchical nanosheet arrays growth of CuInS_(2)and simultaneously leads to charge transfer from CuInS_(2)to Ti_(3)C_(2)T_(x)support,resulting in VSformed in CuInS_(2).The strong support effect based on Ti_(3)C_(2)T_(x)is proven to be applicable to prepare a series of different metal indium sulfide arrays with VS.CuInS_(2)nanosheet arrays with VSsupported on Ti_(3)C_(2)T_(x)benefit the photocatalytic selective reduction of CO_(2)to CO,manifesting a remarkable over 14.8-fold activity enhancement compared with pure CuInS_(2).The experimental and computational investigations pinpoint that VSof CuInS_(2)resulting from the support effect of Ti_(3)C_(2)T_(x)lowers the barrier of the rate-limiting step of^(*)COOH→^(*)OH+^(*)CO,which is the key to the photoactivity enhancement.This work demonstrates MXene support effects and offers an effective approach to regulate the atomic microstructure of metal sulfides toward enhancing photocatalytic performance.展开更多
The problems of electromagnetic wave(EMW)pollution in X and Ku bands(8–18 GHz)are becoming more and more serious.Therefore,it is urgent to design EMW absorbing materials with high-efficiency such as thin thickness,li...The problems of electromagnetic wave(EMW)pollution in X and Ku bands(8–18 GHz)are becoming more and more serious.Therefore,it is urgent to design EMW absorbing materials with high-efficiency such as thin thickness,lightweight,wide bandwidth and strong EMW absorption.Inspired by the biomorph of sea cucumber,Nb_(2)CT_(x) MXene@Co nitrogen-doped carbon nanosheet arrays@carbon fiber aerogels(Nb_(2)CT_(x)@Co-NC@CFA,Nb_(2)CT_(x)=niobium carbide)were constructed by self-assembly,in-situ chemical deposition and subsequent pyrolysis.The carbon fiber aerogel,as the basic skeleton of sea cucumber,forms lightweight three-dimensional interconnected conductive network,enhances the dielectric loss and extends the multiple reflection and absorption paths of EMW.As the tentacles of sea cucumber surface,Nb_(2)CT_(x) MXene and Co nitrogen-doped carbon nanosheet arrays exist rich heterogeneous interfaces,which play an important role in improving EMW polarization loss and optimizing impedance matching.The minimum reflection loss(RLmin)of Nb_(2)CT_(x)@Co-NC@CFA reaches−54.7 dB at 9.84 GHz(2.36 mm)with a low filling ratio of 10 wt.%and the effective absorption bandwidth(EAB)of Nb_(2)CT_(x)@Co-NC@CFA reaches 2.96 GHz(8.48–11.44 GHz)with 2.36 mm and 5.2 GHz(12.8–18 GHz)with 1.6 mm,covering most of X and Ku bands by adjusting thickness.The radar cross section(RCS)value of Nb_(2)CT_(x)@Co-NC@CFA is 26.64 dB·m^(2),which is lower than that of the perfect electrical conductor(PEC),indicating that Nb_(2)CT_(x)@Co-NC@CFA can effectively decrease the probability of the target being detected by the radar detector.This work provides ideas for design and development of EMW absorbing materials with high-efficiency EMW absorption in X and Ku bands.展开更多
The electrooxidation of 5-hydroxymethylfurfural(HMFOR)not only offers a green route to attain high-value 2,5-furandicarboxylic acid(FDCA)from biomass,but also is considered as a promising approach to replace the kinet...The electrooxidation of 5-hydroxymethylfurfural(HMFOR)not only offers a green route to attain high-value 2,5-furandicarboxylic acid(FDCA)from biomass,but also is considered as a promising approach to replace the kinetically sluggish OER for future hydrogen production.Herein,we report the construction and structural optimization of Ce-doped ultrasmall Co_(2)P nanoparticles(NPs)in carbon-based nanoarrays to boost HER-coupled HMFOR.We demonstrate that the electronic structure of Co-based electrocatalysts can be positively regulated by Ce doping and the optimized Ce-Co_(2)P-based electrocatalyst only require a low voltage of 1.20 V vs.RHE to achieve 10 m A cm^(-2)for HMFOR with an excellent FDCA Faraday efficiency(FEFDCA)of 98.5%,which are superior to its Ce-free counterpart(1.29 V vs.RHE;FEFDCA=83.9%).When being assembled into a HERcoupled HMFOR system,this bifunctional electrocatalyst can achieve 50 m A cm^(-2)with an ultralow voltage of 1.46 V,which is reduced by 210 m Vas compared with that of its Ce-free counterpart(1.67 V).Quasi-operando experiments and DFTcalculations further reveal the significant roles of Ce doping in promoting the charge transfer between active sites and HMF,and reducing the free energy barrier of intermediate(^(*)HMFCA)dehydrogenation.This study provides new insights into the underlying mechanisms of Ce doping into metal phosphides for boosting HER-coupled HMFOR,developing a facile methodology to construct efficient electrocatalysts for energy storage/conversion systems.展开更多
FeNi-based phosphides are one of the most hopeful electrocatalysts,whereas the significant challenge is to achieve prominent bifunctional catalytic activity with low voltage for water splitting.The morphology and elec...FeNi-based phosphides are one of the most hopeful electrocatalysts,whereas the significant challenge is to achieve prominent bifunctional catalytic activity with low voltage for water splitting.The morphology and electronic structure of FeNi-based phosphides can intensively dominate effective catalysis,therefore their simultaneous regulating is extremely meaningful.Herein,a robust bifunctional catalyst of Zn-implanted FeNi-P nanosheet arrays(Zn-FeNi-P)vertically well-aligned on Ni foam is successfully fabricated by Zn implanting strategy.The Zn fulfills the role of electronic donor due to its low electronegativity to enhance the electronic density of FeNi-P for optimized water dissociation kinetics.Meanwhile,the implantation of Zn into FeNi-P can effectively regulate morphology of the catalyst from thick and irregular nanosheets to ultrathin lamellar structure,which generates enriched catalytic active sites,leading to accelerating electron/mass transport ability.Accordingly,the designed Zn-FeNi-P catalyst manifests remarkable hydrogen evolution reaction(HER)activity with low overpotentials of 55 and 225 mV at 10 and 200 mA·cm^(−2),which is superior to the FeNi-P(82 mV@10 mA·cm^(−2)and 301 mV@200 mA·cm^(−2)),and even out-performing the Pt/C catalyst at a high current density>200 mA·cm^(−2).Moreover,the oxygen evolution reaction(OER)activity of Zn-FeNi-P also has dramatically improved(207 mV@10 mA·cm^(−2))comparable to FeNi-P(221 mV@10 mA·cm^(−2))and RuO_(2)(239 mV@10 mA·cm^(−2)).Noticeably,an electrolyzer based on Zn-FeNi-P electrodes requires a low cell voltage of 1.47 V to achieve 10 mA·cm^(−2),far beyond the catalytic activities of FeNi-P||FeNi-P(1.51 V@10 mA·cm^(−2))and the benchmark RuO_(2)||Pt/C couples(1.56 V@10 mA·cm^(−2)).This Zn-implanting strategy paves a new perspective for the development of admirable bifunctional catalysts.展开更多
Developing efficient and low-cost electrocatalysts for oxygen evolution reaction(OER)with high electrochemical activity and durability for diverse renewable and sustainable energy technologies remains challenging.Here...Developing efficient and low-cost electrocatalysts for oxygen evolution reaction(OER)with high electrochemical activity and durability for diverse renewable and sustainable energy technologies remains challenging.Herein,an ultrasonic-assisted and coordination modulation strategy is developed to construct sandwich-like metal-organic framework(MOF)derived hydroxide nanosheet(NS)arrays/graphene oxide(GO)composite via one-step self-transformation route.Inducing from unsteady state,the dodecahedral ZIF-67 with Co^2+in tetrahedral coordination auto-converts into defect-rich ultrathin layered hydroxides with the interlayered ion NO3-.The self-transforming a-Co(OH)2/GO nanosheet arrays from ZIF-67(Co(OH)2-GNS)change the coordination mode of Co^2+and bring about the exposure of more metal active sites,thereby enhancing the spatial utilization ratio within the framework.As monometal-based electrocatalyst,the optimized Co(OH)2-GNS exhibits remarkable OER catalytic performance evidenced by a low overpotential of 259 mV to achieve a current density of 10 mA·cm-2 in alkaline medium,even exceeding commercial RuO2.During the oxygen evolution process,electron migration can be accelerated by the interfacial/in-plane charge polarization and local electric field,corroborated by the off-axis electron holography.Density functional theory(DFT)calculations further studied the collaboration between ultrathin Co(OH)2 NS and GO,which leads to lower energy barriers of intermediate products and greatly promotes electrocatalytic property.展开更多
Developing highly efficient,easy-to-make and cost-effective bifunctional electrocatalysts for water splitting with lower cell voltages is crucial to producing massive hydrogen fuel.In response,the coupled hierarchical...Developing highly efficient,easy-to-make and cost-effective bifunctional electrocatalysts for water splitting with lower cell voltages is crucial to producing massive hydrogen fuel.In response,the coupled hierarchical Ni/Fe-based MOF nanosheet arrays with embedded metal sulfide nanoclusters onto nickel foam skeleton(denoted as Fe-Ni_(3)S_(2)@NiFe-MOF/NF)are fabricated,in which the Fe-Ni_(3)S_(2) clusters could effectively restrain the aggregation of the layer metal-organic frameworks(MOF)nanosheets and adjust the local electronic structures of MOFs nanosheets.Benefiting from the rapid charge transfer and the exposure of abundant active sites,the well-designed Fe-Ni_(3)S_(2)@NiFe-MOF/NF displays excellent oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)performance.More importantly,when equipped in the alkaline water electrolyzer,the Fe-Ni_(3)S_(2)@Ni Fe-MOF/NF enables the system with a mere 1.6 V for achieving the current density of 10 mA cm^(-2).This work offers a paradigm for designing efficient bifunctional HER/OER electrocatalysts based on the hybrid materials of nanostructured metal sulfide and MOF.展开更多
Owing to the wide range and low cost of sodium resources,sodium-ion batteries(SIBs)have received extensive attention and research.Metal sulfides with high theoretical capacity are used as promising anode materials for...Owing to the wide range and low cost of sodium resources,sodium-ion batteries(SIBs)have received extensive attention and research.Metal sulfides with high theoretical capacity are used as promising anode materials for SIBs.This paper presents the electrochemical performance of the binder-free NiS_(2)nanosheet arrays grown on stainless steel(SS)substrate(NiS_(2)/SS)using an in situ growth and sulfidation strategy as anode for sodium ion batteries.Owing to the close connection between the NiS_(2)nanosheet arrays and the SS current collector,the NiS_(2)/SS anode demonstrates high rate capability with a reversible capacity of 492.5 mAh·g^(-1)at 5.0C rate.Such rate capability is superior to that of NiS_(2)nanoparticles(NiS_(2)/CMC:41.7 mAh·g^(-1)at 5.0C,NiS_(2)/PVDF:7.3 mAh·g^(-1)at 5.0C)and other Ni sulfides(100–450 mAh·g^(-1)at 5.0C)reported.Furthermore,the initial reversible specific capacity and Coulombic efficiency of NiS_(2)/SS are 786.5 mAh·g^(-1)and 81%,respec-tively,demonstrating a better sodium storage ability than those of most NiS_(2)anodes reported for SIBs.In addition,the amorphization and conversion mechanism during the sodiation/desodiation process of NiS_(2)are proposed after investigation by in situ X-ray diffraction(XRD)measurements of intermediate products at successive charge/discharge stages.展开更多
Ni3S2 nanosheet(NS) arrays on Ni foam were fabricated by a simple one-step electrodeposition strategy, and used as a kind of electrode material for asymmetric supercapacitors. The Ni3S2 NS arrays are interconnected, w...Ni3S2 nanosheet(NS) arrays on Ni foam were fabricated by a simple one-step electrodeposition strategy, and used as a kind of electrode material for asymmetric supercapacitors. The Ni3S2 NS arrays are interconnected, which can be regarded as bridges between these individual nanoparticle units. The electrochemical performances were evaluated by cyclic voltammetry and chronopotentiometry techniques in a three-electrode system. The Ni3S2 NS arrays display a specific capacitance of 773.6 F g^-1 at 1 A g^-1, and excellent rate property of 84.3% at 10 A g^-1. The performance of the Ni3S2 NS arrays was further investigated in an asymmetric supercapacitor for potential practical application. The asymmetric supercapacitor using the Ni3S2 electrode and reduced graphene oxide electrode as positive and negative electrodes, respectively, exhibits an energy density of 41.2 W h kg^-1 at 1.6 kW kg^-1. When up to 16 kW kg^-1, it holds 25.3 W h kg^-1.These excellent electrochemical performances are attributed to the improved electronic conductivity and rich redox reaction sites from Ni3S2 NS arrays. Our results indicate that the Ni3S2 NS arrays have great potential for supercapacitors.展开更多
Owing to their safety and low cost,magnesium ion batteries(MIBs)have attracted much attention in recent years.However,the sluggish diffusion dynamics of magnesium ions hampers the search for appropriate cathode materi...Owing to their safety and low cost,magnesium ion batteries(MIBs)have attracted much attention in recent years.However,the sluggish diffusion dynamics of magnesium ions hampers the search for appropriate cathode materials with excellent electrochemical performance.Herein,we design and synthesize a novel flexible three-dimensional-networked composite of iron vanadate nanosheet arrays/carbon cloths(3 D FeVO/CC)as a binder-free cathode for MIBs.Relative to bare FeVO nanosheets,the 3 D binder-free electrode with designed architecture enables a full range of electrochemical potential,including a high specific capacity of270 mA h g^(-1) and an increased life span(over 5000 cycles).Such achievable high-density energy originates from the synergistic optimization of electron and ion kinetics,while the durability benefits from the robust structure that prevents degradation in cycling.The single-phase reaction mechanism of FeVO in the magnesium ion storage process is also explored by in-situ X-ray diffraction and Raman technologies.Moreover,a flexible MIB pouch cell(3 D FeVO/CCIMgNaTi_(3)O_(7)) is assembled and exhibits practical application potential.This work verifies that 3 D FeVO/CC is a potential candidate cathode material that can satisfy the requirements of highperformance MIBs.It also opens a new avenue to improve the electrochemical performance of cathode materials for MIBs.展开更多
Self-standing porous WP2 nanosheet arrays on carbon fiber cloth （WP2 NSs/CC） were synthesized and used as a 3D flexible hydrogen evolution electrode. Because of its 3D porous nanoarray structure, the WP2 NSs/CC exhi...Self-standing porous WP2 nanosheet arrays on carbon fiber cloth （WP2 NSs/CC） were synthesized and used as a 3D flexible hydrogen evolution electrode. Because of its 3D porous nanoarray structure, the WP2 NSs/CC exhibits a remarkable catalytic activity and a high stability. By using the experimental measurements and first-principle calculations, the underlying reasons for the excellent catalytic activity were further explored. Our work makes the present WPz NSs as a promising electrocatalyst for hydrogen evolution and provides a way to design and fabricate efficient hydrogen evolution electrodes through 3D porous nano-arrays architecture.展开更多
Efficient,low-cost,and stable electrocatalysts for water splitting are highly desirable.Herein,three-dimensional(3D)Ni_(2)P nanosheet arrays were fabricated and simultaneously modulated by heterostructure engineering ...Efficient,low-cost,and stable electrocatalysts for water splitting are highly desirable.Herein,three-dimensional(3D)Ni_(2)P nanosheet arrays were fabricated and simultaneously modulated by heterostructure engineering and Mn doping(Mn-doped Ni_(2)O_(3)/Ni_(2)P and Mn-doped Ni_(x)S_(y)/Ni_(2)P)via a facile hydrothermal reaction and subsequent phosphorization and sulfurization.Due to the Mn doping,synergistic effect in the heterostructures,and abundantly exposed active sites from the 3D-nanosheet arrays,Mn-doped Ni_(2)O_(3)/Ni_(2)P and Mn-doped Ni_(x)S_(y)/Ni_(2)P exhibit excellent properties for the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER),respectively.The former achieves an excellent current density of-10 mA cm^(-2) at a low overpotential of 104 mV for HER,while the latter attains 100 mA cm^(-2) for OER at an ultralow overpotential of 290 mV and exhibits superior stability at 50 mA cm^(-2) for 160 h.Impressively,the Mndoped Ni_(2)O_(3)/Ni_(2)P//Mn-doped Ni_(x)S_(y)/Ni_(2)P couple show high overall-water-splitting activity with a cell voltage of 1.65 V at 10 mA cm^(-2) and outstanding durability at 50 mA cm^(-2) for 120 h in an alkaline electrolyzer.This work presents an effective strategy to design and synthesize low-cost and highly active non-noble metal electrocatalysts for overall water splitting through the simultaneous application of heterostructure engineering,foreign-metal-atom doping,and a 3Dnanoarray structure.The strategy brings a paradigm shift toward the mass production of low-cost non-noble metal electrocatalysts for renewable energy devices.展开更多
Mixed metal sulfides have been widely used as anode material of sodium-ion batteries(SIBs)because of their excellent conductivity and sodium ion storage performance.Herein,ReS_(2)@NiS_(2)heterostructures have been tri...Mixed metal sulfides have been widely used as anode material of sodium-ion batteries(SIBs)because of their excellent conductivity and sodium ion storage performance.Herein,ReS_(2)@NiS_(2)heterostructures have been triumphantly designed and prepared through anchoring ReS_(2)nanosheet arrays on the surface of NiS_(2)hollow nanosphere.Specifically,the carbon nanospheres was used as hard template to synthesize NiS_(2)hollow spheres as the substrate and then the ultrathin two-dimensional ReS_(2)nanosheet arrays were uniformly grown on the surface of NiS_(2).The internal hollow property provides sufficient space to relieve the volume expansion,and the outer two-dimensional nanosheet realizes the rapid electron transport and insertion/extraction of Na^(+).Owing to the great improvement of the transport kinetics of Na^(+),NiS_(2)@ReS_(2)heterostructure electrode can achieve a high specific capacity of 400 mAh/g at the high current density of 1 A/g and still maintain a stable cycle stability even after 220 cycles.This hard template method not only paves a new way for the design and construct binary metal sulfide heterostructure electrode materials with outstanding electrochemical performance for Na^(+)batteries but also open up the potential applications of anode materials of SIBs.展开更多
Modifying electrochemical surface area(ECSA)and surface chemistry are promising approaches to enhance the capacities of oxygen cathodes for lithium-oxygen(Li-O_(2))batteries.Although various chemical approaches have b...Modifying electrochemical surface area(ECSA)and surface chemistry are promising approaches to enhance the capacities of oxygen cathodes for lithium-oxygen(Li-O_(2))batteries.Although various chemical approaches have been successfully used to tune the cathode surface,versatile physical techniques including plasma etching etc.could be more effortless and effective than arduous chemical treatments.Herein,for the first time,we propose a facile oxygen plasma treatment to simultaneously etch and modify the surface of Co_(3)O_(4)nanosheet arrays(NAs)cathode for Li-O_(2)batteries.The oxygen plasma not only etches Co_(3)O_(4)nanosheets to enhance the ECSA but also lowers the oxygen vacancy concentration to enable a Co^(3+)-rich surface.In addition,the NA architecture enables the full exposure of oxygen vacancies and surface Co^(3+)that function as the catalytically active sites.Thus,the synergistic effects of enhanced ECSA,modest oxygen vacancy and high surface Co^(3+)achieve a significantly enhanced reversible capacity of 3.45 mAh/cm^(2)for Co_(3)O_(4)NAs.This work not only develops a promising high-capacity cathode for Li-O_(2)batteries,but also provides a facile physical method to simultaneously tune the nanostructure and surface chemistry of energy storage materials.展开更多
基金the National Natural Science Foundation of China(NSFC,Grant No.51972178)the Natural Science Foundation of Ningbo(2022J139)the Ningbo Yongjiang Talent Introduction Programme(2022A-227-G).
文摘Two-dimensional(2D)oxides have been the focus of substantial research interest recently,owing to their fascinating physico-chemical properties.However,fabrication of large-area 2D oxide materials in a controlled manner under mild conditions still remains a formidable challenge.Herein,we develop a facile and universal strategy based on the sonochemistry approach for controllable and large-area growth of quasi-aligned single-crystalline ZnO nanosheets on a Zn substrate(Zn@SC-ZnO)under ambient conditions.The obtained ZnO nanosheets possess the desired exclusively exposed(001)facets,which have been confirmed to play a critical role in significantly reducing the activation energy and facilitating the stripping/plating processes of Zn.Accordingly,the constructed Zn@SC-ZnO||Zn@SC-ZnO symmetric cell has very low polarization overpotential down to~20 mV,with limited dendrite growth and side reactions for Zn anodes.The developed Zn@SC-ZnO//MnO_(2)aqueous Zn-ion batteries(ZIBs)show a voltage efficiency of 88.2%under 500 mA g^(-1)at the stage of 50%depth of discharge,which is state of the art for ZIBs reported to date.Furthermore,the as-assembled large-size cell(5 cm×5 cm)delivers an open circuit potential of 1.648 V,and can be robustly operated under a high current of 20 mA,showing excellent potential for future scalable applications.
基金supported by the National Natural Science Foundation of China(Grant nos.52272201,52072136,52172229,52302303,and 51972257)Yanchang Petroleum-WHUT Joint Program(yc-whlg-2022ky-05)+1 种基金the State Key Laboratory of Advanced Technology for Materials Synthesis and Processing(Wuhan University of Technology,2022-KF-20)Fundamental Research Funds for the Central Universities(2023IVA106)for financial support
文摘FeS_(2)cathode is promising for all-solid-state lithium batteries due to its ultra-high capacity,low cost,and environmental friendliness.However,the poor performances,induced by limited electrode-electrolyte interface,severe volume expansion,and polysulfide shuttle,hinder the application of FeS_(2)in all-solid-state lithium batteries.Herein,an integrated 3D FeS_(2)electrode with full infiltration of Li6PS5Cl sulfide electrolytes is designed to address these challenges.Such a 3D integrated design not only achieves intimate and maximized interfacial contact between electrode and sulfide electrolytes,but also effectively buffers the inner volume change of FeS_(2)and completely eliminates the polysulfide shuttle through direct solid-solid conversion of Li2S/S.Besides,the vertical 3D arrays guarantee direct electron transport channels and horizontally shortened ion diffusion paths,endowing the integrated electrode with a remarkably reduced interfacial impedance and enhanced reaction kinetics.Benefiting from these synergies,the integrated all-solid-state lithium battery exhibits the largest reversible capacity(667 mAh g^(-1)),best rate performance,and highest capacity retention of 82%over 500 cycles at 0.1 C compared to both a liquid battery and non-integrated all-solid-state lithium battery.The cycling performance is among the best reported for FeS_(2)-based all-solid-state lithium batteries.This work presents an innovative synergistic strategy for designing long-cycling high-energy all-solid-state lithium batteries,which can be readily applied to other battery systems,such as lithium-sulfur batteries.
基金sponsored by the National Natural Science Foundation of China (Nos. 51402190, 61574091)Shanghai Sailing Program (18YF1427800)the special funds for theoretical physics of the National Natural Science Foundation of China (No. 11747029)
文摘Photoanodes based on In_2S_3/ZnO heterojunction nanosheet arrays(NSAs) have been fabricated by atomic layer deposition of ZnO over In_2S_3 NSAs, which were in situ grown on fluorine-doped tin oxide glasses via a facile solvothermal process. The as-prepared photoanodes show dramatically enhanced performance for photoelectrochemical(PEC) water splitting, compared to single semiconductor counterparts. The optical and PEC properties of In_2S_3/ZnO NSAs have been optimized by modulating the thickness of the Zn O overlayer. After pairing with ZnO, the NSAs exhibit a broadened absorption range and an increased light absorptance over a wide wavelength region of 250–850 nm. The optimized sample of In_2S_3/ZnO-50 NSAs shows a photocurrent density of 1.642 m A cm^(-2)(1.5 V vs. RHE) and an incident photonto-current efficiency of 27.64% at 380 nm(1.23 V vs.RHE), which are 70 and 116 times higher than those of the pristine In_2S_3 NSAs, respectively. A detailed energy band edge analysis reveals the type-II band alignment of the In_2S_3/ZnO heterojunction, which enables efficient separation and collection of photogenerated carriers,especially with the assistance of positive bias potential, and then results in the significantly increased PEC activity.
基金the National Natural ScienceFoundation of China(Grant Nos.51925207,U1910210,52161145101,51872277,51972067,51902062and 52002083)the Fundamental Research Funds for the Central Universities(WK2060140026)+2 种基金the National Synchrotron Radiation Laboratory(KY2060000173)the Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy(Grant.YLU-DNL Fund 2021002)Guangdong Natural Science Funds for Distinguished Young Scholar(GrantNo.2019B151502039).
文摘Sodium metal battery(SMB)is regarded as a promising candidate for next-generation high-energy battery due to high theoretical capacity and abundant natural resources.However,the growth of sodium dendrites and large volume expansion during the processes of sodium plating and stripping seriously restrict the practical application of SMBs.Here,a three-dimensional skeleton of aluminum nanosheet arrays(Al NSARs)is constructed by a facile etching approach to achieve rapid and reversible Na plating/stripping.The Al NSARs with large geometric specific surface and plentiful cavities can provide rich active nucleation sites,reduce local current density and accommodate Na volume change,which lead to uniform deposition of sodium with dendrite-free morphology.As a result,Na plating/stripping on Al NSARs can stably operate over 650 cycles at 2 mA cm^(-2)/2 mAh cm^(-2)with average Coulombic efficiency(CE)of 100.0%and low potential polarization of 27 mV.Moreover,the full cell of Na_(s)V_(2)(PO_(4))_(3)||Al NSARs@Na can run for over 1800 cycles at a high rate of 20C.These superior properties,combined with relatively low cost and weight of Al,enable our AlNSARs to begreat prospect for practical applications.
基金supported by the National Natural Science Foundation of China(21503051,21563007)the Natural Science Foundation of Guangxi Province(2019GXNSFFA245016,2018GXNSFAA138108)。
文摘Modulate the electronic structure and surface energy by nanostructure and heteroatom doping is an efficient strategy to improve electrocatalytic activity of hydrogen evolution reaction(HER).Herein,nickel incorporated WP_(2) self-supporting nanosheet arrays cathode was synthesized on carbon cloth(Ni-WP_(2) NS/CC)by in-situ phosphating reduction of the Ni-doped WO3.It shows that heteroatom doping and the three-dimensional(3D)nanosheet arrays morphology both facilitate to reduce the interfacial transfer resistance and increase electrochemical-active surface areas,which effectively improve electrocatalytic hydrogen evolution reaction(HER)activity.The optimized catalyst,1%Ni-WP_(2) NS/CC,exhibits an outstanding electrocatalytic performance with an overpotential of 110 m V at 10 m A cm^(-2) and a Tafel slope of 65 m V dec^(-1) in the acid solution.DFT calculations further demonstrate the nickel doping can adjust the intrinsic structure of electronics,lower the Gibbs free energy of adsorption of hydrogen(DGH*),and effectively improve the HER performance.
基金supported by Zhujiang New Stars of Science and Technology (2014J2200061)
文摘One-dimensional(1D, wire-and fiber-shaped)supercapacitors have recently attracted interest due to their roll-up, micrometer size and potential applications in portable or wearable electronics. Herein, a 1D wireshaped electrode was developed based on Fe_3O_4 nanosheet arrays connected on the Fe wire, which was prepared via oxidation of Fe wire in 0.1 M KCl solution(pH 3) with O2-rich environment under 70 °C. The obtained Fe_3O_4 nanosheet arrays displayed a high specific capacitance(20.8 m F cm^(-1) at 10 mV s^(-1)) and long cycling lifespan(91.7% retention after 2500 cycles). Theexcellent performance may attribute to the connected nanosheet structure with abundant open spaces and the intimate contact between the Fe_3O_4 and iron substrate. In addition, a wire-shaped asymmetric supercapacitor was fabricated and had excellent capacitive properties with a high energy density(9 l Wh cm^(-2)) at power density of 532.7 l W cm^(-2) and remarkable long-term cycling performance(99% capacitance retention after 2000 cycles).Considering low cost and earth-abundant electrode material, as well as outstanding electrochemical properties, the assembled supercapacitor will possess enormous potential for practical applications in portable electronic device.
基金supported by the National Natural Science Foundation of China(52272295,52071137,51977071,51802040,and 21802020)the Science and Technology Innovation Program of Hunan Province(2021RC3066 and 2021RC3067)+1 种基金Natural Science Foundation of Hunan Province(2020JJ3004 and 2020JJ4192)financial support of the Fundamental Research Funds for the Central Universities。
文摘Selective CO_(2)-to-CO photoreduction is under intensive research and requires photocatalysts with tuned microstructures to accelerate the reaction kinetics.Here,we report CuInS_(2)nanosheet arrays with sulfur vacancies(VS)grown on the two-dimensional(2D)support of Ti_(3)C_(2)T_(x)MXene for CO_(2)-to-CO photoreduction.Our results reveal that the use of Ti_(3)C_(2)T_(x)induces strong support effect,which causes the hierarchical nanosheet arrays growth of CuInS_(2)and simultaneously leads to charge transfer from CuInS_(2)to Ti_(3)C_(2)T_(x)support,resulting in VSformed in CuInS_(2).The strong support effect based on Ti_(3)C_(2)T_(x)is proven to be applicable to prepare a series of different metal indium sulfide arrays with VS.CuInS_(2)nanosheet arrays with VSsupported on Ti_(3)C_(2)T_(x)benefit the photocatalytic selective reduction of CO_(2)to CO,manifesting a remarkable over 14.8-fold activity enhancement compared with pure CuInS_(2).The experimental and computational investigations pinpoint that VSof CuInS_(2)resulting from the support effect of Ti_(3)C_(2)T_(x)lowers the barrier of the rate-limiting step of^(*)COOH→^(*)OH+^(*)CO,which is the key to the photoactivity enhancement.This work demonstrates MXene support effects and offers an effective approach to regulate the atomic microstructure of metal sulfides toward enhancing photocatalytic performance.
基金financially supported by the National Natural Science Foundation of China and the Civil Aviation Administration of China(No.U1833118)the Open Project Program of High-Tech Organic Fibers Key Laboratory of Sichuan Province(No.PLN2022-10)+3 种基金the Science and Technology Plan Project of Chengdu City(2022-YF05-00411-SN)Science and Technology Planning Project of Sichuan Province(Nos.2023YFQ0090,2024YFHZ0218,2023YFN0016,and 2023YFQ083)Yibin Science and Technology Plan Project(No.2022JB013)Engineering characteristic team of Sichuan University(No.2020SCUNG122).
文摘The problems of electromagnetic wave(EMW)pollution in X and Ku bands(8–18 GHz)are becoming more and more serious.Therefore,it is urgent to design EMW absorbing materials with high-efficiency such as thin thickness,lightweight,wide bandwidth and strong EMW absorption.Inspired by the biomorph of sea cucumber,Nb_(2)CT_(x) MXene@Co nitrogen-doped carbon nanosheet arrays@carbon fiber aerogels(Nb_(2)CT_(x)@Co-NC@CFA,Nb_(2)CT_(x)=niobium carbide)were constructed by self-assembly,in-situ chemical deposition and subsequent pyrolysis.The carbon fiber aerogel,as the basic skeleton of sea cucumber,forms lightweight three-dimensional interconnected conductive network,enhances the dielectric loss and extends the multiple reflection and absorption paths of EMW.As the tentacles of sea cucumber surface,Nb_(2)CT_(x) MXene and Co nitrogen-doped carbon nanosheet arrays exist rich heterogeneous interfaces,which play an important role in improving EMW polarization loss and optimizing impedance matching.The minimum reflection loss(RLmin)of Nb_(2)CT_(x)@Co-NC@CFA reaches−54.7 dB at 9.84 GHz(2.36 mm)with a low filling ratio of 10 wt.%and the effective absorption bandwidth(EAB)of Nb_(2)CT_(x)@Co-NC@CFA reaches 2.96 GHz(8.48–11.44 GHz)with 2.36 mm and 5.2 GHz(12.8–18 GHz)with 1.6 mm,covering most of X and Ku bands by adjusting thickness.The radar cross section(RCS)value of Nb_(2)CT_(x)@Co-NC@CFA is 26.64 dB·m^(2),which is lower than that of the perfect electrical conductor(PEC),indicating that Nb_(2)CT_(x)@Co-NC@CFA can effectively decrease the probability of the target being detected by the radar detector.This work provides ideas for design and development of EMW absorbing materials with high-efficiency EMW absorption in X and Ku bands.
基金supported from the Natural Science Foundation of Guangdong Province(2023B1515040005)the State Key Laboratory of Pulp and Paper Engineering(2022PY05)the National Natural Science Foundation of China(22138003,21825802)
文摘The electrooxidation of 5-hydroxymethylfurfural(HMFOR)not only offers a green route to attain high-value 2,5-furandicarboxylic acid(FDCA)from biomass,but also is considered as a promising approach to replace the kinetically sluggish OER for future hydrogen production.Herein,we report the construction and structural optimization of Ce-doped ultrasmall Co_(2)P nanoparticles(NPs)in carbon-based nanoarrays to boost HER-coupled HMFOR.We demonstrate that the electronic structure of Co-based electrocatalysts can be positively regulated by Ce doping and the optimized Ce-Co_(2)P-based electrocatalyst only require a low voltage of 1.20 V vs.RHE to achieve 10 m A cm^(-2)for HMFOR with an excellent FDCA Faraday efficiency(FEFDCA)of 98.5%,which are superior to its Ce-free counterpart(1.29 V vs.RHE;FEFDCA=83.9%).When being assembled into a HERcoupled HMFOR system,this bifunctional electrocatalyst can achieve 50 m A cm^(-2)with an ultralow voltage of 1.46 V,which is reduced by 210 m Vas compared with that of its Ce-free counterpart(1.67 V).Quasi-operando experiments and DFTcalculations further reveal the significant roles of Ce doping in promoting the charge transfer between active sites and HMF,and reducing the free energy barrier of intermediate(^(*)HMFCA)dehydrogenation.This study provides new insights into the underlying mechanisms of Ce doping into metal phosphides for boosting HER-coupled HMFOR,developing a facile methodology to construct efficient electrocatalysts for energy storage/conversion systems.
基金the support of this research by the National Key Research and Development(R&D)Program of China(No.2018YFE0201704)the National Natural Science Foundation of China(Nos.91961111 and 21901064)+3 种基金the Natural Science Foundation of Heilongjiang Province(No.ZD2021B003)Postdo ctoral Science Foundation of Heilongjiang Province(No.LBH-Z18231)the Fundamental Research Project for Universities in Heilongjiang Province(No.YSTSXK 135409211)University Nursing Program for YoungScholars with Creative Talents in Heilongjiang Province(No.UNPYSCT2020004).
文摘FeNi-based phosphides are one of the most hopeful electrocatalysts,whereas the significant challenge is to achieve prominent bifunctional catalytic activity with low voltage for water splitting.The morphology and electronic structure of FeNi-based phosphides can intensively dominate effective catalysis,therefore their simultaneous regulating is extremely meaningful.Herein,a robust bifunctional catalyst of Zn-implanted FeNi-P nanosheet arrays(Zn-FeNi-P)vertically well-aligned on Ni foam is successfully fabricated by Zn implanting strategy.The Zn fulfills the role of electronic donor due to its low electronegativity to enhance the electronic density of FeNi-P for optimized water dissociation kinetics.Meanwhile,the implantation of Zn into FeNi-P can effectively regulate morphology of the catalyst from thick and irregular nanosheets to ultrathin lamellar structure,which generates enriched catalytic active sites,leading to accelerating electron/mass transport ability.Accordingly,the designed Zn-FeNi-P catalyst manifests remarkable hydrogen evolution reaction(HER)activity with low overpotentials of 55 and 225 mV at 10 and 200 mA·cm^(−2),which is superior to the FeNi-P(82 mV@10 mA·cm^(−2)and 301 mV@200 mA·cm^(−2)),and even out-performing the Pt/C catalyst at a high current density>200 mA·cm^(−2).Moreover,the oxygen evolution reaction(OER)activity of Zn-FeNi-P also has dramatically improved(207 mV@10 mA·cm^(−2))comparable to FeNi-P(221 mV@10 mA·cm^(−2))and RuO_(2)(239 mV@10 mA·cm^(−2)).Noticeably,an electrolyzer based on Zn-FeNi-P electrodes requires a low cell voltage of 1.47 V to achieve 10 mA·cm^(−2),far beyond the catalytic activities of FeNi-P||FeNi-P(1.51 V@10 mA·cm^(−2))and the benchmark RuO_(2)||Pt/C couples(1.56 V@10 mA·cm^(−2)).This Zn-implanting strategy paves a new perspective for the development of admirable bifunctional catalysts.
基金This work was supported by the National Basic Research Program of China(No.2018YFA209102)the National Natural Science Foundation of China(Nos.11727807,51725101,51672050,and 61790581).
文摘Developing efficient and low-cost electrocatalysts for oxygen evolution reaction(OER)with high electrochemical activity and durability for diverse renewable and sustainable energy technologies remains challenging.Herein,an ultrasonic-assisted and coordination modulation strategy is developed to construct sandwich-like metal-organic framework(MOF)derived hydroxide nanosheet(NS)arrays/graphene oxide(GO)composite via one-step self-transformation route.Inducing from unsteady state,the dodecahedral ZIF-67 with Co^2+in tetrahedral coordination auto-converts into defect-rich ultrathin layered hydroxides with the interlayered ion NO3-.The self-transforming a-Co(OH)2/GO nanosheet arrays from ZIF-67(Co(OH)2-GNS)change the coordination mode of Co^2+and bring about the exposure of more metal active sites,thereby enhancing the spatial utilization ratio within the framework.As monometal-based electrocatalyst,the optimized Co(OH)2-GNS exhibits remarkable OER catalytic performance evidenced by a low overpotential of 259 mV to achieve a current density of 10 mA·cm-2 in alkaline medium,even exceeding commercial RuO2.During the oxygen evolution process,electron migration can be accelerated by the interfacial/in-plane charge polarization and local electric field,corroborated by the off-axis electron holography.Density functional theory(DFT)calculations further studied the collaboration between ultrathin Co(OH)2 NS and GO,which leads to lower energy barriers of intermediate products and greatly promotes electrocatalytic property.
基金financially supported by the Natural Science Foundation of Shandong Province (ZR2020ZD10)the National Natural Science Foundation of China (21775142)。
文摘Developing highly efficient,easy-to-make and cost-effective bifunctional electrocatalysts for water splitting with lower cell voltages is crucial to producing massive hydrogen fuel.In response,the coupled hierarchical Ni/Fe-based MOF nanosheet arrays with embedded metal sulfide nanoclusters onto nickel foam skeleton(denoted as Fe-Ni_(3)S_(2)@NiFe-MOF/NF)are fabricated,in which the Fe-Ni_(3)S_(2) clusters could effectively restrain the aggregation of the layer metal-organic frameworks(MOF)nanosheets and adjust the local electronic structures of MOFs nanosheets.Benefiting from the rapid charge transfer and the exposure of abundant active sites,the well-designed Fe-Ni_(3)S_(2)@NiFe-MOF/NF displays excellent oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)performance.More importantly,when equipped in the alkaline water electrolyzer,the Fe-Ni_(3)S_(2)@Ni Fe-MOF/NF enables the system with a mere 1.6 V for achieving the current density of 10 mA cm^(-2).This work offers a paradigm for designing efficient bifunctional HER/OER electrocatalysts based on the hybrid materials of nanostructured metal sulfide and MOF.
基金the National Natural Science Foundation of China(No.21673051)the Department of Science and Technology of Guangdong Province(No.2019A050510043)the Department of Science and Technology of Zhuhai City,China(No.ZH22017001200059PWC)。
文摘Owing to the wide range and low cost of sodium resources,sodium-ion batteries(SIBs)have received extensive attention and research.Metal sulfides with high theoretical capacity are used as promising anode materials for SIBs.This paper presents the electrochemical performance of the binder-free NiS_(2)nanosheet arrays grown on stainless steel(SS)substrate(NiS_(2)/SS)using an in situ growth and sulfidation strategy as anode for sodium ion batteries.Owing to the close connection between the NiS_(2)nanosheet arrays and the SS current collector,the NiS_(2)/SS anode demonstrates high rate capability with a reversible capacity of 492.5 mAh·g^(-1)at 5.0C rate.Such rate capability is superior to that of NiS_(2)nanoparticles(NiS_(2)/CMC:41.7 mAh·g^(-1)at 5.0C,NiS_(2)/PVDF:7.3 mAh·g^(-1)at 5.0C)and other Ni sulfides(100–450 mAh·g^(-1)at 5.0C)reported.Furthermore,the initial reversible specific capacity and Coulombic efficiency of NiS_(2)/SS are 786.5 mAh·g^(-1)and 81%,respec-tively,demonstrating a better sodium storage ability than those of most NiS_(2)anodes reported for SIBs.In addition,the amorphization and conversion mechanism during the sodiation/desodiation process of NiS_(2)are proposed after investigation by in situ X-ray diffraction(XRD)measurements of intermediate products at successive charge/discharge stages.
基金the financial support from the National Key R&D Program of China (2018YFF0215200)the Natural Science Foundation of Liaoning Province (201602104)+2 种基金the Support Program for Innovative Talents in Liaoning University (LR2017061)the Basic Research Project of Liaoning Province (LF2017007)the Scientific Public Welfare Research Foundation of Liaoning Province (20170054)
文摘Ni3S2 nanosheet(NS) arrays on Ni foam were fabricated by a simple one-step electrodeposition strategy, and used as a kind of electrode material for asymmetric supercapacitors. The Ni3S2 NS arrays are interconnected, which can be regarded as bridges between these individual nanoparticle units. The electrochemical performances were evaluated by cyclic voltammetry and chronopotentiometry techniques in a three-electrode system. The Ni3S2 NS arrays display a specific capacitance of 773.6 F g^-1 at 1 A g^-1, and excellent rate property of 84.3% at 10 A g^-1. The performance of the Ni3S2 NS arrays was further investigated in an asymmetric supercapacitor for potential practical application. The asymmetric supercapacitor using the Ni3S2 electrode and reduced graphene oxide electrode as positive and negative electrodes, respectively, exhibits an energy density of 41.2 W h kg^-1 at 1.6 kW kg^-1. When up to 16 kW kg^-1, it holds 25.3 W h kg^-1.These excellent electrochemical performances are attributed to the improved electronic conductivity and rich redox reaction sites from Ni3S2 NS arrays. Our results indicate that the Ni3S2 NS arrays have great potential for supercapacitors.
基金supported by the National Key Research and Development Program of China(2020YFA0715000)the National Natural Science Foundation of China(51832004 and 51972259)+1 种基金the Natural Science Foundation of Hubei Province(2019CFA001)Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory(XHT2020-003)。
文摘Owing to their safety and low cost,magnesium ion batteries(MIBs)have attracted much attention in recent years.However,the sluggish diffusion dynamics of magnesium ions hampers the search for appropriate cathode materials with excellent electrochemical performance.Herein,we design and synthesize a novel flexible three-dimensional-networked composite of iron vanadate nanosheet arrays/carbon cloths(3 D FeVO/CC)as a binder-free cathode for MIBs.Relative to bare FeVO nanosheets,the 3 D binder-free electrode with designed architecture enables a full range of electrochemical potential,including a high specific capacity of270 mA h g^(-1) and an increased life span(over 5000 cycles).Such achievable high-density energy originates from the synergistic optimization of electron and ion kinetics,while the durability benefits from the robust structure that prevents degradation in cycling.The single-phase reaction mechanism of FeVO in the magnesium ion storage process is also explored by in-situ X-ray diffraction and Raman technologies.Moreover,a flexible MIB pouch cell(3 D FeVO/CCIMgNaTi_(3)O_(7)) is assembled and exhibits practical application potential.This work verifies that 3 D FeVO/CC is a potential candidate cathode material that can satisfy the requirements of highperformance MIBs.It also opens a new avenue to improve the electrochemical performance of cathode materials for MIBs.
文摘Self-standing porous WP2 nanosheet arrays on carbon fiber cloth （WP2 NSs/CC） were synthesized and used as a 3D flexible hydrogen evolution electrode. Because of its 3D porous nanoarray structure, the WP2 NSs/CC exhibits a remarkable catalytic activity and a high stability. By using the experimental measurements and first-principle calculations, the underlying reasons for the excellent catalytic activity were further explored. Our work makes the present WPz NSs as a promising electrocatalyst for hydrogen evolution and provides a way to design and fabricate efficient hydrogen evolution electrodes through 3D porous nano-arrays architecture.
基金supported by the Department of Science and Technology of Guangdong Province(2019A050510043)the Department of Science and Technology of Zhuhai City(ZH22017001200059PWC)。
文摘Efficient,low-cost,and stable electrocatalysts for water splitting are highly desirable.Herein,three-dimensional(3D)Ni_(2)P nanosheet arrays were fabricated and simultaneously modulated by heterostructure engineering and Mn doping(Mn-doped Ni_(2)O_(3)/Ni_(2)P and Mn-doped Ni_(x)S_(y)/Ni_(2)P)via a facile hydrothermal reaction and subsequent phosphorization and sulfurization.Due to the Mn doping,synergistic effect in the heterostructures,and abundantly exposed active sites from the 3D-nanosheet arrays,Mn-doped Ni_(2)O_(3)/Ni_(2)P and Mn-doped Ni_(x)S_(y)/Ni_(2)P exhibit excellent properties for the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER),respectively.The former achieves an excellent current density of-10 mA cm^(-2) at a low overpotential of 104 mV for HER,while the latter attains 100 mA cm^(-2) for OER at an ultralow overpotential of 290 mV and exhibits superior stability at 50 mA cm^(-2) for 160 h.Impressively,the Mndoped Ni_(2)O_(3)/Ni_(2)P//Mn-doped Ni_(x)S_(y)/Ni_(2)P couple show high overall-water-splitting activity with a cell voltage of 1.65 V at 10 mA cm^(-2) and outstanding durability at 50 mA cm^(-2) for 120 h in an alkaline electrolyzer.This work presents an effective strategy to design and synthesize low-cost and highly active non-noble metal electrocatalysts for overall water splitting through the simultaneous application of heterostructure engineering,foreign-metal-atom doping,and a 3Dnanoarray structure.The strategy brings a paradigm shift toward the mass production of low-cost non-noble metal electrocatalysts for renewable energy devices.
基金supported by the Natural Science Foundation of Guangdong Province(No.2020A1515010886).
文摘Mixed metal sulfides have been widely used as anode material of sodium-ion batteries(SIBs)because of their excellent conductivity and sodium ion storage performance.Herein,ReS_(2)@NiS_(2)heterostructures have been triumphantly designed and prepared through anchoring ReS_(2)nanosheet arrays on the surface of NiS_(2)hollow nanosphere.Specifically,the carbon nanospheres was used as hard template to synthesize NiS_(2)hollow spheres as the substrate and then the ultrathin two-dimensional ReS_(2)nanosheet arrays were uniformly grown on the surface of NiS_(2).The internal hollow property provides sufficient space to relieve the volume expansion,and the outer two-dimensional nanosheet realizes the rapid electron transport and insertion/extraction of Na^(+).Owing to the great improvement of the transport kinetics of Na^(+),NiS_(2)@ReS_(2)heterostructure electrode can achieve a high specific capacity of 400 mAh/g at the high current density of 1 A/g and still maintain a stable cycle stability even after 220 cycles.This hard template method not only paves a new way for the design and construct binary metal sulfide heterostructure electrode materials with outstanding electrochemical performance for Na^(+)batteries but also open up the potential applications of anode materials of SIBs.
基金supported by grants from the National Natural Science Foundation of China(Nos.22075219 and 51972257)the National Key Research Program of China(No.2016YFA0202602)the Research Start-Up Fund from Wuhan University of Technology.
文摘Modifying electrochemical surface area(ECSA)and surface chemistry are promising approaches to enhance the capacities of oxygen cathodes for lithium-oxygen(Li-O_(2))batteries.Although various chemical approaches have been successfully used to tune the cathode surface,versatile physical techniques including plasma etching etc.could be more effortless and effective than arduous chemical treatments.Herein,for the first time,we propose a facile oxygen plasma treatment to simultaneously etch and modify the surface of Co_(3)O_(4)nanosheet arrays(NAs)cathode for Li-O_(2)batteries.The oxygen plasma not only etches Co_(3)O_(4)nanosheets to enhance the ECSA but also lowers the oxygen vacancy concentration to enable a Co^(3+)-rich surface.In addition,the NA architecture enables the full exposure of oxygen vacancies and surface Co^(3+)that function as the catalytically active sites.Thus,the synergistic effects of enhanced ECSA,modest oxygen vacancy and high surface Co^(3+)achieve a significantly enhanced reversible capacity of 3.45 mAh/cm^(2)for Co_(3)O_(4)NAs.This work not only develops a promising high-capacity cathode for Li-O_(2)batteries,but also provides a facile physical method to simultaneously tune the nanostructure and surface chemistry of energy storage materials.
