The electrochemical conversion of nitrate,commonly found in industrial effluents and contaminated groundwater,into ammonia offers a sustainable strategy for both wastewater remediation and ammonia production.However,m...The electrochemical conversion of nitrate,commonly found in industrial effluents and contaminated groundwater,into ammonia offers a sustainable strategy for both wastewater remediation and ammonia production.However,most existing catalysts exhibit limited activity and stability,particularly under industrial-level current density.Here we present a straightforward hydrothermalcalcination method to in situ fabricate Cu-doped Co_(3)O_(4)nanoneedle arrays on three-dimensional porous copper foam(Cu-Co_(3)O_(4)/CF).The resulting electrode delivers an industrial-sc ale current density of~1000 m A cm^(-2),a high NH_(3) yield rate of 58.4 mg h^(-1)cm^(-2),and a Faradaic efficiency of 98.3%at-0.5 V versus RHE.The outstanding performance under high current density highlights the significant practical potential of Cu-Co_(3)O_(4)/CF for large-scale applications.Density functional theory(DFT)calculations combined with experimental analysis demonstrate that Cu incorporation optimizes NO_(3)^(-)adsorption energy.More importantly,the doping of Cu accelerates the kinetics of the Volmer step(H_(2)O→*H+*OH),which provides protons for the hydrogenation pathway.This promotes the selective formation of NH3 during the electrochemical nitrate reduction reaction(NO_(3)RR).Overall,this work provides fundamental insights into designing efficient transition metal oxide catalysts for nitrate valorization.展开更多
With the sustainable and efficient development of aqueous zinc ion batteries(AZIBs),the research on addressing the issues of the adaptability and durability of zinc anodes has been hot-topic and is still of great chal...With the sustainable and efficient development of aqueous zinc ion batteries(AZIBs),the research on addressing the issues of the adaptability and durability of zinc anodes has been hot-topic and is still of great challenge.In this work,inspired by the sand treatment and afforestation of the Gobi Beach in Northwest China to ameliorate the problem of wind and sand encroachment,we propose a material with a morphology similar to that of a“shelter forest”,CuSiO_(3)nanoneedles arrays grown on both sides of reduced graphene oxide(rGO@CuSi),as a coating layer on the zinc metal surface to guide Zn gradient deposition.The presence of rGO improves the electrical conductivity of CuSiO_(3),and the finite element simulation of the electric field and Zn^(2+)concentration proves that the electric field distribution can be effectively homogenized and the local current density can be reduced for the rGO@CuSi-Zn electrode with the surface presenting the shape of a protective forest.This is due to the abundant pores between the nano-needle array structures on the surface of the electrode,which provide high electron and ion transport paths,and are conducive to achieving uniform Zn deposition,like the principle of wind-sand stabilization by protective forest.Both electrochemical experiments and density functional theory calculations show that the negatively charged surface of r GO@CuSi with good Zn affinity is more capable of guiding Zn^(2+)transport.Thanks to its inherent material and structural characteristics,the r GO@CuSi-Zn anode has a high specific capacity and good cycling stability.This study provides insight for interface engineering like protective forest to accelerate the commercialization of high-performance Zn-based batteries.展开更多
Cu-based catalysts are the most promising candidates for electrochemical CO_(2)reduction(CO_(2)RR)to multi-carbon(C_(2))products.Optimizing the C-C coupling process,the rate-determining step for C_(2)product generatio...Cu-based catalysts are the most promising candidates for electrochemical CO_(2)reduction(CO_(2)RR)to multi-carbon(C_(2))products.Optimizing the C-C coupling process,the rate-determining step for C_(2)product generation,is an important strategy to improve the production and selectivity of the C_(2)products.In this study,we determined that the local electric field can promote the C-C coupling reaction and enhance CO_(2)electroreduction to C_(2)products.First,finite-element simulations indicated that the high curvature of the Cu nanoneedles results in a large local electric field on their tips.Density functional theory(DFT)calculations proved that a large electric field can promote C-C coupling.Motivated by this prediction,we prepared a series of Cu catalysts with different curvatures.The Cu nanoneedles(NNs)exhibited the largest number of curvatures,followed by the Cu nanorods(NRs),and Cu nanoparticles(NPs).The Cu NNs contained the highest concentration of adsorbed K+,which resulted in the highest local electric field on the needles.CO adsorption sensor tests indicated that the Cu NNs exhibited the strongest CO adsorption ability,and in-situ Fourier-transform infrared spectroscopy(FTIR)showed the strongest*COCO and*CO signals for the Cu NNs.These experimental results demonstrate that high-curvature nanoneedles can induce a large local electric field,thus promoting C-C coupling.As a result,the Cu NNs show a maximum FEC_(2)of 44%for CO_(2)RR at a low potential(-0.6 V vs.RHE),which is approximately 2.2 times that of the Cu NPs.This work provides an effective strategy for enhancing the production of multi-carbon products during CO_(2)RR.展开更多
Bimetallic Ni–Co sulfides are outstanding pseudocapacitive materials with high electrochemical activity and excellent energy storage performance as electrodes for high-performance supercapacitors.In this study,a nove...Bimetallic Ni–Co sulfides are outstanding pseudocapacitive materials with high electrochemical activity and excellent energy storage performance as electrodes for high-performance supercapacitors.In this study,a novel urchin-like NiCo2S4@mesocarbon microbead(NCS@MCMB) composite with a core–shell structure was prepared by a facile two-step hydrothermal method.The highly conductive MCMBs offered abundant adsorption sites for the growth of NCS nanoneedles,which allowed each nanoneedle to fully unfold without aggregation,resulting in improved NCS utilization and efficient electron/ion transferin the electrolyte.When applied as an electrode material for supercapacitors,the composite exhibited a maximum specific capacitance of 936 Fg-1 at 1 Ag-1 and a capacitance retention of 94% after 3000 cycles at 5 Ag-1,because of the synergistic effect of MCMB and NCS.Moreover,we fabricated an asymmetric supercapacitor based on the NCS@MCMB composite,which exhibited enlarged voltage windows and could power a light-emitting diode device for several minutes,further demonstrating the exceptional electrochemical performance of the NCS@MCMB composite.展开更多
The suppression of the recombination of electrons and holes(e–h)and the enhancement of the light absorption of semiconductors are two key points toward efficient photocatalytic degradation.Here,we report a few-layer ...The suppression of the recombination of electrons and holes(e–h)and the enhancement of the light absorption of semiconductors are two key points toward efficient photocatalytic degradation.Here,we report a few-layer g-C_3N_4/α-MoO_(3)nanoneedles(flg-C_3N_4/α-MoO_(3)NNs)all-solid-state Z-scheme mechanism photocatalyst synthesized via a typical hydrothermal method in a controlled manner.The recombination of the photo-induced e–h pairs could be effectively restrained by the Z-scheme passageway between the flg-C_3N_4 andα-MoO_(3)NNs in the composite,which could also promise a high redox ability to degrade pollutants.And it became possible for the prepared photocatalyst to absorb light in a wide range of wavelengths.The detailed mechanism was studied by electron spin-resonance spectroscopy(ESR).The low-dimensional nanostructure of the two constituents(α-MoO_(3)NNs with one-dimensional structure and flg-C_3N_4 with two-dimensional structure)endowed the composite with varieties of excellent physicochemical properties,which facilitated the transfer and diffusion of the photoelectrons and increased the specific surface area and the active sites.The 10 wt%flg-C_3N_4/α-MoO_(3)NNs showed the best photocatalytic performance toward RhB degradation,the rate of which was 71.86%,~2.6 times higher than that ofα-MoO_(3)NNs.展开更多
Single-crystal SrCO3 nanoneedles were synthesized in reverse micelles at low temperature. The products were characterized by X-ray diffraction, X-ray energy dispersive spectrometer, transmission electron microscopy an...Single-crystal SrCO3 nanoneedles were synthesized in reverse micelles at low temperature. The products were characterized by X-ray diffraction, X-ray energy dispersive spectrometer, transmission electron microscopy and selected area electronic diffraction. The influences of experimental conditions on the morphologies of the products were discussed. The growth mechanism of SrCO3 nanoneedles in reverse micelles were proposed.展开更多
A green synthesis method to produce silver nanoneedles was described using shallot and apricot tree gum（ATG）.A fast,simple,and low cost method was used to synthesize silver with nanoparticle and nanoneedle shape fro...A green synthesis method to produce silver nanoneedles was described using shallot and apricot tree gum（ATG）.A fast,simple,and low cost method was used to synthesize silver with nanoparticle and nanoneedle shape from the silver nitrate solution.Shallot as a reducing agent and apricot tree gum（ATG） as a stabilizer and a capping agent were utilized to reduce and form silver ions into silver atoms with needle and particle shape.Moreover,high crystalline structures of silver nanoparticles（AgNPs） with diameters of 8-20 nm and silver nanoneedles with average diameters of 50-60 nm and lengths of 5-10 μm were consequently synthesized by shallot and the mixture of shallot and ATG.A self-assembly mechanism was proposed to indicate the formation of needle-like structures of spherical Ag NPs via carbon chains of ATG.The results indicate that the presence of ATG with shallot can transfer the reduced Ag NPs into the silver nanoneedle.The findings were characterized using X-ray diffraction（XRD）,ultra violet visible（UV-Vis） spectrometry,field emission scanning electron microscopy（FESEM）,and transmission electron microscopy（TEM） techniques.展开更多
Although lithium(Li)metal delivers the highest theoretical capacity as a battery anode,its high reactivity can generate Li dendrites and"dead"Li during cycling,resulting in poor reversibility and low Li util...Although lithium(Li)metal delivers the highest theoretical capacity as a battery anode,its high reactivity can generate Li dendrites and"dead"Li during cycling,resulting in poor reversibility and low Li utilization.Inducing uniform Li plating/stripping is the core of solving these problems.Herein,we design a highly lithiophilic carbon film with an outer sheath of the nanoneedle arrays to induce homogeneous Li plating/stripping.The excellent conductivity and 3D framework of the carbon film not only offer fast charge transport across the entire electrode but also mitigate the volume change of Li metal during cycling.The abundant lithiophilic sites ensure stable Li plating/stripping,thereby inhibiting the Li dendritic growth and"dead"Li formation.The resulting composite anode allows for stable Li stripping/plating under 0.5 mA cm^(-2) with a capacity of 0.5 mA h cm^(-2) for 4000 h and 3 mA cm^(-2) with a capacity of3 mA h cm^(-2) for 1000 h.The Ex-SEM analysis reveals that lithiophilic property is different at the bottom,top,or channel in the structu re,which can regulate a bottom-up uniform Li deposition behavior.Full cells paired with LFP show a stable capacity of 155 mA h g^(-1) under a current density of 0.5C.The pouch cell can keep powering light-emitting diode even under 180°bending,suggesting its good flexibility and great practical applications.展开更多
Self-supported core–shell Co_(9)S_(8)@NiCo_(2)O_(4) hollow nanoneedle arrays are prepared on carbon fibers(CFs)through a facile two-step hydrothermal and electrodeposition method for high performance supercapacitors....Self-supported core–shell Co_(9)S_(8)@NiCo_(2)O_(4) hollow nanoneedle arrays are prepared on carbon fibers(CFs)through a facile two-step hydrothermal and electrodeposition method for high performance supercapacitors.Within the hybrid nanostructures,the high conductivity Co_(9)S_(8) hollow nanoneedles can act as backbones for anchoring the NiCo_(2)O_(4) nanosheets with high capacity.As a result,the hierarchical hybrid structure exhibits a high specific capacitance of 1022.5 F g^(−1) at a current density of 1 A g^(−1).Moreover,an asymmetric supercapacitor(ASC)is successfully assembled by using the core–shell Co_(9)S_(8)@NiCo_(2)O_(4) nanoneedle arrays on carbon fibers as the positive electrode and activated carbon(AC)as the negative electrode,exhibiting a high energy density of 24.85 W h kg^(−1) at a power density of 222 W kg^(−1) as well as a long-term cycling performance with 88.9%initial capacitance retention.Two ASC devices in series can power three red or white parallel LEDs.Therefore,these results suggest that this core–shell hybrid nanostructure has great potential for energy storage systems.展开更多
In this work,mesoporous NiCo_(2)O_(4) nanoneedle arrays grown on a nickel foam substrate are fabricated by a facile hydrothermal route.The as-synthesized NiCo_(2)O_(4) products as binder-free electrodes for supercapac...In this work,mesoporous NiCo_(2)O_(4) nanoneedle arrays grown on a nickel foam substrate are fabricated by a facile hydrothermal route.The as-synthesized NiCo_(2)O_(4) products as binder-free electrodes for supercapacitors show a superior discharge areal capacity of 0.998 C cm^(-2) at a current density of 2 mA cm^(-2),excellent rate performance(60.25% retention with current density increasing from 2 mA cm^(-2) to 200 mA cm^(-2))and outstanding cycling stability(about 19.3% loss after 12000 cycles at a current density of 20 mA cm^(-2)).An assembled supercapacitor using a NiCo_(2)O_(4) electrode as the positive electrode delivers a volumetric energy density of 0.33 mW h cm^(-3) at a volumetric power density of 12 mW h cm^(-3) and still achieves 63.6% retention with the volumetric power density increasing to 120 mW h cm^(-3).Surprisingly,140.6% capacity retention is attained after 8000 cycles at 10 mA cm^(-2).展开更多
Inflammatory bowel disease(IBD)is a chronic and refractory condition characterized by disrupted epithelial barrier,dysregulated immune balance,and altered gut microbiota.Nano-enabled interventions for restoring gut ho...Inflammatory bowel disease(IBD)is a chronic and refractory condition characterized by disrupted epithelial barrier,dysregulated immune balance,and altered gut microbiota.Nano-enabled interventions for restoring gut homeostasis have the potential to alleviate inflammation in IBD.Herein,we developed a combination of olsalazine(Olsa)-based nanoneedles and microbiota-regulating inulin gel to reshape intestinal homeostasis and relieve inflammation.The Olsa-derived nanoneedles exhibited reactive oxygen species scavenging ability and anti-inflammatory effects in lipopolysaccharide-simulated macrophages.The composite of nanoneedles and inulin gel(Cu2(Olsa)/Gel)displayed a macroporous structure,improved bio-adhesion,and enhanced colon retention after oral administration.Mechanistically,the composite effectively downregulated pro-inflammatory cytokine levels and promoted epithelial barrier repair through anti-inflammatory and antioxidant therapies,resulting in significant alleviation of colitis in three animal models of IBD.Furthermore,analysis of gut microbiota revealed that Cu2(Olsa)/Gel treatment increased the diversity of intestinal microflora and decreased the relative abundance of pathogenic bacteria such as Proteobacteria.Overall,this study provides a self-delivering nanodrug and dietary fiber hydrogel composite for IBD therapy,offering an efficient approach to restore intestinal homeostasis.展开更多
Ultra-dispersed Ni nanoparticles(7.5 nm)on nitrogen-doped carbon nanoneedles(Ni@NCNs)were prepared by simple pyrolysis of Ni-based metal–organic-framework for selective hydrogenation of halogenated nitrobenzenes to c...Ultra-dispersed Ni nanoparticles(7.5 nm)on nitrogen-doped carbon nanoneedles(Ni@NCNs)were prepared by simple pyrolysis of Ni-based metal–organic-framework for selective hydrogenation of halogenated nitrobenzenes to corresponding anilines.Two different crystallization methods(stirring and static)were compared and the optimal pyrolysis temperature was explored.Ni@NCNs were systematically characterized by wide analytical techniques.In the hydrogenation of p-chloronitrobenzene,Ni@NCNs-600(pyrolyzed at 600°C)exhibited extraordinarily high performance with 77.9 h^(–1)catalytic productivity and>99%p-chloroaniline selectivity at full p-chloronitrobenzene conversion under mild conditions(90°C,1.5 MPa H2),showing obvious superiority compared with reported Ni-based catalysts.Notably,the reaction smoothly proceeded at room temperature with full conversion and>99%selectivity.Moreover,Ni@NCNs-600 afforded good tolerance to various nitroarenes substituted by sensitive groups(halogen,nitrile,keto,carboxylic,etc.),and could be easily recycled by magnetic separation and reused for 5 times without deactivation.The adsorption tests showed that the preferential adsorption of–NO2 on the catalyst can restrain the dehalogenation of p-chloronitrobenzene,thus achieving high p-chloroaniline selectivity.While the high activity can be attributed to high Ni dispersion,special morphology,and rich pore structure of the catalyst.展开更多
CONSPECTUS:Diamond nanomaterials have attracted significant interest in recent years due to their unique physical and chemical properties.Their exceptional mechanical strength,chemical stability,biocompatibility,and h...CONSPECTUS:Diamond nanomaterials have attracted significant interest in recent years due to their unique physical and chemical properties.Their exceptional mechanical strength,chemical stability,biocompatibility,and high thermal conductivity make them ideal candidates for a wide range of biomedical applications.Various formats,including nanodiamonds,diamond nanofilms,and diamond nanoneedle arrays(DNNAs),have been fabricated and used,exhibiting remarkable stability and low cytotoxicity.In particular,high-aspect-ratio and highdensity DNNAs demonstrate promising potential for live cell manipulation and analysis because of their unique combination of mechanical robustness,chemical stability,and wellforged bio−nanointerfaces.On the other hand,the chemical stability of diamond material makes fabrication and functionalization challenging,which could be improved for their wider adoption.展开更多
Heteroatomic substitution and vacancy engineering of spinel oxides can theoretically optimize the oxygen evolution reaction(OER)through charge redistribution and d-band center modification but still remain a great cha...Heteroatomic substitution and vacancy engineering of spinel oxides can theoretically optimize the oxygen evolution reaction(OER)through charge redistribution and d-band center modification but still remain a great challenge in both the preparation and catalytic mechanism.Herein,we proposed a novel and efficient Ar-plasma(P)-assisted strategy to construct heteroatom Mo-substituted and oxygen vacancies enriched hierarchical spinel Co_(3)O_(4)porous nanoneedle arrays in situ grown on carbon cloth(denoted P-Mo-Co_(3)O_(4)@CC)to improve the OER performance.Ar-plasma technology can efficiently generate vacancy sites at the surface of hydroxide,which induces the anchoring of Mo anion salts through electrostatic interaction,finally facilitating the substitution of Mo atoms and the formation of oxygen vacancies on the Co_(3)O_(4)surface.The P-Mo-Co_(3)O_(4)@CC affords a low overpotential of only 276 mV at 10 mA cm^(−2)for the OER,which is 58 mV superior to that of Mo-free Co_(3)O_(4)@CC and surpasses commercial RuO_(2)catalyst.The robust stability and satisfactory selectivity(nearly 100%Faradic efficiency)of P-Mo-Co_(3)O_(4)@CC for the OER are also demonstrated.Theoreti-cal studies demonstrate that Mo with variable valance states can efficiently regulates the atomic ratio of Co^(3+)/Co^(2+)and increases the number of oxygen vacancies,thereby inducing charge redistribution and tuning the d-band center of Co_(3)O_(4),which improve the adsorption energy of oxygen intermediates(e.g.,*OOH)on P-Mo-Co_(3)O_(4)@CC during OER.Furthermore,the two-electrode OER//HER electrolyzer equipped with P-Mo-Co_(3)O_(4)@CC as anode displays a low operation potential of 1.54 V to deliver a current density of 10 mA cm^(−2),and also exhibits good reversibility and anticurrent fluctuation ability under simulated real energy supply conditions,demonstrating the great potential of P-Mo-Co_(3)O_(4)@CC in water electrolysis.展开更多
Needles,as some of the most widely used medical devices,have been effectively applied in human disease prevention,diagnosis,treatment,and rehabilitation.Thin 1D needle can easily penetrate cells/organs by generating h...Needles,as some of the most widely used medical devices,have been effectively applied in human disease prevention,diagnosis,treatment,and rehabilitation.Thin 1D needle can easily penetrate cells/organs by generating highly localized stress with their sharp tips to achieve bioliquid sampling,biosensing,drug delivery,surgery,and other such applications.In this review,we provide an overview of multiscale needle fabrication techniques and their biomedical applications.Needles are classified as nanoneedles,microneedles and millineedles based on the needle diameter,and their fabrication techniques are highlighted.Nanoneedles bridge the inside and outside of cells,achieving intracellular electrical recording,biochemical sensing,and drug delivery.Microneedles penetrate the stratum corneum layer to detect biomarkers/bioelectricity in interstitial fluid and deliver drugs through the skin into the human circulatory system.Millineedles,including puncture,syringe,acupuncture and suture needles,are presented.Finally,conclusions and future perspectives for next-generation nano/micro/milli needles are discussed.展开更多
Anisotropic structures, nanoneedles, and nanospindles of rare earth hydroxychloride （RE（OH）2Cl） and oxychloride （REOCl） （rare earth=Eu and Tb） were synthesized. The rare earth hydroxychloride nanostructures we...Anisotropic structures, nanoneedles, and nanospindles of rare earth hydroxychloride （RE（OH）2Cl） and oxychloride （REOCl） （rare earth=Eu and Tb） were synthesized. The rare earth hydroxychloride nanostructures were formed via a thermally assisted hydrolysis of the rare-earth sesquioxide nanocrystals. The morphological evolution of the nanostructures was studied using high-resolution transmission electron microscopy and scanning electron microscopy, while the structural evolution was investigated using X-ray diffraction techniques. The thermal stability of the rare earth hydroxychlorides was investigated using thermogravimetric analysis. The rare earth oxychloride nanospindles were synthesized via a simple heat-treatment of rare earth hydroxychloride nanospindles.展开更多
Solar-driven desalination is a promising way to alleviate the freshwater shortage,while is facing challenges posed by low evaporation rates and severe salt accumulation.Herein,a high-performance twodimensional(2D) sol...Solar-driven desalination is a promising way to alleviate the freshwater shortage,while is facing challenges posed by low evaporation rates and severe salt accumulation.Herein,a high-performance twodimensional(2D) solar absorber with Co_(3)O_(4) nanoneedle arrays(Co_(3)O_(4)-NN) grown on the surface of reduced graphene oxide-coated pyrolyzed silk cloth(Co_(3)O_(4)-NN/rGO/PSC) was prepared,and a salt-free evaporator system was assembled based on the composite material and siphonage-the flowing water delivery.It is revealed that the evaporation enthalpy of water can be reduced over the 2D solar absorber grown with Co_(3)O_(4)-NN_T enabling an evaporation rate of up to 2.35 kg m^(-2) h^(-1) in DI water under one solar irradiation.The desalination process can be carried out continuously even with salt concentration up to 20 wt%,due to the timely removal of concentrated brine from the interface with the assistance of directed flowing water.Moreover,the 2D structure and the flowing water also provide an opportunity to convert waste solar heat into electricity in the evaporator based on the seebeck effect,ensuring simultaneous freshwater production and power generation.It is believed that this work provides insights into designing hybrid systems with high evaporation rate,salt resistance,and electricity generation.展开更多
Electrochemical oxidation is an effective method to degrade persistent organic pollutants.However,due to the limited catalytic activity of traditional thin film electrodes,the anodic oxidation process is slow and usua...Electrochemical oxidation is an effective method to degrade persistent organic pollutants.However,due to the limited catalytic activity of traditional thin film electrodes,the anodic oxidation process is slow and usually requires high energy consumption.Herein,Ti/SnO_(2)-Sb electrode with regulated surface structure was reported to enhance the performance for electrochemical oxidation of persistent organic pollutants.The electrode deposited with SnO_(2)-Sb nanoneedles(Ti/N-SnO_(2)-Sb)showed higher oxidation activity.Its kinetic constant for perfluorooctanoic acid(PFOA)oxidation was 2.0 h^(-1)and the total organic carbon removal rate was 81.7%(4 h)at a relatively low current density of 6 mA/cm^2.Compared with Ti/SnO_(2)-Sb thin film and nanoparticles,Ti/N-SnO_(2)-Sb significantly improved the electrochemical active area and·OH yield,and simultaneously reduced the electron transfer resistance,which enabled it to oxidize PFOA more rapidly even at a lower potential.This work provides a new strategy for promoting the electrochemical oxidation performance.展开更多
The development of low-cost,efficient,and stable electrocatalysts is critical for the anodic oxygen evolution reaction(OER).Ni_(3)S_(2) not only has the advantages of low cost,easy preparation,and environmental friend...The development of low-cost,efficient,and stable electrocatalysts is critical for the anodic oxygen evolution reaction(OER).Ni_(3)S_(2) not only has the advantages of low cost,easy preparation,and environmental friendliness,but also attracts attention for its structure throughout the Ni-Ni bond,which provides metallike electrical conductivity.In this work,the Fe and Ce double-doped Ni_(3)S_(2) nanoneedle array catalyst(Fe,Ce-Ni_(3)S_(2)@NF)was prepared by a one-step hydrothermal method.The synergistic doping of Fe and Ce optimized the microscopic morphology and the electronic structure of Ni_(3)S_(2),which increased the exposure of catalytically active sites,enhanced the electron transfer rate in the OER process,and improved the intrinsic activity of the catalyst.The catalyst has an overpotential of 254 mV at 10 mA cm^(-2) and a Tafel slope of 55.56 mV dec^(-1),and exhibits good electrocatalytic performance under alkaline conditions(1 M KOH).Compared with the original Ni_(3)S_(2)(363 mV at 10 mA cm^(-2)),the overpotential of Fe,Ce-Ni_(3)S_(2)@NF is reduced by 109 mV.This provides a new feasible direction for the preparation of transition metal and lanthanide metal double-doped catalysts and their application in electrocatalysis.展开更多
Flower-like micrometer-sized crystalline Mo fibres have been prepared by directly heating Mo powder on Mo foil, under Ar atmosphere. ED, EDX, SEM and HRTEM studies reveal that each fibre consists of a single Mo crysta...Flower-like micrometer-sized crystalline Mo fibres have been prepared by directly heating Mo powder on Mo foil, under Ar atmosphere. ED, EDX, SEM and HRTEM studies reveal that each fibre consists of a single Mo crystal containing multi-hollow cores. A one-dimensional growth mechanism, on the basis of the one-dimensional thermal flow during fibre formation, is discussed.展开更多
基金financially supported by the National Natural Science Foundation of China(No.22202151)Fundamental Research Program of Shanxi Province(No.202203021212243)the National Research Foundation,Singapore,and A*STAR(Agency for Science Technology and Research)under its LCER Phase 2 Program Hydrogen&Emerging Technologies FI,Directed Hydrogen Program(No.U2305D4003)
文摘The electrochemical conversion of nitrate,commonly found in industrial effluents and contaminated groundwater,into ammonia offers a sustainable strategy for both wastewater remediation and ammonia production.However,most existing catalysts exhibit limited activity and stability,particularly under industrial-level current density.Here we present a straightforward hydrothermalcalcination method to in situ fabricate Cu-doped Co_(3)O_(4)nanoneedle arrays on three-dimensional porous copper foam(Cu-Co_(3)O_(4)/CF).The resulting electrode delivers an industrial-sc ale current density of~1000 m A cm^(-2),a high NH_(3) yield rate of 58.4 mg h^(-1)cm^(-2),and a Faradaic efficiency of 98.3%at-0.5 V versus RHE.The outstanding performance under high current density highlights the significant practical potential of Cu-Co_(3)O_(4)/CF for large-scale applications.Density functional theory(DFT)calculations combined with experimental analysis demonstrate that Cu incorporation optimizes NO_(3)^(-)adsorption energy.More importantly,the doping of Cu accelerates the kinetics of the Volmer step(H_(2)O→*H+*OH),which provides protons for the hydrogenation pathway.This promotes the selective formation of NH3 during the electrochemical nitrate reduction reaction(NO_(3)RR).Overall,this work provides fundamental insights into designing efficient transition metal oxide catalysts for nitrate valorization.
基金the Natural Science Foundation of Liaoning Province(2023-MS-115)National Natural Science Foundation of China(52173206)CNPC Innovation Found(2020D-5007-0406)。
文摘With the sustainable and efficient development of aqueous zinc ion batteries(AZIBs),the research on addressing the issues of the adaptability and durability of zinc anodes has been hot-topic and is still of great challenge.In this work,inspired by the sand treatment and afforestation of the Gobi Beach in Northwest China to ameliorate the problem of wind and sand encroachment,we propose a material with a morphology similar to that of a“shelter forest”,CuSiO_(3)nanoneedles arrays grown on both sides of reduced graphene oxide(rGO@CuSi),as a coating layer on the zinc metal surface to guide Zn gradient deposition.The presence of rGO improves the electrical conductivity of CuSiO_(3),and the finite element simulation of the electric field and Zn^(2+)concentration proves that the electric field distribution can be effectively homogenized and the local current density can be reduced for the rGO@CuSi-Zn electrode with the surface presenting the shape of a protective forest.This is due to the abundant pores between the nano-needle array structures on the surface of the electrode,which provide high electron and ion transport paths,and are conducive to achieving uniform Zn deposition,like the principle of wind-sand stabilization by protective forest.Both electrochemical experiments and density functional theory calculations show that the negatively charged surface of r GO@CuSi with good Zn affinity is more capable of guiding Zn^(2+)transport.Thanks to its inherent material and structural characteristics,the r GO@CuSi-Zn anode has a high specific capacity and good cycling stability.This study provides insight for interface engineering like protective forest to accelerate the commercialization of high-performance Zn-based batteries.
文摘Cu-based catalysts are the most promising candidates for electrochemical CO_(2)reduction(CO_(2)RR)to multi-carbon(C_(2))products.Optimizing the C-C coupling process,the rate-determining step for C_(2)product generation,is an important strategy to improve the production and selectivity of the C_(2)products.In this study,we determined that the local electric field can promote the C-C coupling reaction and enhance CO_(2)electroreduction to C_(2)products.First,finite-element simulations indicated that the high curvature of the Cu nanoneedles results in a large local electric field on their tips.Density functional theory(DFT)calculations proved that a large electric field can promote C-C coupling.Motivated by this prediction,we prepared a series of Cu catalysts with different curvatures.The Cu nanoneedles(NNs)exhibited the largest number of curvatures,followed by the Cu nanorods(NRs),and Cu nanoparticles(NPs).The Cu NNs contained the highest concentration of adsorbed K+,which resulted in the highest local electric field on the needles.CO adsorption sensor tests indicated that the Cu NNs exhibited the strongest CO adsorption ability,and in-situ Fourier-transform infrared spectroscopy(FTIR)showed the strongest*COCO and*CO signals for the Cu NNs.These experimental results demonstrate that high-curvature nanoneedles can induce a large local electric field,thus promoting C-C coupling.As a result,the Cu NNs show a maximum FEC_(2)of 44%for CO_(2)RR at a low potential(-0.6 V vs.RHE),which is approximately 2.2 times that of the Cu NPs.This work provides an effective strategy for enhancing the production of multi-carbon products during CO_(2)RR.
基金jointly supported by the National Natural Science Foundations of China(No.51572246)the Fundamental Research Funds for the Central Universities(Nos.2652017401 and 2652015425)
文摘Bimetallic Ni–Co sulfides are outstanding pseudocapacitive materials with high electrochemical activity and excellent energy storage performance as electrodes for high-performance supercapacitors.In this study,a novel urchin-like NiCo2S4@mesocarbon microbead(NCS@MCMB) composite with a core–shell structure was prepared by a facile two-step hydrothermal method.The highly conductive MCMBs offered abundant adsorption sites for the growth of NCS nanoneedles,which allowed each nanoneedle to fully unfold without aggregation,resulting in improved NCS utilization and efficient electron/ion transferin the electrolyte.When applied as an electrode material for supercapacitors,the composite exhibited a maximum specific capacitance of 936 Fg-1 at 1 Ag-1 and a capacitance retention of 94% after 3000 cycles at 5 Ag-1,because of the synergistic effect of MCMB and NCS.Moreover,we fabricated an asymmetric supercapacitor based on the NCS@MCMB composite,which exhibited enlarged voltage windows and could power a light-emitting diode device for several minutes,further demonstrating the exceptional electrochemical performance of the NCS@MCMB composite.
基金supported by National Natural Science Foundation of China(21476097,21776118,21507046)Six Talent Peaks Project in Jiangsu Province(2014-JNHB-014)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘The suppression of the recombination of electrons and holes(e–h)and the enhancement of the light absorption of semiconductors are two key points toward efficient photocatalytic degradation.Here,we report a few-layer g-C_3N_4/α-MoO_(3)nanoneedles(flg-C_3N_4/α-MoO_(3)NNs)all-solid-state Z-scheme mechanism photocatalyst synthesized via a typical hydrothermal method in a controlled manner.The recombination of the photo-induced e–h pairs could be effectively restrained by the Z-scheme passageway between the flg-C_3N_4 andα-MoO_(3)NNs in the composite,which could also promise a high redox ability to degrade pollutants.And it became possible for the prepared photocatalyst to absorb light in a wide range of wavelengths.The detailed mechanism was studied by electron spin-resonance spectroscopy(ESR).The low-dimensional nanostructure of the two constituents(α-MoO_(3)NNs with one-dimensional structure and flg-C_3N_4 with two-dimensional structure)endowed the composite with varieties of excellent physicochemical properties,which facilitated the transfer and diffusion of the photoelectrons and increased the specific surface area and the active sites.The 10 wt%flg-C_3N_4/α-MoO_(3)NNs showed the best photocatalytic performance toward RhB degradation,the rate of which was 71.86%,~2.6 times higher than that ofα-MoO_(3)NNs.
基金This work was supported by the National Natural Science Foundation of China(20271006).
文摘Single-crystal SrCO3 nanoneedles were synthesized in reverse micelles at low temperature. The products were characterized by X-ray diffraction, X-ray energy dispersive spectrometer, transmission electron microscopy and selected area electronic diffraction. The influences of experimental conditions on the morphologies of the products were discussed. The growth mechanism of SrCO3 nanoneedles in reverse micelles were proposed.
基金supported by the international doctoral fellowship (IDF) scheme from Universiti Teknologi Malaysia
文摘A green synthesis method to produce silver nanoneedles was described using shallot and apricot tree gum（ATG）.A fast,simple,and low cost method was used to synthesize silver with nanoparticle and nanoneedle shape from the silver nitrate solution.Shallot as a reducing agent and apricot tree gum（ATG） as a stabilizer and a capping agent were utilized to reduce and form silver ions into silver atoms with needle and particle shape.Moreover,high crystalline structures of silver nanoparticles（AgNPs） with diameters of 8-20 nm and silver nanoneedles with average diameters of 50-60 nm and lengths of 5-10 μm were consequently synthesized by shallot and the mixture of shallot and ATG.A self-assembly mechanism was proposed to indicate the formation of needle-like structures of spherical Ag NPs via carbon chains of ATG.The results indicate that the presence of ATG with shallot can transfer the reduced Ag NPs into the silver nanoneedle.The findings were characterized using X-ray diffraction（XRD）,ultra violet visible（UV-Vis） spectrometry,field emission scanning electron microscopy（FESEM）,and transmission electron microscopy（TEM） techniques.
基金supported by the National Natural Science Foundation of China(31870570)the Science and Technology Plan of Fujian Provincial,China(2020H4026,2022G02020 and 2022H6002)+1 种基金the Science and Technology Plan of Xiamen(3502Z20203005)the Scientific Research Start-up Funding for Special Professor of Minjiang Scholars。
文摘Although lithium(Li)metal delivers the highest theoretical capacity as a battery anode,its high reactivity can generate Li dendrites and"dead"Li during cycling,resulting in poor reversibility and low Li utilization.Inducing uniform Li plating/stripping is the core of solving these problems.Herein,we design a highly lithiophilic carbon film with an outer sheath of the nanoneedle arrays to induce homogeneous Li plating/stripping.The excellent conductivity and 3D framework of the carbon film not only offer fast charge transport across the entire electrode but also mitigate the volume change of Li metal during cycling.The abundant lithiophilic sites ensure stable Li plating/stripping,thereby inhibiting the Li dendritic growth and"dead"Li formation.The resulting composite anode allows for stable Li stripping/plating under 0.5 mA cm^(-2) with a capacity of 0.5 mA h cm^(-2) for 4000 h and 3 mA cm^(-2) with a capacity of3 mA h cm^(-2) for 1000 h.The Ex-SEM analysis reveals that lithiophilic property is different at the bottom,top,or channel in the structu re,which can regulate a bottom-up uniform Li deposition behavior.Full cells paired with LFP show a stable capacity of 155 mA h g^(-1) under a current density of 0.5C.The pouch cell can keep powering light-emitting diode even under 180°bending,suggesting its good flexibility and great practical applications.
基金financial support from the National Natural Science Foundation of China(21878129,21477050 and 21522603)the Innovation Entrepreneurship Program of Jiangsu Province(Surencaiban[2016]32).
文摘Self-supported core–shell Co_(9)S_(8)@NiCo_(2)O_(4) hollow nanoneedle arrays are prepared on carbon fibers(CFs)through a facile two-step hydrothermal and electrodeposition method for high performance supercapacitors.Within the hybrid nanostructures,the high conductivity Co_(9)S_(8) hollow nanoneedles can act as backbones for anchoring the NiCo_(2)O_(4) nanosheets with high capacity.As a result,the hierarchical hybrid structure exhibits a high specific capacitance of 1022.5 F g^(−1) at a current density of 1 A g^(−1).Moreover,an asymmetric supercapacitor(ASC)is successfully assembled by using the core–shell Co_(9)S_(8)@NiCo_(2)O_(4) nanoneedle arrays on carbon fibers as the positive electrode and activated carbon(AC)as the negative electrode,exhibiting a high energy density of 24.85 W h kg^(−1) at a power density of 222 W kg^(−1) as well as a long-term cycling performance with 88.9%initial capacitance retention.Two ASC devices in series can power three red or white parallel LEDs.Therefore,these results suggest that this core–shell hybrid nanostructure has great potential for energy storage systems.
基金supported by initial funding for top level talents of Shenyang University of Technology and Nature Science Fund of Liaoning province(no.20170540671).
文摘In this work,mesoporous NiCo_(2)O_(4) nanoneedle arrays grown on a nickel foam substrate are fabricated by a facile hydrothermal route.The as-synthesized NiCo_(2)O_(4) products as binder-free electrodes for supercapacitors show a superior discharge areal capacity of 0.998 C cm^(-2) at a current density of 2 mA cm^(-2),excellent rate performance(60.25% retention with current density increasing from 2 mA cm^(-2) to 200 mA cm^(-2))and outstanding cycling stability(about 19.3% loss after 12000 cycles at a current density of 20 mA cm^(-2)).An assembled supercapacitor using a NiCo_(2)O_(4) electrode as the positive electrode delivers a volumetric energy density of 0.33 mW h cm^(-3) at a volumetric power density of 12 mW h cm^(-3) and still achieves 63.6% retention with the volumetric power density increasing to 120 mW h cm^(-3).Surprisingly,140.6% capacity retention is attained after 8000 cycles at 10 mA cm^(-2).
基金supported by the National Natural Science Foundation of China(51903172,52073216)the Sichuan Science and Technology Program(2022NSFSC1939).
文摘Inflammatory bowel disease(IBD)is a chronic and refractory condition characterized by disrupted epithelial barrier,dysregulated immune balance,and altered gut microbiota.Nano-enabled interventions for restoring gut homeostasis have the potential to alleviate inflammation in IBD.Herein,we developed a combination of olsalazine(Olsa)-based nanoneedles and microbiota-regulating inulin gel to reshape intestinal homeostasis and relieve inflammation.The Olsa-derived nanoneedles exhibited reactive oxygen species scavenging ability and anti-inflammatory effects in lipopolysaccharide-simulated macrophages.The composite of nanoneedles and inulin gel(Cu2(Olsa)/Gel)displayed a macroporous structure,improved bio-adhesion,and enhanced colon retention after oral administration.Mechanistically,the composite effectively downregulated pro-inflammatory cytokine levels and promoted epithelial barrier repair through anti-inflammatory and antioxidant therapies,resulting in significant alleviation of colitis in three animal models of IBD.Furthermore,analysis of gut microbiota revealed that Cu2(Olsa)/Gel treatment increased the diversity of intestinal microflora and decreased the relative abundance of pathogenic bacteria such as Proteobacteria.Overall,this study provides a self-delivering nanodrug and dietary fiber hydrogel composite for IBD therapy,offering an efficient approach to restore intestinal homeostasis.
基金This work was supported by the National Key R&D Program of China(Grant No.2021YFC2103704)the National Natural Science Foundation of China(Grant Nos.21878266 and 22078288)+1 种基金the Science and Technology Research Project of Henan Province(Grant No.222300420527)Program of Processing and Efficient Utilization of Biomass Resources of Henan Center for Outstanding Overseas Scientists(Grant No.GZS2022007).
文摘Ultra-dispersed Ni nanoparticles(7.5 nm)on nitrogen-doped carbon nanoneedles(Ni@NCNs)were prepared by simple pyrolysis of Ni-based metal–organic-framework for selective hydrogenation of halogenated nitrobenzenes to corresponding anilines.Two different crystallization methods(stirring and static)were compared and the optimal pyrolysis temperature was explored.Ni@NCNs were systematically characterized by wide analytical techniques.In the hydrogenation of p-chloronitrobenzene,Ni@NCNs-600(pyrolyzed at 600°C)exhibited extraordinarily high performance with 77.9 h^(–1)catalytic productivity and>99%p-chloroaniline selectivity at full p-chloronitrobenzene conversion under mild conditions(90°C,1.5 MPa H2),showing obvious superiority compared with reported Ni-based catalysts.Notably,the reaction smoothly proceeded at room temperature with full conversion and>99%selectivity.Moreover,Ni@NCNs-600 afforded good tolerance to various nitroarenes substituted by sensitive groups(halogen,nitrile,keto,carboxylic,etc.),and could be easily recycled by magnetic separation and reused for 5 times without deactivation.The adsorption tests showed that the preferential adsorption of–NO2 on the catalyst can restrain the dehalogenation of p-chloronitrobenzene,thus achieving high p-chloroaniline selectivity.While the high activity can be attributed to high Ni dispersion,special morphology,and rich pore structure of the catalyst.
基金supported by the National Nature Science Foundation of China(52172241,52173242,32201176,U20A20194)Hong Kong Research Grants Council(11215920,11218522,11218523,11308321,11308120)+2 种基金Guangdong Basic and Applied Basic Research Foundation(2019B1515120005)Shenzhen Science and Technology Planning Project(JCYJ20200109115424940)Science and Technology Foundation of Suzhou(ZXL2023203).
文摘CONSPECTUS:Diamond nanomaterials have attracted significant interest in recent years due to their unique physical and chemical properties.Their exceptional mechanical strength,chemical stability,biocompatibility,and high thermal conductivity make them ideal candidates for a wide range of biomedical applications.Various formats,including nanodiamonds,diamond nanofilms,and diamond nanoneedle arrays(DNNAs),have been fabricated and used,exhibiting remarkable stability and low cytotoxicity.In particular,high-aspect-ratio and highdensity DNNAs demonstrate promising potential for live cell manipulation and analysis because of their unique combination of mechanical robustness,chemical stability,and wellforged bio−nanointerfaces.On the other hand,the chemical stability of diamond material makes fabrication and functionalization challenging,which could be improved for their wider adoption.
基金National Natural Science Foundation of China,Grant/Award Numbers:21875112,22109073Natural Science Foundation of Jiangsu Province,Grant/Award Number:BK20221321。
文摘Heteroatomic substitution and vacancy engineering of spinel oxides can theoretically optimize the oxygen evolution reaction(OER)through charge redistribution and d-band center modification but still remain a great challenge in both the preparation and catalytic mechanism.Herein,we proposed a novel and efficient Ar-plasma(P)-assisted strategy to construct heteroatom Mo-substituted and oxygen vacancies enriched hierarchical spinel Co_(3)O_(4)porous nanoneedle arrays in situ grown on carbon cloth(denoted P-Mo-Co_(3)O_(4)@CC)to improve the OER performance.Ar-plasma technology can efficiently generate vacancy sites at the surface of hydroxide,which induces the anchoring of Mo anion salts through electrostatic interaction,finally facilitating the substitution of Mo atoms and the formation of oxygen vacancies on the Co_(3)O_(4)surface.The P-Mo-Co_(3)O_(4)@CC affords a low overpotential of only 276 mV at 10 mA cm^(−2)for the OER,which is 58 mV superior to that of Mo-free Co_(3)O_(4)@CC and surpasses commercial RuO_(2)catalyst.The robust stability and satisfactory selectivity(nearly 100%Faradic efficiency)of P-Mo-Co_(3)O_(4)@CC for the OER are also demonstrated.Theoreti-cal studies demonstrate that Mo with variable valance states can efficiently regulates the atomic ratio of Co^(3+)/Co^(2+)and increases the number of oxygen vacancies,thereby inducing charge redistribution and tuning the d-band center of Co_(3)O_(4),which improve the adsorption energy of oxygen intermediates(e.g.,*OOH)on P-Mo-Co_(3)O_(4)@CC during OER.Furthermore,the two-electrode OER//HER electrolyzer equipped with P-Mo-Co_(3)O_(4)@CC as anode displays a low operation potential of 1.54 V to deliver a current density of 10 mA cm^(−2),and also exhibits good reversibility and anticurrent fluctuation ability under simulated real energy supply conditions,demonstrating the great potential of P-Mo-Co_(3)O_(4)@CC in water electrolysis.
基金National Natural Science Foundation of China(Grant Nos.52175446,51975133,51975597)Guangdong Basic and Applied Basic Research Foundation(Grant Nos.2021A1515011740,2019A1515011011)Shenzhen Fundamental Research Program(Grant No.JCYJ20170818163426597).
文摘Needles,as some of the most widely used medical devices,have been effectively applied in human disease prevention,diagnosis,treatment,and rehabilitation.Thin 1D needle can easily penetrate cells/organs by generating highly localized stress with their sharp tips to achieve bioliquid sampling,biosensing,drug delivery,surgery,and other such applications.In this review,we provide an overview of multiscale needle fabrication techniques and their biomedical applications.Needles are classified as nanoneedles,microneedles and millineedles based on the needle diameter,and their fabrication techniques are highlighted.Nanoneedles bridge the inside and outside of cells,achieving intracellular electrical recording,biochemical sensing,and drug delivery.Microneedles penetrate the stratum corneum layer to detect biomarkers/bioelectricity in interstitial fluid and deliver drugs through the skin into the human circulatory system.Millineedles,including puncture,syringe,acupuncture and suture needles,are presented.Finally,conclusions and future perspectives for next-generation nano/micro/milli needles are discussed.
文摘Anisotropic structures, nanoneedles, and nanospindles of rare earth hydroxychloride （RE（OH）2Cl） and oxychloride （REOCl） （rare earth=Eu and Tb） were synthesized. The rare earth hydroxychloride nanostructures were formed via a thermally assisted hydrolysis of the rare-earth sesquioxide nanocrystals. The morphological evolution of the nanostructures was studied using high-resolution transmission electron microscopy and scanning electron microscopy, while the structural evolution was investigated using X-ray diffraction techniques. The thermal stability of the rare earth hydroxychlorides was investigated using thermogravimetric analysis. The rare earth oxychloride nanospindles were synthesized via a simple heat-treatment of rare earth hydroxychloride nanospindles.
基金the financial support from the National Natural Science Foundation of China (Grant No. 52172038, 22179017)National Key Research and Development Program of China (Nos. 2022YFB4101600, 2022YFB4101601)。
文摘Solar-driven desalination is a promising way to alleviate the freshwater shortage,while is facing challenges posed by low evaporation rates and severe salt accumulation.Herein,a high-performance twodimensional(2D) solar absorber with Co_(3)O_(4) nanoneedle arrays(Co_(3)O_(4)-NN) grown on the surface of reduced graphene oxide-coated pyrolyzed silk cloth(Co_(3)O_(4)-NN/rGO/PSC) was prepared,and a salt-free evaporator system was assembled based on the composite material and siphonage-the flowing water delivery.It is revealed that the evaporation enthalpy of water can be reduced over the 2D solar absorber grown with Co_(3)O_(4)-NN_T enabling an evaporation rate of up to 2.35 kg m^(-2) h^(-1) in DI water under one solar irradiation.The desalination process can be carried out continuously even with salt concentration up to 20 wt%,due to the timely removal of concentrated brine from the interface with the assistance of directed flowing water.Moreover,the 2D structure and the flowing water also provide an opportunity to convert waste solar heat into electricity in the evaporator based on the seebeck effect,ensuring simultaneous freshwater production and power generation.It is believed that this work provides insights into designing hybrid systems with high evaporation rate,salt resistance,and electricity generation.
基金supported by Liaoning Revitalization Talents Program(No.XLYC2007069)the National Natural Science Foundation of China(Nos.22076019 and 22222601)open project of State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(No.HC201705)。
文摘Electrochemical oxidation is an effective method to degrade persistent organic pollutants.However,due to the limited catalytic activity of traditional thin film electrodes,the anodic oxidation process is slow and usually requires high energy consumption.Herein,Ti/SnO_(2)-Sb electrode with regulated surface structure was reported to enhance the performance for electrochemical oxidation of persistent organic pollutants.The electrode deposited with SnO_(2)-Sb nanoneedles(Ti/N-SnO_(2)-Sb)showed higher oxidation activity.Its kinetic constant for perfluorooctanoic acid(PFOA)oxidation was 2.0 h^(-1)and the total organic carbon removal rate was 81.7%(4 h)at a relatively low current density of 6 mA/cm^2.Compared with Ti/SnO_(2)-Sb thin film and nanoparticles,Ti/N-SnO_(2)-Sb significantly improved the electrochemical active area and·OH yield,and simultaneously reduced the electron transfer resistance,which enabled it to oxidize PFOA more rapidly even at a lower potential.This work provides a new strategy for promoting the electrochemical oxidation performance.
基金supported by the National Natural Science Foundation of China(No.22271018,22309012,22302013)the NSF of Guangdong Province(2023A1515010554 and 2024A1515010307).
文摘The development of low-cost,efficient,and stable electrocatalysts is critical for the anodic oxygen evolution reaction(OER).Ni_(3)S_(2) not only has the advantages of low cost,easy preparation,and environmental friendliness,but also attracts attention for its structure throughout the Ni-Ni bond,which provides metallike electrical conductivity.In this work,the Fe and Ce double-doped Ni_(3)S_(2) nanoneedle array catalyst(Fe,Ce-Ni_(3)S_(2)@NF)was prepared by a one-step hydrothermal method.The synergistic doping of Fe and Ce optimized the microscopic morphology and the electronic structure of Ni_(3)S_(2),which increased the exposure of catalytically active sites,enhanced the electron transfer rate in the OER process,and improved the intrinsic activity of the catalyst.The catalyst has an overpotential of 254 mV at 10 mA cm^(-2) and a Tafel slope of 55.56 mV dec^(-1),and exhibits good electrocatalytic performance under alkaline conditions(1 M KOH).Compared with the original Ni_(3)S_(2)(363 mV at 10 mA cm^(-2)),the overpotential of Fe,Ce-Ni_(3)S_(2)@NF is reduced by 109 mV.This provides a new feasible direction for the preparation of transition metal and lanthanide metal double-doped catalysts and their application in electrocatalysis.
文摘Flower-like micrometer-sized crystalline Mo fibres have been prepared by directly heating Mo powder on Mo foil, under Ar atmosphere. ED, EDX, SEM and HRTEM studies reveal that each fibre consists of a single Mo crystal containing multi-hollow cores. A one-dimensional growth mechanism, on the basis of the one-dimensional thermal flow during fibre formation, is discussed.
