The development of efficient photocatalytic H2-evolution materials requires both rapid electron transfer and an effective interfacial catalysis reaction for H2 production. In addition to the well-known noble metals, l...The development of efficient photocatalytic H2-evolution materials requires both rapid electron transfer and an effective interfacial catalysis reaction for H2 production. In addition to the well-known noble metals, low-cost and earth-abundant non-noble metals can also act as electron- transfer mediators to modify photocatalysts. However, as almost all non-noble metals lack the interfacial catalytic active sites required for the H2-evolution reaction, the enhancement of the photocatalytic performance is limited. Therefore, the development of new interfacial active sites on metal-modified photocatalysts is of considerable importance. In this study, to enhance the photocatalytic evolution of H2 by Ni-modified TiO2, the formation of NiSx as interfacial active sites was promoted on the surface of Ni nanoparticles. Specifically, the co-modified TiO2/Ni-NiSx photocatalysts were prepared via a two-step process involving the photoinduced deposition of Ni on the TiO2 surface and the subsequent formation of NiSx on the Ni surface by a hydrothermal reaction method. It was found that the TiO2/Ni-NiSx photocatalysts exhibited enhanced photocatalytic H2-evolution activity. In particular, TiO2/Ni-NiSx(30%) showed the highest photocatalytic rate (223.74 μmol h.1), which was greater than those of TiO2, TiO2/Ni, and TiO2/NiSx by factors of 22.2, 8.0, and 2.2, respectively. The improved H2-evolution performance of TiO2/Ni-NiSx could be attributed to the excellent synergistic effect of Ni and NiSx, where Ni nanoparticles function as effective mediators to transfer electrons from the TiO2 surface and NiSx serves as interfacial active sites to capture H+ ions from solution and promote the interfacial H2-evolution reaction. The synergistic effect of the non-noble metal cocatalyst and the interfacial active sites may provide new insights for the design of highly efficient photocatalytic materials.展开更多
The microstructural evolution and inteffacial reaction of the Au/Sn/Au/Sn/Au/Sn/Au couples were investigated during annealing at 453, 523, and 543 K for up to 240 h. The Au/Sn combination formed a rapid diffusion syst...The microstructural evolution and inteffacial reaction of the Au/Sn/Au/Sn/Au/Sn/Au couples were investigated during annealing at 453, 523, and 543 K for up to 240 h. The Au/Sn combination formed a rapid diffusion system. Even in rolled Au-Sn solder, three phases, such as AuSn, AuSn2, and AuSn4, were formed. After initial annealing at 453 K, the diffusion layers of AuSn, AuSn2, and AuSn4, which were formed after rolling, expanded gradually and then fully transformed into phase （containing Sn from 10% to 18.5%, mole fraction） and 6 （AuSn） phase. As a whole, the microstmcture of the couple was stable during annealing at 453 K. The solid-state interracial reaction was much faster at 523 K than at 453 K. After annealing at 523 K for 6 h, the AuSn, AuSn2, and AuSn4 were fully transformed into the phase and phase （AuSn）. In spite of the prolonged annealing time for up to 240 h, no significant change of the interfacial microstructure occurred, and the microstructure of the couple was stable during annealing at 523 K. When annealing at 543 K, however, the interfacial of Au/Sn was transformed into solid-liquid state, and the whole couple formed a eutecfic structure rapidly, causing the solder to be brittle. The study results clearly demonstrate that the service temperature of the Au-Sn solder should be lower than 543 K.展开更多
The hydrogen evolution reaction(HER)of molybdenum disulfide(MoS_(2))is limited in alkaline and acid solution because the active sites are on the finite edge with extended basal plane remaining inert.Herein,we activate...The hydrogen evolution reaction(HER)of molybdenum disulfide(MoS_(2))is limited in alkaline and acid solution because the active sites are on the finite edge with extended basal plane remaining inert.Herein,we activated the interfacial S sites by coupling with Ru nanoparticles on the inert basal plane of MoS_(2)nanosheets.The density functional theory(DFT)calculation and experimental results show that the interfacial S electronic structure was modulated.And the results of∆G H*demonstrate that the adsorption of H on the MoS_(2)was also optimized.With the advantage of interfacial S sites activation,the Ru-MoS_(2)needs only overpotential of 110 and 98 mV to achieve 10 mA·cm^(–2)in both 0.5 M H_(2)SO_(4)and ^(1) M KOH solution,respectively.This strategy paves a new way for activating the basal plane of other transition metal sulfide electrocatalysts for improving the HER performance.展开更多
Cost-effective and stable electrocatalysts with ultra-high current densities for electrochemical oxygen evolution reaction(OER)are critical to the energy crisis and environmental pollution.Herein,we report a superaero...Cost-effective and stable electrocatalysts with ultra-high current densities for electrochemical oxygen evolution reaction(OER)are critical to the energy crisis and environmental pollution.Herein,we report a superaerophobic three dimensional(3D)heterostructured nanowrinkles of bimetallic selenides consisting of crystalline NiSe2 and NiFe2Se4 grown on NiFe alloy(NiSe2/NiFe2Se4@NiFe)prepared by a thermal selenization procedure.In this unique 3D heterostructure,numerous nanowrinkles of NiSe2/NiFe2Se4 hybrid with a thickness of ~100 nm are grown on NiFe alloy in a uniform manner.Profiting by the large active surface area and high electronic conductivity,the superaerophobic NiSe2/NiFe2Se4@NiFe heterostructure exhibits excellent electrocatalytic activity and durability towards OER in alkaline media,outputting the low potentials of 1.53 and 1.54 V to achieve ultra-high current densities of 500 and 1000 mA cm^−2,respectively,which is among the most active Ni/Fe-based selenides,and even superior to the benchmark Ir/C catalyst.The in-situ derived FeOOH and NiOOH species from NiSe2/NiFe2Se4@NiFe are deemed to be efficient active sites for OER.展开更多
The composition and evolution of interfacial species play a key role during electrocatalytic process.Unveiling the structural evolution and intermediate during catalytic process by in situ characterization can shed ne...The composition and evolution of interfacial species play a key role during electrocatalytic process.Unveiling the structural evolution and intermediate during catalytic process by in situ characterization can shed new light on the electrocatalytic reaction mechanism and develop highly efficient catalyst.However,directly probing the interfacial species is extremely difficult for most spectroscopic techniques due to complicated interfacial environment and ultra-low surface concentration.Herein,electrochemical core-shell nanoparticle enhanced Raman spectroscopy is utilized to probe the composition and evolution processes of interfacial species on Au@Pt,Au@Co,and Au@PtCo core-shell nanoparticle surfaces.The spectral evidences of interfacial intermediates including hydroxide radical(OH*),superoxide ion(O_(2)^(−)),as well as metal oxide species are directly captured by in situ Raman spectroscopy,which are further confirmed by the both isotopic experiment and density functional theory calculation.These results provide a mechanistic guideline for the rational design of highly efficient electrocatalysts.展开更多
It is generally considered that the Al3Sc nanoprecipitates are highly thermal stable,mainly due to quite slow Sc diffusion in theα-Al matrix.In this paper,we demonstrate in an Al-Cu-Sc alloy that the Cu atoms have du...It is generally considered that the Al3Sc nanoprecipitates are highly thermal stable,mainly due to quite slow Sc diffusion in theα-Al matrix.In this paper,we demonstrate in an Al-Cu-Sc alloy that the Cu atoms have dual effect on the coarsening of Al3Sc nanoprecipitates.On the one hand,the Cu atoms with high diffusivity tend to accelerate the Al3Sc coarsening,which results from the Cu-promoted Sc diffusion.On the other hand,some Cu atoms will segregate at the Al3Sc/matrix interface,which further stabilizes the Al3Sc nanoprecipitates by reducing the interfacial energy.Competition between these two effects is tailored by temperature,which rationalizes the experimental findings that the coarsening kinetics of Al3Sc nanoprecipitate is greatly boosted at 300℃-overaging while significantly suppressed at 400℃-overaging.展开更多
Searching for efficient nonprecious metal-based catalysts toward oxygen evolution reaction(OER)are of significance for seawater electrolysis.Herein,a core-shell-structured hybrid of cobalt phosphide nanowires@NiFe lay...Searching for efficient nonprecious metal-based catalysts toward oxygen evolution reaction(OER)are of significance for seawater electrolysis.Herein,a core-shell-structured hybrid of cobalt phosphide nanowires@NiFe layered double hydroxide nanosheets grown on conductive nickel foam(CoP@NiFe LDH/NF)is prepared by a feasible approach at low temperature.The charming structure can provide numerous phosphide/hydroxide heterogenous interfaces,expose abundant active sites,and boost elec-tron/mass transfer,synergistically enhancing catalytic OER activity.When employed as an electrocatalyst toward the OER,the resultant CoP@NiFe LDH/NF only requires a small overpotential of 287 mV to pro-vide 300 mA/cm^(2)current density as well as long-time durability in 1.0 mol/L KOH seawater.The regula-tion of electronic states and surface reconstruction synergistically contribute to highly efficient seawater oxidation.This work provides an opportunity to construct efficient and inexpensive electrocatalysts for hydrogen production.展开更多
Water electrolysis has attracted a lot of attention in recent years for hydrogen production.CoP has been widely investigated as a traditional electrocatalyst for hydrogen evolution reaction(HER).However,the strong bon...Water electrolysis has attracted a lot of attention in recent years for hydrogen production.CoP has been widely investigated as a traditional electrocatalyst for hydrogen evolution reaction(HER).However,the strong bond strength of P-H bond and weak chemical stability are still the key problems in affecting catalytic performance of CoP.In this work,we synthesized rambutan-like CoP@Mo-Co-O hollow microspheres as HER electrocatalyst,solving the two problems of CoP as electrocatalyst.Benefiting from the unique three-dimensional space structure and interface effect between CoP and Mo-Co-O,the synthesized CoP@Mo-Co-O shows a small overpotential of 62 mV at the current density of 10 mA cm^-2 for HER,which is much lower than the corresponding overpotential of pure CoP microspheres(117 mV).Rambutan-like CoP@Mo-Co-O hollow microspheres also show robust long-term stability and excellent cycling stability.This work provides a new method for the design and improvement of non-precious HER electrocatalysts.展开更多
All-solid-state Li metal batteries(ASSLBs)using inorganic solid electrolyte(SE)are considered promising alternatives to conventional Li-ion batteries,offering improved safety and boosted energy density.While significa...All-solid-state Li metal batteries(ASSLBs)using inorganic solid electrolyte(SE)are considered promising alternatives to conventional Li-ion batteries,offering improved safety and boosted energy density.While significant progress has been made on improving the ionic conductivity of SEs,the degradation and instability of Li metal/inorganic SE interfaces have become the critical challenges that limit the coulombic efficiency,power performance,and cycling stability of ASSLBs.Understanding the mechanisms of complex/dynamic interfacial phenomena is of great importance in addressing these issues.Herein,recent studies on identifying,understanding,and solving interfacial issues on anode side in ASSLBs are comprehensively reviewed.Typical issues at Li metal/SE interface include Li dendrite growth/propagation,SE cracking,physical contact loss,and electrochemical reactions,which lead to high interfacial resistance and cell failure.The causes of these issues relating to the chemical,physical,and mechanical properties of Li metal and SEs are systematically discussed.Furthermore,effective mitigating strategies are summarized and their effects on suppressing interfacial reactions,improving interfacial Li-ion transport,maintaining interfacial contact,and stabilizing Li plating/stripping are highlighted.The in-depth mechanistic understanding of interfacial issues and complete investigations on current solutions provide foundations and guidance for future research and development to realize practical application of high-performance ASSLB.展开更多
The growth behavior of the complex intermetallic compounds(IMCs)formed at the interface of Cu/SnPbInBiSb high entropy alloy solder joints was explored.The growth inhibition mechanism of the IMCs at the Cu/SnPbInBiSb s...The growth behavior of the complex intermetallic compounds(IMCs)formed at the interface of Cu/SnPbInBiSb high entropy alloy solder joints was explored.The growth inhibition mechanism of the IMCs at the Cu/SnPbInBiSb solid−liquid reaction interface was revealed.The results showed that the growth rate of the complex IMCs obviously decreased at the Cu/SnPbInBiSb solid−liquid reaction interface.The maximum average thickness of IMCs only reached up to 1.66μm after reflowing at 200℃for 10 min.The mechanism for the slow growth of the complex IMCs was analyzed into three aspects.Firstly,the high entropy of the liquid SnPbInBiSb alloy reduced the growth rate of the complex IMCs.Secondly,the distorted lattice of complex IMCs restrained the diffusion of Cu atoms.Lastly,the higher activation energy(40.9 kJ/mol)of Cu/SnPbInBiSb solid−liquid interfacial reaction essentially impeded the growth of the complex IMCs.展开更多
Silver‐modified semiconductor photocatalysts typically exhibit enhanced photocatalytic activitytoward the degradation of organic substances.In comparison,their hydrogen‐evolution rates arerelatively low owing to poo...Silver‐modified semiconductor photocatalysts typically exhibit enhanced photocatalytic activitytoward the degradation of organic substances.In comparison,their hydrogen‐evolution rates arerelatively low owing to poor interfacial catalytic reactions to producing hydrogen.In the presentstudy,thiocyanate anions(SCN–)as interfacial catalytic active sites were selectively adsorbed ontothe Ag surface of g‐C3N4/Ag photocatalyst to promote interfacial H2‐evolution reactions.The thiocyanate‐modified g‐C3N4/Ag(g‐C3N4/Ag‐SCN)photocatalysts were synthesized via photodepositionof metallic Ag on g‐C3N4and subsequent selective adsorption of SCN– ions on the Ag surface by animpregnation method.The resulting g‐C3N4/Ag‐SCN photocatalysts exhibited considerably higherphotocatalytic H2‐evolution activity than the g‐C3N4,g‐C3N4/Ag,and g‐C3N4/SCN photocatalysts.Furthermore,the g‐C3N4/Ag‐SCN photocatalyst displayed the highest H2‐evolution rate(3.9μmolh?1)when the concentration of the SCN– ions was adjusted to0.3mmol L?1.The H2‐evolution rateobtained was higher than those of g‐C3N4(0.15μmol h?1)and g‐C3N4/Ag(0.71μmol h?1).Consideringthe enhanced performance of g‐C3N4/Ag upon minimal addition of SCN– ions,a synergistic effectof metallic Ag and SCN– ions is proposed―the Ag nanoparticles act as an effective electron‐transfermediator for the steady capture and rapid transportation of photogenerated electrons,while theadsorbed SCN– ions serve as an interfacial active site to effectively absorb protons from solution andpromote rapid interfacial H2‐evolution reactions.Considering the present facile synthesis and itshigh efficacy,the present work may provide new insights into preparing high‐performance photocatalytic materials展开更多
Typical Q235 low-carbon steel samples with different hydrogen contents(0.0004,0.0008,and 0.0013 wt.%)were prepared by adjusting the environment humidity and moisture.The effects of hydrogen on interfacial heat transfe...Typical Q235 low-carbon steel samples with different hydrogen contents(0.0004,0.0008,and 0.0013 wt.%)were prepared by adjusting the environment humidity and moisture.The effects of hydrogen on interfacial heat transfer,contact behavior,and microstructure evolution were investigated using a novel droplet solidification technique.The results revealed that when the hydrogen content increases from 0.0004 to 0.0013 wt.%,the maximum heat flux between the molten steel and cooling substrate decreases from 8.01 to 6.19 MW/m^(2),and the total heat removed in the initial 2 s reduces from 10.30 to 8.27 MJ/m^(2).Moreover,the final contact angle between the molten steel and substrate increases from 103.741°to 113.697°,and the number of pores on the droplet bottom surface increases significantly from 21 to 210 with the increase in hydrogen.The surface roughness of the droplet bottom surface increases from 20.902 to 49.181 pm.In addition,the average grain size of the droplet increases from 14.778 to 33.548 pm with the increase in the hydrogen content.The interfacial contact condition becomes worse due to the escape of hydrogen from the steel matrix during the cooling process,which leads to the reduction in the interfacial heat transfer and the increase in the grain size.展开更多
Nickel molybdate(NiMoO_(4))attracts superior hydrogen desorption behavior but noticeably poor for efficiently driving the hydrogen evolution reaction(HER)in alkaline media due to the sluggish water dissociation step.H...Nickel molybdate(NiMoO_(4))attracts superior hydrogen desorption behavior but noticeably poor for efficiently driving the hydrogen evolution reaction(HER)in alkaline media due to the sluggish water dissociation step.Herein,we successfully accelerate the water dissociation kinetics of NiMoO_(4)for prominent HER catalytic properties via simultaneous in situ interfacial engineering with molybdenum dioxide(MoO_(2))and doping with phosphorus(P).The as-synthesized P-doped NiMoO_(4)/MoO_(2)heterostructure nanorods exhibit outstanding HER performance with an extraordinary low overpotential of-23 m V at a current density of 10 m A cm^(-2),which is highly comparable to the performance of the state-of-art Pt/C coated on nickel foam(NF)catalyst.The density functional theory(DFT)analysis reveals the enhanced performance is attributed to the formation of MoO_(2)during the in situ epitaxial growth that substantially reduces the energy barrier of the Volmer pathway,and the introduction of P that provides efficient hydrogen desorption of Ni MoO_(2).This present work creates valuable insight into the utilization of interfacial and doping systems for hydrogen evolution catalysis and beyond.展开更多
Interfacial water molecules are the most important participants in the hydrogen evolution reaction(HER).Hence,understanding the behavior and role that interfacial water plays will ultimately reveal the HER mechanism.U...Interfacial water molecules are the most important participants in the hydrogen evolution reaction(HER).Hence,understanding the behavior and role that interfacial water plays will ultimately reveal the HER mechanism.Unfortunately,investigating interfacial water is extremely challenging owing to the interference caused by bulk water molecules and complexity of the interfacial environment.Here,the behaviors of interfacial water in different cationic electrolytes on Pd surfaces were investigated by the electrochemistry,in situ core-shell nanostructure enhanced Raman spectroscopy and theoretical simulation techniques.Direct spectral evidence reveals a red shift in the frequency and a decrease in the intensity of interfacial water as the potential is shifted in the positively direction.When comparing the different cation electrolyte systems at a given potential,the frequency of the interfacial water peak increases in the specified order:Li+<Na^(+)<K^(+)<Ca^(2+)<Sr^(2+).The structure of interfacial water was optimized by adjusting the radius,valence,and concentration of cation to form the two-H down structure.This unique interfacial water structure will improve the charge transfer efficiency between the water and electrode further enhancing the HER performance.Therefore,local cation tuning strategies can be used to improve the HER performance by optimizing the interfacial water structure.展开更多
基金supported by the National Natural Science Foundation of China(21477094)the Fundamental Research Funds for the Central Universities(WUT 2017IB002)~~
文摘The development of efficient photocatalytic H2-evolution materials requires both rapid electron transfer and an effective interfacial catalysis reaction for H2 production. In addition to the well-known noble metals, low-cost and earth-abundant non-noble metals can also act as electron- transfer mediators to modify photocatalysts. However, as almost all non-noble metals lack the interfacial catalytic active sites required for the H2-evolution reaction, the enhancement of the photocatalytic performance is limited. Therefore, the development of new interfacial active sites on metal-modified photocatalysts is of considerable importance. In this study, to enhance the photocatalytic evolution of H2 by Ni-modified TiO2, the formation of NiSx as interfacial active sites was promoted on the surface of Ni nanoparticles. Specifically, the co-modified TiO2/Ni-NiSx photocatalysts were prepared via a two-step process involving the photoinduced deposition of Ni on the TiO2 surface and the subsequent formation of NiSx on the Ni surface by a hydrothermal reaction method. It was found that the TiO2/Ni-NiSx photocatalysts exhibited enhanced photocatalytic H2-evolution activity. In particular, TiO2/Ni-NiSx(30%) showed the highest photocatalytic rate (223.74 μmol h.1), which was greater than those of TiO2, TiO2/Ni, and TiO2/NiSx by factors of 22.2, 8.0, and 2.2, respectively. The improved H2-evolution performance of TiO2/Ni-NiSx could be attributed to the excellent synergistic effect of Ni and NiSx, where Ni nanoparticles function as effective mediators to transfer electrons from the TiO2 surface and NiSx serves as interfacial active sites to capture H+ ions from solution and promote the interfacial H2-evolution reaction. The synergistic effect of the non-noble metal cocatalyst and the interfacial active sites may provide new insights for the design of highly efficient photocatalytic materials.
文摘The microstructural evolution and inteffacial reaction of the Au/Sn/Au/Sn/Au/Sn/Au couples were investigated during annealing at 453, 523, and 543 K for up to 240 h. The Au/Sn combination formed a rapid diffusion system. Even in rolled Au-Sn solder, three phases, such as AuSn, AuSn2, and AuSn4, were formed. After initial annealing at 453 K, the diffusion layers of AuSn, AuSn2, and AuSn4, which were formed after rolling, expanded gradually and then fully transformed into phase （containing Sn from 10% to 18.5%, mole fraction） and 6 （AuSn） phase. As a whole, the microstmcture of the couple was stable during annealing at 453 K. The solid-state interracial reaction was much faster at 523 K than at 453 K. After annealing at 523 K for 6 h, the AuSn, AuSn2, and AuSn4 were fully transformed into the phase and phase （AuSn）. In spite of the prolonged annealing time for up to 240 h, no significant change of the interfacial microstructure occurred, and the microstructure of the couple was stable during annealing at 523 K. When annealing at 543 K, however, the interfacial of Au/Sn was transformed into solid-liquid state, and the whole couple formed a eutecfic structure rapidly, causing the solder to be brittle. The study results clearly demonstrate that the service temperature of the Au-Sn solder should be lower than 543 K.
基金the National Natural Science Foundation of China(Nos.51871078 and 52071119)Heilongjiang Science Foundation(No.E201808).
文摘The hydrogen evolution reaction(HER)of molybdenum disulfide(MoS_(2))is limited in alkaline and acid solution because the active sites are on the finite edge with extended basal plane remaining inert.Herein,we activated the interfacial S sites by coupling with Ru nanoparticles on the inert basal plane of MoS_(2)nanosheets.The density functional theory(DFT)calculation and experimental results show that the interfacial S electronic structure was modulated.And the results of∆G H*demonstrate that the adsorption of H on the MoS_(2)was also optimized.With the advantage of interfacial S sites activation,the Ru-MoS_(2)needs only overpotential of 110 and 98 mV to achieve 10 mA·cm^(–2)in both 0.5 M H_(2)SO_(4)and ^(1) M KOH solution,respectively.This strategy paves a new way for activating the basal plane of other transition metal sulfide electrocatalysts for improving the HER performance.
基金financially supported by the National Natural Science Foundation of China(21922811,51702284,and 21878270)Zhejiang Provincial Natural Science Foundation of China(LR19B060002)the Startup Foundation for Hundred-Talent Program of Zhejiang University.
文摘Cost-effective and stable electrocatalysts with ultra-high current densities for electrochemical oxygen evolution reaction(OER)are critical to the energy crisis and environmental pollution.Herein,we report a superaerophobic three dimensional(3D)heterostructured nanowrinkles of bimetallic selenides consisting of crystalline NiSe2 and NiFe2Se4 grown on NiFe alloy(NiSe2/NiFe2Se4@NiFe)prepared by a thermal selenization procedure.In this unique 3D heterostructure,numerous nanowrinkles of NiSe2/NiFe2Se4 hybrid with a thickness of ~100 nm are grown on NiFe alloy in a uniform manner.Profiting by the large active surface area and high electronic conductivity,the superaerophobic NiSe2/NiFe2Se4@NiFe heterostructure exhibits excellent electrocatalytic activity and durability towards OER in alkaline media,outputting the low potentials of 1.53 and 1.54 V to achieve ultra-high current densities of 500 and 1000 mA cm^−2,respectively,which is among the most active Ni/Fe-based selenides,and even superior to the benchmark Ir/C catalyst.The in-situ derived FeOOH and NiOOH species from NiSe2/NiFe2Se4@NiFe are deemed to be efficient active sites for OER.
基金the National Key Research and Development Program of China(No.2020YFB1505800)the National Natural Science Foundation of China(Nos.21925404 and 22021001)+5 种基金the Shenzhen Science and Technology Research Grant(No.JCYJ20200109140416788)the Science and Technology Program of Fujian Province(No.2021Y01010295)the Youth Talent Support Program of Fujian Province(Eyas Plan of Fujian Province 2021)Research Initiation Fund of Jimei University(No.ZQ2021008)the Natural Science Foundation of Fujian Province of China(No.2021J06001)the China Postdoctoral Science Foundation(Nos.2021TQ0188 and 2021M691874).
文摘The composition and evolution of interfacial species play a key role during electrocatalytic process.Unveiling the structural evolution and intermediate during catalytic process by in situ characterization can shed new light on the electrocatalytic reaction mechanism and develop highly efficient catalyst.However,directly probing the interfacial species is extremely difficult for most spectroscopic techniques due to complicated interfacial environment and ultra-low surface concentration.Herein,electrochemical core-shell nanoparticle enhanced Raman spectroscopy is utilized to probe the composition and evolution processes of interfacial species on Au@Pt,Au@Co,and Au@PtCo core-shell nanoparticle surfaces.The spectral evidences of interfacial intermediates including hydroxide radical(OH*),superoxide ion(O_(2)^(−)),as well as metal oxide species are directly captured by in situ Raman spectroscopy,which are further confirmed by the both isotopic experiment and density functional theory calculation.These results provide a mechanistic guideline for the rational design of highly efficient electrocatalysts.
基金financially supported by the National Natural Science Foundation of China(Nos.51621063,51625103,51722104,51790482,51761135031 and 51871033)the National Key Research and Development Program of China(No.2016YFB0700403)+1 种基金the 111 Project of China(No.BP2018008)supported by the International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies.
文摘It is generally considered that the Al3Sc nanoprecipitates are highly thermal stable,mainly due to quite slow Sc diffusion in theα-Al matrix.In this paper,we demonstrate in an Al-Cu-Sc alloy that the Cu atoms have dual effect on the coarsening of Al3Sc nanoprecipitates.On the one hand,the Cu atoms with high diffusivity tend to accelerate the Al3Sc coarsening,which results from the Cu-promoted Sc diffusion.On the other hand,some Cu atoms will segregate at the Al3Sc/matrix interface,which further stabilizes the Al3Sc nanoprecipitates by reducing the interfacial energy.Competition between these two effects is tailored by temperature,which rationalizes the experimental findings that the coarsening kinetics of Al3Sc nanoprecipitate is greatly boosted at 300℃-overaging while significantly suppressed at 400℃-overaging.
基金Financial support from the National Natural Science Foundation of China (No.21971086)University Feature Laboratory for Energy Conversion and Nanocatalysis of Shandong Province
文摘Searching for efficient nonprecious metal-based catalysts toward oxygen evolution reaction(OER)are of significance for seawater electrolysis.Herein,a core-shell-structured hybrid of cobalt phosphide nanowires@NiFe layered double hydroxide nanosheets grown on conductive nickel foam(CoP@NiFe LDH/NF)is prepared by a feasible approach at low temperature.The charming structure can provide numerous phosphide/hydroxide heterogenous interfaces,expose abundant active sites,and boost elec-tron/mass transfer,synergistically enhancing catalytic OER activity.When employed as an electrocatalyst toward the OER,the resultant CoP@NiFe LDH/NF only requires a small overpotential of 287 mV to pro-vide 300 mA/cm^(2)current density as well as long-time durability in 1.0 mol/L KOH seawater.The regula-tion of electronic states and surface reconstruction synergistically contribute to highly efficient seawater oxidation.This work provides an opportunity to construct efficient and inexpensive electrocatalysts for hydrogen production.
文摘Water electrolysis has attracted a lot of attention in recent years for hydrogen production.CoP has been widely investigated as a traditional electrocatalyst for hydrogen evolution reaction(HER).However,the strong bond strength of P-H bond and weak chemical stability are still the key problems in affecting catalytic performance of CoP.In this work,we synthesized rambutan-like CoP@Mo-Co-O hollow microspheres as HER electrocatalyst,solving the two problems of CoP as electrocatalyst.Benefiting from the unique three-dimensional space structure and interface effect between CoP and Mo-Co-O,the synthesized CoP@Mo-Co-O shows a small overpotential of 62 mV at the current density of 10 mA cm^-2 for HER,which is much lower than the corresponding overpotential of pure CoP microspheres(117 mV).Rambutan-like CoP@Mo-Co-O hollow microspheres also show robust long-term stability and excellent cycling stability.This work provides a new method for the design and improvement of non-precious HER electrocatalysts.
基金supported by the Outstanding Youth Fund Project by the Department of Science and Technology of Jiangsu Province(Grant No.BK20220045)the Key R&D Project funded by the Department of Science and Technology of Jiangsu Province(Grant No.BE2020003)+6 种基金Key Program-Automobile Joint Fund of National Natural Science Foundation of China(Grant No.U1964205)General Program of National Natural Science Foundation of China(Grant No.51972334)General Program of National Natural Science Foundation of Beijing(Grant No.2202058)Cultivation project of leading innovative experts in Changzhou City(CQ20210003)National Overseas High-level Expert recruitment Program(Grant No.E1JF021E11)Talent Program of Chinese Academy of Sciences,“Scientist Studio Program Funding”from Yangtze River Delta Physics Research Center,and Tianmu Lake Institute of Advanced Energy Storage Technologies(Grant No.TIESSS0001)Science and Technology Research Institute of China Three Gorges Corporation(Grant No.202103402)
文摘All-solid-state Li metal batteries(ASSLBs)using inorganic solid electrolyte(SE)are considered promising alternatives to conventional Li-ion batteries,offering improved safety and boosted energy density.While significant progress has been made on improving the ionic conductivity of SEs,the degradation and instability of Li metal/inorganic SE interfaces have become the critical challenges that limit the coulombic efficiency,power performance,and cycling stability of ASSLBs.Understanding the mechanisms of complex/dynamic interfacial phenomena is of great importance in addressing these issues.Herein,recent studies on identifying,understanding,and solving interfacial issues on anode side in ASSLBs are comprehensively reviewed.Typical issues at Li metal/SE interface include Li dendrite growth/propagation,SE cracking,physical contact loss,and electrochemical reactions,which lead to high interfacial resistance and cell failure.The causes of these issues relating to the chemical,physical,and mechanical properties of Li metal and SEs are systematically discussed.Furthermore,effective mitigating strategies are summarized and their effects on suppressing interfacial reactions,improving interfacial Li-ion transport,maintaining interfacial contact,and stabilizing Li plating/stripping are highlighted.The in-depth mechanistic understanding of interfacial issues and complete investigations on current solutions provide foundations and guidance for future research and development to realize practical application of high-performance ASSLB.
基金supported by the National Natural Science Foundation of China (No.U2241223)the Heilongjiang Touyan Innovation Team Program,China (No.HITTY-20190013)the Fundamental Research Funds for the Central Universities,China (No.AUEA5770400622)。
文摘The growth behavior of the complex intermetallic compounds(IMCs)formed at the interface of Cu/SnPbInBiSb high entropy alloy solder joints was explored.The growth inhibition mechanism of the IMCs at the Cu/SnPbInBiSb solid−liquid reaction interface was revealed.The results showed that the growth rate of the complex IMCs obviously decreased at the Cu/SnPbInBiSb solid−liquid reaction interface.The maximum average thickness of IMCs only reached up to 1.66μm after reflowing at 200℃for 10 min.The mechanism for the slow growth of the complex IMCs was analyzed into three aspects.Firstly,the high entropy of the liquid SnPbInBiSb alloy reduced the growth rate of the complex IMCs.Secondly,the distorted lattice of complex IMCs restrained the diffusion of Cu atoms.Lastly,the higher activation energy(40.9 kJ/mol)of Cu/SnPbInBiSb solid−liquid interfacial reaction essentially impeded the growth of the complex IMCs.
基金supported by the National Natural Science Foundation of China(51472192,21477094,21771142)the Fundamental Research Funds for the Central Universities(WUT 2017IB002)~~
文摘Silver‐modified semiconductor photocatalysts typically exhibit enhanced photocatalytic activitytoward the degradation of organic substances.In comparison,their hydrogen‐evolution rates arerelatively low owing to poor interfacial catalytic reactions to producing hydrogen.In the presentstudy,thiocyanate anions(SCN–)as interfacial catalytic active sites were selectively adsorbed ontothe Ag surface of g‐C3N4/Ag photocatalyst to promote interfacial H2‐evolution reactions.The thiocyanate‐modified g‐C3N4/Ag(g‐C3N4/Ag‐SCN)photocatalysts were synthesized via photodepositionof metallic Ag on g‐C3N4and subsequent selective adsorption of SCN– ions on the Ag surface by animpregnation method.The resulting g‐C3N4/Ag‐SCN photocatalysts exhibited considerably higherphotocatalytic H2‐evolution activity than the g‐C3N4,g‐C3N4/Ag,and g‐C3N4/SCN photocatalysts.Furthermore,the g‐C3N4/Ag‐SCN photocatalyst displayed the highest H2‐evolution rate(3.9μmolh?1)when the concentration of the SCN– ions was adjusted to0.3mmol L?1.The H2‐evolution rateobtained was higher than those of g‐C3N4(0.15μmol h?1)and g‐C3N4/Ag(0.71μmol h?1).Consideringthe enhanced performance of g‐C3N4/Ag upon minimal addition of SCN– ions,a synergistic effectof metallic Ag and SCN– ions is proposed―the Ag nanoparticles act as an effective electron‐transfermediator for the steady capture and rapid transportation of photogenerated electrons,while theadsorbed SCN– ions serve as an interfacial active site to effectively absorb protons from solution andpromote rapid interfacial H2‐evolution reactions.Considering the present facile synthesis and itshigh efficacy,the present work may provide new insights into preparing high‐performance photocatalytic materials
基金The financial support for this work from the National Natural Science Foundation of China(52274342,52130408)the Hunan Scientific Technology Projects(Grant No.2020WK2003)+1 种基金the Natural Science Foundation of Hunan Province(2021JJ40731)the Postgraduate Scientific Research Innovation Project of Hunan Province(CX20220099)is gratefully acknowledged.
文摘Typical Q235 low-carbon steel samples with different hydrogen contents(0.0004,0.0008,and 0.0013 wt.%)were prepared by adjusting the environment humidity and moisture.The effects of hydrogen on interfacial heat transfer,contact behavior,and microstructure evolution were investigated using a novel droplet solidification technique.The results revealed that when the hydrogen content increases from 0.0004 to 0.0013 wt.%,the maximum heat flux between the molten steel and cooling substrate decreases from 8.01 to 6.19 MW/m^(2),and the total heat removed in the initial 2 s reduces from 10.30 to 8.27 MJ/m^(2).Moreover,the final contact angle between the molten steel and substrate increases from 103.741°to 113.697°,and the number of pores on the droplet bottom surface increases significantly from 21 to 210 with the increase in hydrogen.The surface roughness of the droplet bottom surface increases from 20.902 to 49.181 pm.In addition,the average grain size of the droplet increases from 14.778 to 33.548 pm with the increase in the hydrogen content.The interfacial contact condition becomes worse due to the escape of hydrogen from the steel matrix during the cooling process,which leads to the reduction in the interfacial heat transfer and the increase in the grain size.
基金supported by the National Natural Science Foundation of China(21875292 and 51902103)Hunan Provincial Natural Science Foundation(2019JJ50037 and 2021JJ30087)+1 种基金Natural Science Foundation of Guangdong Province(2020A1515010798)the Hunan Joint International Laboratory of Advanced Materials and Technology for Clean Energy(2020CB1007)。
文摘Nickel molybdate(NiMoO_(4))attracts superior hydrogen desorption behavior but noticeably poor for efficiently driving the hydrogen evolution reaction(HER)in alkaline media due to the sluggish water dissociation step.Herein,we successfully accelerate the water dissociation kinetics of NiMoO_(4)for prominent HER catalytic properties via simultaneous in situ interfacial engineering with molybdenum dioxide(MoO_(2))and doping with phosphorus(P).The as-synthesized P-doped NiMoO_(4)/MoO_(2)heterostructure nanorods exhibit outstanding HER performance with an extraordinary low overpotential of-23 m V at a current density of 10 m A cm^(-2),which is highly comparable to the performance of the state-of-art Pt/C coated on nickel foam(NF)catalyst.The density functional theory(DFT)analysis reveals the enhanced performance is attributed to the formation of MoO_(2)during the in situ epitaxial growth that substantially reduces the energy barrier of the Volmer pathway,and the introduction of P that provides efficient hydrogen desorption of Ni MoO_(2).This present work creates valuable insight into the utilization of interfacial and doping systems for hydrogen evolution catalysis and beyond.
基金the National Key Research and Development Program of China(2019YFA0705400)the National Natural Science Foundation of China(T2293692,21925404,22021001,21991151,and 22002036)+1 种基金the Natural Science Foundation of Fujian Province of China(2021J06001)the National Natural Science Foundation of Henan province(232300421081).
文摘Interfacial water molecules are the most important participants in the hydrogen evolution reaction(HER).Hence,understanding the behavior and role that interfacial water plays will ultimately reveal the HER mechanism.Unfortunately,investigating interfacial water is extremely challenging owing to the interference caused by bulk water molecules and complexity of the interfacial environment.Here,the behaviors of interfacial water in different cationic electrolytes on Pd surfaces were investigated by the electrochemistry,in situ core-shell nanostructure enhanced Raman spectroscopy and theoretical simulation techniques.Direct spectral evidence reveals a red shift in the frequency and a decrease in the intensity of interfacial water as the potential is shifted in the positively direction.When comparing the different cation electrolyte systems at a given potential,the frequency of the interfacial water peak increases in the specified order:Li+<Na^(+)<K^(+)<Ca^(2+)<Sr^(2+).The structure of interfacial water was optimized by adjusting the radius,valence,and concentration of cation to form the two-H down structure.This unique interfacial water structure will improve the charge transfer efficiency between the water and electrode further enhancing the HER performance.Therefore,local cation tuning strategies can be used to improve the HER performance by optimizing the interfacial water structure.
