The reaction rate constant is a crucial kinetic parameter that governs the charge and discharge performance of batteries,particularly in high-rate and thick-electrode applications.However,conventional estimation or fi...The reaction rate constant is a crucial kinetic parameter that governs the charge and discharge performance of batteries,particularly in high-rate and thick-electrode applications.However,conventional estimation or fitting methods often overestimate the charge transfer overpotential,leading to substantial errors in reaction rate constant measurements.These inaccuracies hinder the accurate prediction of voltage profiles and overall cell performance.In this study,we propose the characteristic time-decomposed overpotential(CTDO)method,which employs a single-layer particle electrode(SLPE)structure to eliminate interference overpotentials.By leveraging the distribution of relaxation times(DRT),our method effectively isolates the characteristic time of the charge transfer process,enabling a more precise determination of the reaction rate constant.Simulation results indicate that our approach reduces measurement errors to below 2%,closely aligning with theoretical values.Furthermore,experimental validation demonstrates an 80% reduction in error compared to the conventional galvanostatic intermittent titration technique(GITT)method.Overall,this study provides a novel voltage-based approach for determining the reaction rate constant,enhancing the applicability of theoretical analysis in electrode structural design and facilitating rapid battery optimization.展开更多
The lithium-oxygen battery(LOB)is a promising source of green energy due to its energy density.However,the development of this technology is limited by the insoluble discharge product it produces.In this work,a cathod...The lithium-oxygen battery(LOB)is a promising source of green energy due to its energy density.However,the development of this technology is limited by the insoluble discharge product it produces.In this work,a cathode material with a p-n heterostructure of polyaniline(PANI)/ZnS is prepared to trap visible light,utilizing a ZnS quantum dot(ZnS QD)network to form a large number of photogenerated electron–hole pairs,thus promoting the generation and decomposition of Li_(2)O_(2).The prepared PANI/ZnS has an ultra-low overpotential of 0.06 V under illumination.Furthermore,density functional theory theoretical calculation has demonstrated the ability of the heterostructures to adsorb oxygen-containing intermediates,which not only facilitates the growth of Li_(2)O_(2),but also reduces the reaction energy required to decompose Li_(2)O_(2).The present work provides a solution to the problem of insolubility of discharge products in photo-assisted LOB.展开更多
It is well known that transition metal sulfides(TMS)(i.e.,NiS_(2))undergo electrochemical reconstructions to generate highly active Ni_(3)S_(2) during the process of hydrogen evolution reaction(HER)under overpotential...It is well known that transition metal sulfides(TMS)(i.e.,NiS_(2))undergo electrochemical reconstructions to generate highly active Ni_(3)S_(2) during the process of hydrogen evolution reaction(HER)under overpotentials of<500 mV.However,at higher overpotentials,Ni_(3)S_(2) can theoretically be further restructured into Ni and thus form Ni/Ni_(3)S_(2) heterogeneous interface structures,which may provide opportunities to further enhance HER activity of NiS_(2).Here,we selected NiS_(2) as a model electrocatalyst and investigated the influence of the reconstruction results induced from regular to ultrahigh overpotentials on its electrocatalytic hydrogen precipitation performance.The experimental results showed that the most significant enhancement of hydrogen precipitation performance was obtained for the NiS_(2)@CC-900(900 means 900 mV overpotential)sample after the ultra-high overpotential induced reconstruction.Compared with the initial overpotential of 161 mV(10 mA cm^(-2)),the overpotential of the reconstructed sample reduced by 67 mV(42%).The characterization results showed that an ultra-high overpotential of 900 mV induced deep reconstruction of NiS_(2),formed highly reactive Ni/Ni_(3)S_(2) heterogeneous interfaces,which is more conducive to improved HER performance and match well with theoretical calculations results.We demonstrated ultrahigh overpotential was an effective strategy to induce NiS_(2) deeply reconstruction and significantly improve its HER performance,and this strategy was also applicable to CoS_(2) and FeS_(2).This study provides an extremely simple and universal pathway for the reasonable construction of efficient electrocatalysts by induced TMS deeply reconstruction.展开更多
Dendrite formation severely compromises further development of zinc ion batteries. Increasing the nucleation overpotential plays a crucial role in achieving uniform deposition of metal ions. However, this strategy has...Dendrite formation severely compromises further development of zinc ion batteries. Increasing the nucleation overpotential plays a crucial role in achieving uniform deposition of metal ions. However, this strategy has not yet attracted enough attention from researchers to our knowledge. Here, we propose that thermodynamic nucleation overpotential of Zn deposition can be boosted through complexing agent and select sodium L-tartrate(Na-L) as example. Theoretical and experimental characterization reveals L-tartrate anion can partially replace H_(2)O in the solvation sheath of Zn^(2+), increasing de-solvation energy. Concurrently, the Na^(+) could absorb on the surface of Zn anode preferentially to inhibit the deposition of Zn^(2+) aggregation. In consequence, the overpotential of Zn deposition could increase from 32.2 to 45.1 mV with the help of Na-L. The Zn-Zn cell could achieve a Zn utilization rate of 80% at areal capacity of 20 mAh cm^(-2). Zn-LiMn_(2)O_(4) full cell with Na-L additive delivers improved stability than that with blank electrolyte. This study also provides insight into the regulation of nucleation overpotential to achieve homogeneous Zn deposition.展开更多
Achieving low charge overpotentials represents one of the most critical challenges for pursuing highperformance lithium-oxygen(Li-O_(2))batteries.Herein,we propose a strategy to realize low charge overpotentials by co...Achieving low charge overpotentials represents one of the most critical challenges for pursuing highperformance lithium-oxygen(Li-O_(2))batteries.Herein,we propose a strategy to realize low charge overpotentials by confining the growth of lithium peroxide(Li_(2)O_(2))inside mesoporous channels of cathodes(CMK-8).The CMK-8 cathode with tortuous pore structures can extend the diffusion distance of lithium superoxide(LiO_(2))in the mesoporous channels,facilitating the further reduction of LiO_(2) to lithium peroxide(Li_(2)O_(2))inside the pores and preventing them to be diffused out of the pores.Therefore,Li_(2)O_(2) is trapped in the mesoporous channels of CMK-8 cathodes,ensuring a good Li_(2)O_(2)/CMK-8 contact interface.The CMK-8 electrode exhibits a low charge overpotential of 0.43 V and a good cycle life for 72 cycles with a fixed capacity of 500 m Ah g^(-1) at 0.1 A g^(-1).This study proposes a strategy to achieve a low charge overpotential by confining Li_(2)O_(2) growth in the mesoporous channels of cathodes.展开更多
Generating sufficient strains on metal surfaces are highly challenging owing to that most metals can deform plastically to relax the strains on the surfaces.In this work,we developed a facile but highly efficient stac...Generating sufficient strains on metal surfaces are highly challenging owing to that most metals can deform plastically to relax the strains on the surfaces.In this work,we developed a facile but highly efficient stacked deposition strategy to in situ activation and reconstruction of NiO/NiOOH on Ni matrix,following with the migration of Fe ions to NiOOH.The Fe sites on the Ni/NiO/NiOOH facilitate the formation of the stable*OH oxygenated intermediates,and the Ni matrix in the catalyst provides the catalyst excellent stability.The oxygen evolution reaction(OER)performance of the stacked NiFe-5 with compressive strain displays the strengthened binding to oxygenated intermediates and superior OER activity,the ultralow overpotentials of 162 versus reversible hydrogen electrode at 10 mA cm^(-2).On the other hand,the Ni-5 without the incorporation of Fe has shown an outstanding hydrogen evolution reaction(HER)activity,affording an overpotential of 47 mV at 10 mA cm^(-2).The NiFe-5‖Ni-5 enables the overall water splitting at a voltage of 1.508 V to achieve 20 mA cm^(-2) with remarkable durability.The stacked deposition strategy improves binding strength of Ni-based catalysts to oxygenated intermediates via generating compressive strain,causing high catalytic activities on OER and HER.展开更多
Dendrite growth is one of the main challenges in maintaining the service life of all-solid-state lithium-ion batteries.Mechanical stress has been reported to significantly affect dendrite growth.In this study,to expla...Dendrite growth is one of the main challenges in maintaining the service life of all-solid-state lithium-ion batteries.Mechanical stress has been reported to significantly affect dendrite growth.In this study,to explain the effect of mechanical stress on electrochemical reactions in all-solid-state batteries,a modified phase-field model for dendrite growth is proposed by considering the stress-dependent overpotential.Dendrite growth under different mechanical loadings in an all-solid-state battery is investigated using the proposed model.Consistent with previous experimental results,the current result shows that compressive stress inhibits dendrite growth.Considering the stress concentration at the tips of processing-induced microcracks,the effects of the number and distribution of microcracks on dendrite growth are investigated.The results show that the stress-concentration field induced at the tips of cracks or voids can change the morphology of dendrites and decrease their growth rates.This study provides a new perspective for explaining Li dendrite growth under mechanical stress and offers inspiration for prolonging the service life of all-solid-state batteries based on defect and stress regulation,which may be further realized in experiments by filling solid electrolytes with different types of nanofillers.展开更多
The realization of high‐efficiency,reversible,stable,and safe Li‐O2 batteries is severely hindered by the large overpotential and side reactions,especially at high rate conditions.Therefore,rational design of cathod...The realization of high‐efficiency,reversible,stable,and safe Li‐O2 batteries is severely hindered by the large overpotential and side reactions,especially at high rate conditions.Therefore,rational design of cathode catalysts with high activity and stability is crucial to overcome the terrible issues at high current density.Herein,we report a surface engineering strategy to adjust the surface electron structure of boron(B)‐doped PtNi nanoalloy on carbon nanotubes(PtNiB@CNTs)as an efficient bifunctional cathodic catalyst for high‐rate and long‐life Li‐O2 batteries.Notably,the Li‐O2 batteries assembled with as‐prepared PtNiB@CNT catalyst exhibit ultrahigh discharge capacity of 20510 mA·h/g and extremely low overpotential of 0.48 V at a high current density of 1000 mA/g,both of which outperform the most reported Pt‐based catalysts recently.Meanwhile,our Li‐O2 batteries offer excellent rate capability and ultra‐long cycling life of up to 210 cycles at 1000 mA/g under a fixed capacity of 1000 mA·h/g,which is two times longer than those of Pt@CNTs and PtNi@CNTs.Furthermore,it is revealed that surface engineering of PtNi nanoalloy via B doping can efficiently tailor the electron structure of nanoalloy and optimize the adsorption of oxygen species,consequently delivering excellent Li‐O2 battery performance.Therefore,this strategy of regulating the nanoalloy by doping nonmetallic elements will pave an avenue for the design of high‐performance catalysts for metal‐oxygen batteries.展开更多
The oxygen evolution reaction(OER)is a key process in water splitting for hydrogen production,yet its sluggish kinetics pose significant challenges for catalyst development.In this work,we present the first systematic...The oxygen evolution reaction(OER)is a key process in water splitting for hydrogen production,yet its sluggish kinetics pose significant challenges for catalyst development.In this work,we present the first systematic study on isostructural 2D coordination polymers(CPs)based on 1,10-ferrocenediyl-bis(H-phosphinic)acid,with cobalt,manganese,and cadmium metals as electrocatalysts for OER.These polymers were synthesized via a facile solution reaction,yielding crystalline materials with excellent structural integrity.The electrocatalytic performance of CPs composites,prepared with carbon and phosphonium ionic liquid,was evaluated in 0.1 M KOH using a three-electrode system.Notably,the Co-and Cd-based CPs demonstrated exceptional OER activity,achieving an overpotential as low as 236–255 mV at 10 mA cm^(-2),surpassing those of many previously reported CP-based OER catalysts.Furthermore,these materials exhibited high stability over prolonged electrolysis,maintaining their activity without significant degradation.This work not only introduces a new class of ferrocenyl phosphinatebased CPs as highly active and durable OER catalysts but also provides valuable insights into their structureactivity relationships,paving the way for future advancements in electrocatalysis.展开更多
Rechargeable lithium-carbon dioxide(Li-CO_(2))batteries have emerged as a highly promising approach to simultaneously address energy shortages and the greenhouse effect.However,certain limitations exist in Li-CO_(2)ba...Rechargeable lithium-carbon dioxide(Li-CO_(2))batteries have emerged as a highly promising approach to simultaneously address energy shortages and the greenhouse effect.However,certain limitations exist in Li-CO_(2)batteries like high charge overpotential and unstable Li metal interface,which adversely affect the energy efficiency and cycling life.The incorporation of soluble redox mediators(RMs)has proven effective in enhancing the charge transfer between lithium carbonate(Li_(2)CO_(3))and cathode,thereby substantially reducing the charge overpotential.Nevertheless,the severe shuttle effect of RMs results in the reactions with Li anode,not only exacerbating the corrosion of Li anode but also leading to the depletion of RMs and electrical energy efficiency.In this work,an organic compound containing large cation group,1-ethyl-3-methylimidazole bromide(EMIBr)is proposed as the defense donor RM for Li anode in Li-CO_(2)batteries to address the above problems simultaneously.During charging,Li_(2)CO_(3)oxidation kinetics can be accelerated by bromide anion pair(Br_(3)^(−)/Br^(−)).Meanwhile,the cations(EMI^(+))are preferentially adsorbed around the protruding tips of Li anode through electrostatic interaction driven by surface free energy,forming protective layers that effectively inhibit further Li deposition at these tips,which is verified by DFT calculations.Additionally,Li dendrites growth is inhibited by the electrostatic repulsion of polar groups in EMIBr,resulting in uniform Li deposition.Consequently,a lower overpotential(∼1.17 V)and a longer cycle life(∼200 cycles)have been obtained for Li-CO_(2)battery incorporating EMIBr.展开更多
In the quest for high-efficiency and cost-effective catalysts for the oxygen evolution reaction(OER),a novel biomass-driven strategy is developed to fabricate a unique one-dimensional rod-arrays@two-dimensional interl...In the quest for high-efficiency and cost-effective catalysts for the oxygen evolution reaction(OER),a novel biomass-driven strategy is developed to fabricate a unique one-dimensional rod-arrays@two-dimensional interlaced-sheets(C_(1D@2D))network.A groundbreaking chemical fermentation(CF)pore-generation mechanism,proposed for the first time for creating nanopores within carbon structures,is based on the optimal balance between gasification and solidification.This mechanism not only results in a distinctive C_(1D@2D) multilevel network with nanoscale,intersecting and freely flowing channels but also introduces a novel concept for in situ,extensive and hierarchical pore formation.The unique architecture,combined with the homogeneous dispersion of Ni-Fe nanoparticles,facilitates easy electrolyte penetration and provides abundant active sites for the anchoring and dispersion of reactive molecules or ions.Consequently,the Ni-Fe@C_(1D@2D) porous network demonstrates an exceptional OER electrocatalytic performance,achieving a record-low overpotential of 165 mV at 10 mA cm^(−2)and maintaining long-term stability for over 90 h.Theoretical calculations reveal that the porous structure markedly strengthens the interaction between alloy nanoparticles and the carbon matrix,thereby significantly boosting their electrocatalytic activity and stability.These findings unequivocally validate the CF pore-generation mechanism as a powerful and innovative strategy for designing highly efficient functional nanostructures.展开更多
ZnO with good lithiophilicity has widely been employed to modify the lithiophobic substrates and facilitate uniform lithium(Li)deposition.The overpotential of ZnO-derived Li anode during cycling depends on the lithiop...ZnO with good lithiophilicity has widely been employed to modify the lithiophobic substrates and facilitate uniform lithium(Li)deposition.The overpotential of ZnO-derived Li anode during cycling depends on the lithiophilicity of both LiZn and Li_(2)O products upon lithiation of ZnO.However,the striking differences in the lithiophilicity between Li_(2)O and LiZn would result in a high overpotential during cycling.In this research,the Al_(2)O_(3)/nZnO(n≥1)hybrid layers were precisely fabricated by atomic layer deposition(ALD)to regulate the lithiophilicity of ZnO phase and Li_(2)O/LiZn configuration—determining the actual Li loading amount and Li plating/stripping processes.Theoretically,the Li adsorption energy(E_(a))values of LiZn and Li_(2)O in the LiZn/Li_(2)O configuration are separately predicted as-2.789 and-3.447 eV.In comparison,the E_(a) values of LiZn,LiAlO_(2),and Li_(2)O in the LiZn/LiAlO_(2)/Li_(2)O configuration upon lithiation of Al_(2)O_(3)/8ZnO layer are calculated as-2.899,-3.089,and-3.208 eV,respectively.Importantly,a novel introduction of LiAlO_(2)into the LiZn/Li_(2)O configuration could enable the hierarchical Li plating/stripping and reduce the overpotentials during cycling.Consequently,the Al_(2)O_(3)/8ZnO-derived hybrid Li-metal anode could exhibit electrochemical performances superior to these of ZnO-derived Li anode in both symmetrical and full cells paired with a LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622)cathode.展开更多
CO_(2)electroreduction to formate is technically feasible and economically viable,but still suffers from low selectivity and high overpotential at industrial current densities.Here,lattice-distorted metallic nanosheet...CO_(2)electroreduction to formate is technically feasible and economically viable,but still suffers from low selectivity and high overpotential at industrial current densities.Here,lattice-distorted metallic nanosheets with disorder-engineered metal sites are designed for industrial-current-density CO_(2)-to-formate conversion at low overpotentials.As a prototype,richly lattice-distorted bismuth nanosheets are first constructed,where abundant disorder-engineered Bi sites could be observed by high-angle annular dark-field scanning transmission electron microscopy image.In-situ Fourier-transform infrared spectra reveal the CO_(2)•−*group is the key intermediate,while theoretical calculations suggest the electron-enriched Bi sites could effectively lower the CO_(2)activation energy barrier by stabilizing the CO_(2)•−*intermediate,further affirmed by the decreased formation energy from 0.49 to 0.39 eV.As a result,the richly lattice-distorted Bi nanosheets exhibit the ultrahigh current density of 800 mA·cm^(−2)with 91%Faradaic efficiencies for CO_(2)-to-formate electroreduction,and the formate selectivity can reach nearly 100%at the current density of 200 mA·cm^(−2)with a very low overpotential of ca.570 mV,outperforming most reported metal-based electrocatalysts.展开更多
Developing new catalysts to decorate photoelectrodes has been widely used to enhance the performance of photoelectrochemical(PEC)cells.However,the high cost,complex synthesis,and poor stability of catalyst decoration ...Developing new catalysts to decorate photoelectrodes has been widely used to enhance the performance of photoelectrochemical(PEC)cells.However,the high cost,complex synthesis,and poor stability of catalyst decoration strongly hinder its practical application.Here,we report a facile and low-cost decoration of Ag-Pt nanoparticles(Ag-Pt NPs)on Si photocathodes with TiO_(2)/Ti sacrificial overlayers.Such a decoration does not rely on any metallic-ion precursor solution since it is formed automatically via galvanic replacement reactions during PEC measurements;that is,Ti is displaced by Ag^(+)and Pt^(2+)ions,which are from the employed reference and counter electrodes,respectively.The as-decorated Ag-Pt NPs are verified to significantly enhance the hydrogen evolution reduction kinetics without substantially degrading the optical performance of Si photocathodes.Owing to optoelectronic advantages,the overpotential required to maintain a photocurrent density of 10 mA cm(under AM1.5 G illumination)is reduced from-0.8 V_(RHE)(for the bare planar Si photocathode)to-0.1 V_(RHE)(for the planar Si photocathode with Ag-Pt NP decoration).Moreover,a further anodic shift(to 0 V_(RHE))is visible for the Si nanowire array photocathode with Ag-Pt NP decoration,along with high long-term stability of the PEC response in acidic and neutral electrolytes.This study opens a new opportunity for the photo-assisted decoration of various alloy NPs on the morphology-varying photoelectrodes with different applications.展开更多
Electrochemical CO_(2) reduction reaction(CO_(2)RR)into value-added chemicals/fuels is crucial for realizing the sustainable carbon cycle while mitigating the energy crisis.However,it is impeded by the relatively high...Electrochemical CO_(2) reduction reaction(CO_(2)RR)into value-added chemicals/fuels is crucial for realizing the sustainable carbon cycle while mitigating the energy crisis.However,it is impeded by the relatively high overpotential and low energy efficiency due to the lack of efficient electrocatalysts.Herein,we develop an isolated single-atom Ni catalyst regulated strategy to activate and stabilize the iron phthalocyanine molecule(Ni SA@FePc)toward a highly efficient CO_(2)RR process at low overpotential.The well-defined and homogenous catalytic centers with unique structures confer Ni SA@FePc with a significantly enhanced CO_(2)RR performance compared to single-atom Ni catalyst and FePc molecule and afford the atomic understanding on active sites and catalytic mechanism.As expected,Ni SA@FePc exhibits a high selectivity of more significant Faraday efficiency(≥95%)over a wide potential range,a high current density of~252 mA·cm^(−2) at low overpotential(390 mV),and excellent long-term stability for CO_(2)RR to CO.X-ray absorption spectroscopy measurement and theoretical calculation indicate the formation of NiN_(4)-O_(2)-FePc heterogeneous structure for Ni SA@FePc.And CO_(2)RR prefers to occur at the raised N centers of NiN4-O_(2)-FePc heterogeneous structure for Ni SA@FePc,which enables facilitated adsorption of*COOH and desorption of CO,and thus accelerated overall reaction kinetics.展开更多
The pH gradient caused by H^(+)/OH^(−)transport on an electrode surface is the key factor determining reaction performance,but its detailed impact on the electrode reaction kinetics has yet to be clarified.Here,the pH...The pH gradient caused by H^(+)/OH^(−)transport on an electrode surface is the key factor determining reaction performance,but its detailed impact on the electrode reaction kinetics has yet to be clarified.Here,the pH gradient effect was determined by developing electrode reaction equations,considering the overpotential assigned to the pH gradient called pH overpotential.The pH gradient effect was revealed to involve two aspects:(1)the Nernst pH overpotential,accounting for the common Nernst relationship with pH,and(2)the pH-dependent function of the electron-transfer coefficient(α_(pH)).Both parts were verified experimentally using oxygen reduction reaction and hydrogen evolution reaction,obviously,with differentα_(pH) functions.Detailedα_(pH) function effect was clarified based on numerical calculations of the electrode reaction equations.We found that the effect could be assessed suitably by an apparent constant(α_(app))and a nonlinear fitting method proposed forα_(app) value estimation.The results of this study provide the kinetic fundamentals of electrode reactions involving H^(+)/OH^(−)and contribute to the understanding and assessment of their performance with the H^(+)/OH^(−)transport effect.展开更多
Biomass electrooxidation has garnered much attention in recent years,owing to its potential to circumvent greenhouse gas emissions.Substituting the sluggish water oxidation with biomass oxidizable species such as lign...Biomass electrooxidation has garnered much attention in recent years,owing to its potential to circumvent greenhouse gas emissions.Substituting the sluggish water oxidation with biomass oxidizable species such as lignin at anode is thermodynamically more favorable,enabling energy efficient hydrogen production and concomitant fine chemicals.The present study shows the organosolv lignin electrooxidation in an additively manufactured 3D printed reactor(3DPR)consisting of platinized nickel foam(PtNF)as anode and cathode and compared with commercial hardware electrolyzer(CHE).The electrolysis of organosolv lignin in 3DPR outperformed CHE by achieving 1.23 times higher current at an applied voltage range from 0 to 2.2 V with a membrane(Nafion 115)interposed between anode and cathode under a continuous flow of lignin feed at the anode.The chronoamperometry study reveals a mixture of diverse aromatic compounds,including vanillic acid,syringic acid,3,5-dimethoxy-4-hydroxyacetophenone,2-hydroxyacetophenone,4-ethycathecol,and 2,6-dimethoxyphenol in anolyte,and sinapic acid and vanillin acetate in catholyte.Thus,realizing renewable biomass electrolysis in the 3DPR is an intriguing strategy for the co-production of hydrogen and fine aromatic chemicals.展开更多
Subnanometer metal clusters play an increasingly important role in heterogeneous catalysis due to their high catalytic activity and selectivity.In this work,by means of the density functional theory(DFT) calculations,...Subnanometer metal clusters play an increasingly important role in heterogeneous catalysis due to their high catalytic activity and selectivity.In this work,by means of the density functional theory(DFT) calculations,the catalytic activities of transition metal clusters with precise numbers of atoms supported on graphdiyne(TM_(1-4)@GDY,TM=V,Cr,Mn,Fe,Co,Ni,Cu,Ru,Rh,Pd,Ir,Pt) were investigated for oxygen evolution reactions(OER),oxygen reduction reactions(ORR) and hydrogen evolution reactions(HER).The computed results reveal that the Pd_(2),Pd_(4) and Pt_(1) anchored graphdiyne can serve as trifunctional catalysts for OER/ORR/HER with the overpotentials of 0.49/0.37/0.06,0.45/0.33/0.12 and 0.37/0.43/0.01 V,respectively,while Pd_(1) and Pt_(2)@graphdiyne can exhibit excellent catalytic performance for water splitting(OER/HER) with the overpotentials of 0.55/0.17 and 0.43/0.03 V.In addition,Ni_(1) and Pd_(3) anchored GDY can perform as bifunctional catalysts for metal-air cells(OER/ORR) and fuels cells(ORR/HER) with the overpotentials of 0.34/0.32 and 0.42/0.04 V,respectively.Thus,by precisely controlling the numbers of atoms in clusters,the TM_(1-4) anchored graphdiyne can serve as promising multifunctional electrocatalysts for OER/ORR/HER,which may provide an instructive strategy to design catalysts for the energy conversation and storage devices.展开更多
Nano-CeO2 （RE） particles were co-deposited into Ni-P binary composite coatings by applying pulse current （PC） under ultrasonic （U） field. Morphology, chemical content and crystal microstructure were characterize...Nano-CeO2 （RE） particles were co-deposited into Ni-P binary composite coatings by applying pulse current （PC） under ultrasonic （U） field. Morphology, chemical content and crystal microstructure were characterized by environmental scanning electron microscopy （E-SEM） with energy dispersive X-ray analysis （EDXA）, XRD diffractometry and transmission electron microscopy （TEM）. Experimental results show that Ni-P coating reinforced with 15g/L nano-CeO2, in amorphous state and with compact structure, can be improved in the microhardness from HV0.2580 to HV0.2780 by annealing at 600 °C for 2 h. The highest content of codeposited Ce and deposition rate can reach 2.3% and 68 μm/h, respectively. Furthermore, the effect of RE adsorption and pulse overpotential on depositional mechanism was investigated. n-CeO2 particles or Ce4＋ ions with strong adsorption capacity acted as the catalytic nucleus to improve densification effectively. During annealing at 600 °C for 2 h, n-CeO2 particles will uniformly adsorb on crystal grain to preferentially pad and heal up gaps of cracking Ni boundaries, promoting dispersion strengthening with refiner-grained structure.展开更多
基金supported by the National Key R&D Program of China 2022YFB2404300the National Natural Science Foundation of China U22B2069the China Postdoctoral Science Foundation 2024M761006。
文摘The reaction rate constant is a crucial kinetic parameter that governs the charge and discharge performance of batteries,particularly in high-rate and thick-electrode applications.However,conventional estimation or fitting methods often overestimate the charge transfer overpotential,leading to substantial errors in reaction rate constant measurements.These inaccuracies hinder the accurate prediction of voltage profiles and overall cell performance.In this study,we propose the characteristic time-decomposed overpotential(CTDO)method,which employs a single-layer particle electrode(SLPE)structure to eliminate interference overpotentials.By leveraging the distribution of relaxation times(DRT),our method effectively isolates the characteristic time of the charge transfer process,enabling a more precise determination of the reaction rate constant.Simulation results indicate that our approach reduces measurement errors to below 2%,closely aligning with theoretical values.Furthermore,experimental validation demonstrates an 80% reduction in error compared to the conventional galvanostatic intermittent titration technique(GITT)method.Overall,this study provides a novel voltage-based approach for determining the reaction rate constant,enhancing the applicability of theoretical analysis in electrode structural design and facilitating rapid battery optimization.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.52171206 and52271209)Key Project of Hebei Natural Science Foundation(Nos.F2024201031 and E20202201030)+4 种基金Beijing-Tianjin-Hebei Collaborative Innovation Community Construction Project(No.21344301D)the Second Batch of Young Talent of Hebei Province(Nos.70280016160250 and 70280011808)Key Fund in Hebei Province Department of Education China(No.ZD2021014)the Central Government Guide Local Funding Projects for Scientific and Technological Development(Nos.216Z4404G and 206Z4402G)Interdisciplinary Research Program of Natural Science of Hebei University(No.DXK202107)。
文摘The lithium-oxygen battery(LOB)is a promising source of green energy due to its energy density.However,the development of this technology is limited by the insoluble discharge product it produces.In this work,a cathode material with a p-n heterostructure of polyaniline(PANI)/ZnS is prepared to trap visible light,utilizing a ZnS quantum dot(ZnS QD)network to form a large number of photogenerated electron–hole pairs,thus promoting the generation and decomposition of Li_(2)O_(2).The prepared PANI/ZnS has an ultra-low overpotential of 0.06 V under illumination.Furthermore,density functional theory theoretical calculation has demonstrated the ability of the heterostructures to adsorb oxygen-containing intermediates,which not only facilitates the growth of Li_(2)O_(2),but also reduces the reaction energy required to decompose Li_(2)O_(2).The present work provides a solution to the problem of insolubility of discharge products in photo-assisted LOB.
文摘It is well known that transition metal sulfides(TMS)(i.e.,NiS_(2))undergo electrochemical reconstructions to generate highly active Ni_(3)S_(2) during the process of hydrogen evolution reaction(HER)under overpotentials of<500 mV.However,at higher overpotentials,Ni_(3)S_(2) can theoretically be further restructured into Ni and thus form Ni/Ni_(3)S_(2) heterogeneous interface structures,which may provide opportunities to further enhance HER activity of NiS_(2).Here,we selected NiS_(2) as a model electrocatalyst and investigated the influence of the reconstruction results induced from regular to ultrahigh overpotentials on its electrocatalytic hydrogen precipitation performance.The experimental results showed that the most significant enhancement of hydrogen precipitation performance was obtained for the NiS_(2)@CC-900(900 means 900 mV overpotential)sample after the ultra-high overpotential induced reconstruction.Compared with the initial overpotential of 161 mV(10 mA cm^(-2)),the overpotential of the reconstructed sample reduced by 67 mV(42%).The characterization results showed that an ultra-high overpotential of 900 mV induced deep reconstruction of NiS_(2),formed highly reactive Ni/Ni_(3)S_(2) heterogeneous interfaces,which is more conducive to improved HER performance and match well with theoretical calculations results.We demonstrated ultrahigh overpotential was an effective strategy to induce NiS_(2) deeply reconstruction and significantly improve its HER performance,and this strategy was also applicable to CoS_(2) and FeS_(2).This study provides an extremely simple and universal pathway for the reasonable construction of efficient electrocatalysts by induced TMS deeply reconstruction.
基金supported by the National Key R&D Program of China (2022YFB3305400)Beijing Natural Science Foundation (Z220021)+3 种基金Science and Technology Innovation Program Talent Cultivation Project of Beijing Institute of Technology (2021CX01012)the National Natural Science Foundation of China (51972030, 22202011)Beijing Outstanding Young Scientists Program (BJJWZYJH01201910007023)Natural Science Foundation of Shandong Province (ZR2022QB056)。
文摘Dendrite formation severely compromises further development of zinc ion batteries. Increasing the nucleation overpotential plays a crucial role in achieving uniform deposition of metal ions. However, this strategy has not yet attracted enough attention from researchers to our knowledge. Here, we propose that thermodynamic nucleation overpotential of Zn deposition can be boosted through complexing agent and select sodium L-tartrate(Na-L) as example. Theoretical and experimental characterization reveals L-tartrate anion can partially replace H_(2)O in the solvation sheath of Zn^(2+), increasing de-solvation energy. Concurrently, the Na^(+) could absorb on the surface of Zn anode preferentially to inhibit the deposition of Zn^(2+) aggregation. In consequence, the overpotential of Zn deposition could increase from 32.2 to 45.1 mV with the help of Na-L. The Zn-Zn cell could achieve a Zn utilization rate of 80% at areal capacity of 20 mAh cm^(-2). Zn-LiMn_(2)O_(4) full cell with Na-L additive delivers improved stability than that with blank electrolyte. This study also provides insight into the regulation of nucleation overpotential to achieve homogeneous Zn deposition.
基金the financial support from the National Natural Science Foundation of China(91645102)the Singapore MOE grant(R143-000-A29-112)the Hundred Talents Sailing Project of Jiangxi province,China。
文摘Achieving low charge overpotentials represents one of the most critical challenges for pursuing highperformance lithium-oxygen(Li-O_(2))batteries.Herein,we propose a strategy to realize low charge overpotentials by confining the growth of lithium peroxide(Li_(2)O_(2))inside mesoporous channels of cathodes(CMK-8).The CMK-8 cathode with tortuous pore structures can extend the diffusion distance of lithium superoxide(LiO_(2))in the mesoporous channels,facilitating the further reduction of LiO_(2) to lithium peroxide(Li_(2)O_(2))inside the pores and preventing them to be diffused out of the pores.Therefore,Li_(2)O_(2) is trapped in the mesoporous channels of CMK-8 cathodes,ensuring a good Li_(2)O_(2)/CMK-8 contact interface.The CMK-8 electrode exhibits a low charge overpotential of 0.43 V and a good cycle life for 72 cycles with a fixed capacity of 500 m Ah g^(-1) at 0.1 A g^(-1).This study proposes a strategy to achieve a low charge overpotential by confining Li_(2)O_(2) growth in the mesoporous channels of cathodes.
基金supported by the National Natural Science Foundations of China(21965024,22269016,51721002)the Inner Mongolia funding(2020JQ01,21300-5223601)the funding of Inner Mongolia University(10000-21311201/137,213005223601/003,21300-5223707)。
文摘Generating sufficient strains on metal surfaces are highly challenging owing to that most metals can deform plastically to relax the strains on the surfaces.In this work,we developed a facile but highly efficient stacked deposition strategy to in situ activation and reconstruction of NiO/NiOOH on Ni matrix,following with the migration of Fe ions to NiOOH.The Fe sites on the Ni/NiO/NiOOH facilitate the formation of the stable*OH oxygenated intermediates,and the Ni matrix in the catalyst provides the catalyst excellent stability.The oxygen evolution reaction(OER)performance of the stacked NiFe-5 with compressive strain displays the strengthened binding to oxygenated intermediates and superior OER activity,the ultralow overpotentials of 162 versus reversible hydrogen electrode at 10 mA cm^(-2).On the other hand,the Ni-5 without the incorporation of Fe has shown an outstanding hydrogen evolution reaction(HER)activity,affording an overpotential of 47 mV at 10 mA cm^(-2).The NiFe-5‖Ni-5 enables the overall water splitting at a voltage of 1.508 V to achieve 20 mA cm^(-2) with remarkable durability.The stacked deposition strategy improves binding strength of Ni-based catalysts to oxygenated intermediates via generating compressive strain,causing high catalytic activities on OER and HER.
基金supported by the National Natural Science Foundation of China(Grant Nos.12192214,12272338,12102387)the Key Research Project of Zhejiang Laboratory(Grant No.2021PE0AC02)+1 种基金the support provided by RGC Postdoctoral Fellowship Scheme(Grant No.PDFS2223-5S08)the PolyU Distinguished Postdoctoral Fellowship Scheme(Grant No.1-YWBC)。
文摘Dendrite growth is one of the main challenges in maintaining the service life of all-solid-state lithium-ion batteries.Mechanical stress has been reported to significantly affect dendrite growth.In this study,to explain the effect of mechanical stress on electrochemical reactions in all-solid-state batteries,a modified phase-field model for dendrite growth is proposed by considering the stress-dependent overpotential.Dendrite growth under different mechanical loadings in an all-solid-state battery is investigated using the proposed model.Consistent with previous experimental results,the current result shows that compressive stress inhibits dendrite growth.Considering the stress concentration at the tips of processing-induced microcracks,the effects of the number and distribution of microcracks on dendrite growth are investigated.The results show that the stress-concentration field induced at the tips of cracks or voids can change the morphology of dendrites and decrease their growth rates.This study provides a new perspective for explaining Li dendrite growth under mechanical stress and offers inspiration for prolonging the service life of all-solid-state batteries based on defect and stress regulation,which may be further realized in experiments by filling solid electrolytes with different types of nanofillers.
基金supported by the National Natural Science Foundation of China(Nos.22125903 and 51872283)Dalian Innovation Support Plan for High Level Talents(No.2019RT09)+2 种基金Dalian National Laboratory for Clean Energy(DNL),CAS,DNL Cooperation Fund,CAS(Nos.DNL201912,DNL201915,DNL202016,and DNL202019)DICP(No.DICP I2020032)the Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy(Nos.YLU‐DNL Fund 2021002 and YLU‐DNL 2021009).
文摘The realization of high‐efficiency,reversible,stable,and safe Li‐O2 batteries is severely hindered by the large overpotential and side reactions,especially at high rate conditions.Therefore,rational design of cathode catalysts with high activity and stability is crucial to overcome the terrible issues at high current density.Herein,we report a surface engineering strategy to adjust the surface electron structure of boron(B)‐doped PtNi nanoalloy on carbon nanotubes(PtNiB@CNTs)as an efficient bifunctional cathodic catalyst for high‐rate and long‐life Li‐O2 batteries.Notably,the Li‐O2 batteries assembled with as‐prepared PtNiB@CNT catalyst exhibit ultrahigh discharge capacity of 20510 mA·h/g and extremely low overpotential of 0.48 V at a high current density of 1000 mA/g,both of which outperform the most reported Pt‐based catalysts recently.Meanwhile,our Li‐O2 batteries offer excellent rate capability and ultra‐long cycling life of up to 210 cycles at 1000 mA/g under a fixed capacity of 1000 mA·h/g,which is two times longer than those of Pt@CNTs and PtNi@CNTs.Furthermore,it is revealed that surface engineering of PtNi nanoalloy via B doping can efficiently tailor the electron structure of nanoalloy and optimize the adsorption of oxygen species,consequently delivering excellent Li‐O2 battery performance.Therefore,this strategy of regulating the nanoalloy by doping nonmetallic elements will pave an avenue for the design of high‐performance catalysts for metal‐oxygen batteries.
文摘The oxygen evolution reaction(OER)is a key process in water splitting for hydrogen production,yet its sluggish kinetics pose significant challenges for catalyst development.In this work,we present the first systematic study on isostructural 2D coordination polymers(CPs)based on 1,10-ferrocenediyl-bis(H-phosphinic)acid,with cobalt,manganese,and cadmium metals as electrocatalysts for OER.These polymers were synthesized via a facile solution reaction,yielding crystalline materials with excellent structural integrity.The electrocatalytic performance of CPs composites,prepared with carbon and phosphonium ionic liquid,was evaluated in 0.1 M KOH using a three-electrode system.Notably,the Co-and Cd-based CPs demonstrated exceptional OER activity,achieving an overpotential as low as 236–255 mV at 10 mA cm^(-2),surpassing those of many previously reported CP-based OER catalysts.Furthermore,these materials exhibited high stability over prolonged electrolysis,maintaining their activity without significant degradation.This work not only introduces a new class of ferrocenyl phosphinatebased CPs as highly active and durable OER catalysts but also provides valuable insights into their structureactivity relationships,paving the way for future advancements in electrocatalysis.
基金financially supported by National Natural Science Foundation of China(No.22075171).
文摘Rechargeable lithium-carbon dioxide(Li-CO_(2))batteries have emerged as a highly promising approach to simultaneously address energy shortages and the greenhouse effect.However,certain limitations exist in Li-CO_(2)batteries like high charge overpotential and unstable Li metal interface,which adversely affect the energy efficiency and cycling life.The incorporation of soluble redox mediators(RMs)has proven effective in enhancing the charge transfer between lithium carbonate(Li_(2)CO_(3))and cathode,thereby substantially reducing the charge overpotential.Nevertheless,the severe shuttle effect of RMs results in the reactions with Li anode,not only exacerbating the corrosion of Li anode but also leading to the depletion of RMs and electrical energy efficiency.In this work,an organic compound containing large cation group,1-ethyl-3-methylimidazole bromide(EMIBr)is proposed as the defense donor RM for Li anode in Li-CO_(2)batteries to address the above problems simultaneously.During charging,Li_(2)CO_(3)oxidation kinetics can be accelerated by bromide anion pair(Br_(3)^(−)/Br^(−)).Meanwhile,the cations(EMI^(+))are preferentially adsorbed around the protruding tips of Li anode through electrostatic interaction driven by surface free energy,forming protective layers that effectively inhibit further Li deposition at these tips,which is verified by DFT calculations.Additionally,Li dendrites growth is inhibited by the electrostatic repulsion of polar groups in EMIBr,resulting in uniform Li deposition.Consequently,a lower overpotential(∼1.17 V)and a longer cycle life(∼200 cycles)have been obtained for Li-CO_(2)battery incorporating EMIBr.
基金supported by the National Natural Science Foundation of China(Grant No.22275082 and 22175084).
文摘In the quest for high-efficiency and cost-effective catalysts for the oxygen evolution reaction(OER),a novel biomass-driven strategy is developed to fabricate a unique one-dimensional rod-arrays@two-dimensional interlaced-sheets(C_(1D@2D))network.A groundbreaking chemical fermentation(CF)pore-generation mechanism,proposed for the first time for creating nanopores within carbon structures,is based on the optimal balance between gasification and solidification.This mechanism not only results in a distinctive C_(1D@2D) multilevel network with nanoscale,intersecting and freely flowing channels but also introduces a novel concept for in situ,extensive and hierarchical pore formation.The unique architecture,combined with the homogeneous dispersion of Ni-Fe nanoparticles,facilitates easy electrolyte penetration and provides abundant active sites for the anchoring and dispersion of reactive molecules or ions.Consequently,the Ni-Fe@C_(1D@2D) porous network demonstrates an exceptional OER electrocatalytic performance,achieving a record-low overpotential of 165 mV at 10 mA cm^(−2)and maintaining long-term stability for over 90 h.Theoretical calculations reveal that the porous structure markedly strengthens the interaction between alloy nanoparticles and the carbon matrix,thereby significantly boosting their electrocatalytic activity and stability.These findings unequivocally validate the CF pore-generation mechanism as a powerful and innovative strategy for designing highly efficient functional nanostructures.
基金supported by the National Key Research and Development Program of China(2021YFB2400202)the National Natural Science Foundation of China(52104313)+1 种基金the Key Research and Development Plan of Shaanxi(2024GH-YBXM-11)the Foshan Science and Technology Innovation Team Project(1920001004098).
文摘ZnO with good lithiophilicity has widely been employed to modify the lithiophobic substrates and facilitate uniform lithium(Li)deposition.The overpotential of ZnO-derived Li anode during cycling depends on the lithiophilicity of both LiZn and Li_(2)O products upon lithiation of ZnO.However,the striking differences in the lithiophilicity between Li_(2)O and LiZn would result in a high overpotential during cycling.In this research,the Al_(2)O_(3)/nZnO(n≥1)hybrid layers were precisely fabricated by atomic layer deposition(ALD)to regulate the lithiophilicity of ZnO phase and Li_(2)O/LiZn configuration—determining the actual Li loading amount and Li plating/stripping processes.Theoretically,the Li adsorption energy(E_(a))values of LiZn and Li_(2)O in the LiZn/Li_(2)O configuration are separately predicted as-2.789 and-3.447 eV.In comparison,the E_(a) values of LiZn,LiAlO_(2),and Li_(2)O in the LiZn/LiAlO_(2)/Li_(2)O configuration upon lithiation of Al_(2)O_(3)/8ZnO layer are calculated as-2.899,-3.089,and-3.208 eV,respectively.Importantly,a novel introduction of LiAlO_(2)into the LiZn/Li_(2)O configuration could enable the hierarchical Li plating/stripping and reduce the overpotentials during cycling.Consequently,the Al_(2)O_(3)/8ZnO-derived hybrid Li-metal anode could exhibit electrochemical performances superior to these of ZnO-derived Li anode in both symmetrical and full cells paired with a LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622)cathode.
基金the National Key Research and Development Program of China(No.2019YFA0210004)the National Natural Science Foundation of China(Nos.22125503,21975242,U2032212,and 21890754)+5 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB36000000)Youth Innovation Promotion Association of CAS(No.CX2340007003)the Key Research Program of Frontier Sciences of CAS(No.QYZDY-SSW-SLH011)the Major Program of Development Foundation of Hefei Center for Physical Science and Technology(No.2020HSC-CIP003)Users with Excellence Program of Hefei Science Center CAS(No.2020HSC-UE001)the University Synergy Innovation Program of Anhui Province(No.GXXT-2020-001)。
文摘CO_(2)electroreduction to formate is technically feasible and economically viable,but still suffers from low selectivity and high overpotential at industrial current densities.Here,lattice-distorted metallic nanosheets with disorder-engineered metal sites are designed for industrial-current-density CO_(2)-to-formate conversion at low overpotentials.As a prototype,richly lattice-distorted bismuth nanosheets are first constructed,where abundant disorder-engineered Bi sites could be observed by high-angle annular dark-field scanning transmission electron microscopy image.In-situ Fourier-transform infrared spectra reveal the CO_(2)•−*group is the key intermediate,while theoretical calculations suggest the electron-enriched Bi sites could effectively lower the CO_(2)activation energy barrier by stabilizing the CO_(2)•−*intermediate,further affirmed by the decreased formation energy from 0.49 to 0.39 eV.As a result,the richly lattice-distorted Bi nanosheets exhibit the ultrahigh current density of 800 mA·cm^(−2)with 91%Faradaic efficiencies for CO_(2)-to-formate electroreduction,and the formate selectivity can reach nearly 100%at the current density of 200 mA·cm^(−2)with a very low overpotential of ca.570 mV,outperforming most reported metal-based electrocatalysts.
基金supported by the National Natural Science Foundation of China(62075146 and 61875143)the Natural Science Foundation of Jiangsu Province(BK20181169)+3 种基金the Natural Science Foundation of Jiangsu Higher Education Institutions(20KJA510003)Qinglan Project of Jiangsu Provincethe Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutionsthe Natural Science Research of Jiangsu Higher Education Institutions。
文摘Developing new catalysts to decorate photoelectrodes has been widely used to enhance the performance of photoelectrochemical(PEC)cells.However,the high cost,complex synthesis,and poor stability of catalyst decoration strongly hinder its practical application.Here,we report a facile and low-cost decoration of Ag-Pt nanoparticles(Ag-Pt NPs)on Si photocathodes with TiO_(2)/Ti sacrificial overlayers.Such a decoration does not rely on any metallic-ion precursor solution since it is formed automatically via galvanic replacement reactions during PEC measurements;that is,Ti is displaced by Ag^(+)and Pt^(2+)ions,which are from the employed reference and counter electrodes,respectively.The as-decorated Ag-Pt NPs are verified to significantly enhance the hydrogen evolution reduction kinetics without substantially degrading the optical performance of Si photocathodes.Owing to optoelectronic advantages,the overpotential required to maintain a photocurrent density of 10 mA cm(under AM1.5 G illumination)is reduced from-0.8 V_(RHE)(for the bare planar Si photocathode)to-0.1 V_(RHE)(for the planar Si photocathode with Ag-Pt NP decoration).Moreover,a further anodic shift(to 0 V_(RHE))is visible for the Si nanowire array photocathode with Ag-Pt NP decoration,along with high long-term stability of the PEC response in acidic and neutral electrolytes.This study opens a new opportunity for the photo-assisted decoration of various alloy NPs on the morphology-varying photoelectrodes with different applications.
基金supported by the National Natural Science Foundation of China(No.21725103)National Key R&D Program of China(No.2019YFA0705704)+4 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA21010210)Jilin Province Science and Technology Development Plan Funding Project(No.20200201079JC)Changchun Science and Technology Development Plan Funding Project(No.19SS010)Jilin Province Capital Construction Funds Project(No.2020C026-1)the K.C.Wong Education Foundation(No.GJTD-2018-09).
文摘Electrochemical CO_(2) reduction reaction(CO_(2)RR)into value-added chemicals/fuels is crucial for realizing the sustainable carbon cycle while mitigating the energy crisis.However,it is impeded by the relatively high overpotential and low energy efficiency due to the lack of efficient electrocatalysts.Herein,we develop an isolated single-atom Ni catalyst regulated strategy to activate and stabilize the iron phthalocyanine molecule(Ni SA@FePc)toward a highly efficient CO_(2)RR process at low overpotential.The well-defined and homogenous catalytic centers with unique structures confer Ni SA@FePc with a significantly enhanced CO_(2)RR performance compared to single-atom Ni catalyst and FePc molecule and afford the atomic understanding on active sites and catalytic mechanism.As expected,Ni SA@FePc exhibits a high selectivity of more significant Faraday efficiency(≥95%)over a wide potential range,a high current density of~252 mA·cm^(−2) at low overpotential(390 mV),and excellent long-term stability for CO_(2)RR to CO.X-ray absorption spectroscopy measurement and theoretical calculation indicate the formation of NiN_(4)-O_(2)-FePc heterogeneous structure for Ni SA@FePc.And CO_(2)RR prefers to occur at the raised N centers of NiN4-O_(2)-FePc heterogeneous structure for Ni SA@FePc,which enables facilitated adsorption of*COOH and desorption of CO,and thus accelerated overall reaction kinetics.
基金supported by the National Natural Science Foundation of China(grant nos.51525805,51727812,and 51808526).
文摘The pH gradient caused by H^(+)/OH^(−)transport on an electrode surface is the key factor determining reaction performance,but its detailed impact on the electrode reaction kinetics has yet to be clarified.Here,the pH gradient effect was determined by developing electrode reaction equations,considering the overpotential assigned to the pH gradient called pH overpotential.The pH gradient effect was revealed to involve two aspects:(1)the Nernst pH overpotential,accounting for the common Nernst relationship with pH,and(2)the pH-dependent function of the electron-transfer coefficient(α_(pH)).Both parts were verified experimentally using oxygen reduction reaction and hydrogen evolution reaction,obviously,with differentα_(pH) functions.Detailedα_(pH) function effect was clarified based on numerical calculations of the electrode reaction equations.We found that the effect could be assessed suitably by an apparent constant(α_(app))and a nonlinear fitting method proposed forα_(app) value estimation.The results of this study provide the kinetic fundamentals of electrode reactions involving H^(+)/OH^(−)and contribute to the understanding and assessment of their performance with the H^(+)/OH^(−)transport effect.
基金This project received financial support from Natural Sciences and Engineering Research Council of Canada via a Discovery Grant(2022-00058)Canada Research Chair Fund(3266004)+1 种基金The Fonds de recherche du Quebec-Nature et technologies FRQNT(NCR-327419)We would also like to thank Intlvac Thin Film team for the support.
文摘Biomass electrooxidation has garnered much attention in recent years,owing to its potential to circumvent greenhouse gas emissions.Substituting the sluggish water oxidation with biomass oxidizable species such as lignin at anode is thermodynamically more favorable,enabling energy efficient hydrogen production and concomitant fine chemicals.The present study shows the organosolv lignin electrooxidation in an additively manufactured 3D printed reactor(3DPR)consisting of platinized nickel foam(PtNF)as anode and cathode and compared with commercial hardware electrolyzer(CHE).The electrolysis of organosolv lignin in 3DPR outperformed CHE by achieving 1.23 times higher current at an applied voltage range from 0 to 2.2 V with a membrane(Nafion 115)interposed between anode and cathode under a continuous flow of lignin feed at the anode.The chronoamperometry study reveals a mixture of diverse aromatic compounds,including vanillic acid,syringic acid,3,5-dimethoxy-4-hydroxyacetophenone,2-hydroxyacetophenone,4-ethycathecol,and 2,6-dimethoxyphenol in anolyte,and sinapic acid and vanillin acetate in catholyte.Thus,realizing renewable biomass electrolysis in the 3DPR is an intriguing strategy for the co-production of hydrogen and fine aromatic chemicals.
基金financially supported by Fundamental Research Funds for Heilongjiang Province universities (No.2021-KYYWF-0184)Harbin Normal University Graduate Student Innovation Project (No.HSDSSCX2023-30)。
文摘Subnanometer metal clusters play an increasingly important role in heterogeneous catalysis due to their high catalytic activity and selectivity.In this work,by means of the density functional theory(DFT) calculations,the catalytic activities of transition metal clusters with precise numbers of atoms supported on graphdiyne(TM_(1-4)@GDY,TM=V,Cr,Mn,Fe,Co,Ni,Cu,Ru,Rh,Pd,Ir,Pt) were investigated for oxygen evolution reactions(OER),oxygen reduction reactions(ORR) and hydrogen evolution reactions(HER).The computed results reveal that the Pd_(2),Pd_(4) and Pt_(1) anchored graphdiyne can serve as trifunctional catalysts for OER/ORR/HER with the overpotentials of 0.49/0.37/0.06,0.45/0.33/0.12 and 0.37/0.43/0.01 V,respectively,while Pd_(1) and Pt_(2)@graphdiyne can exhibit excellent catalytic performance for water splitting(OER/HER) with the overpotentials of 0.55/0.17 and 0.43/0.03 V.In addition,Ni_(1) and Pd_(3) anchored GDY can perform as bifunctional catalysts for metal-air cells(OER/ORR) and fuels cells(ORR/HER) with the overpotentials of 0.34/0.32 and 0.42/0.04 V,respectively.Thus,by precisely controlling the numbers of atoms in clusters,the TM_(1-4) anchored graphdiyne can serve as promising multifunctional electrocatalysts for OER/ORR/HER,which may provide an instructive strategy to design catalysts for the energy conversation and storage devices.
基金Project (CXLX12_0151) supported by Jiangsu Innovation program for Graduate Education and Fundamental Research Funds for Central Unibersities, China
文摘Nano-CeO2 （RE） particles were co-deposited into Ni-P binary composite coatings by applying pulse current （PC） under ultrasonic （U） field. Morphology, chemical content and crystal microstructure were characterized by environmental scanning electron microscopy （E-SEM） with energy dispersive X-ray analysis （EDXA）, XRD diffractometry and transmission electron microscopy （TEM）. Experimental results show that Ni-P coating reinforced with 15g/L nano-CeO2, in amorphous state and with compact structure, can be improved in the microhardness from HV0.2580 to HV0.2780 by annealing at 600 °C for 2 h. The highest content of codeposited Ce and deposition rate can reach 2.3% and 68 μm/h, respectively. Furthermore, the effect of RE adsorption and pulse overpotential on depositional mechanism was investigated. n-CeO2 particles or Ce4＋ ions with strong adsorption capacity acted as the catalytic nucleus to improve densification effectively. During annealing at 600 °C for 2 h, n-CeO2 particles will uniformly adsorb on crystal grain to preferentially pad and heal up gaps of cracking Ni boundaries, promoting dispersion strengthening with refiner-grained structure.
