The poor electrical conductivity of metal-organic frameworks(MOFs)limits their electrocatalytic performance in the oxygen evolution reaction(OER).In this study,a Py@Co-MOF composite material based on pyrene(Py)molecul...The poor electrical conductivity of metal-organic frameworks(MOFs)limits their electrocatalytic performance in the oxygen evolution reaction(OER).In this study,a Py@Co-MOF composite material based on pyrene(Py)molecules and{[Co2(BINDI)(DMA)_(2)]·DMA}_(n)(Co-MOF,H4BINDI=N,N'-bis(5-isophthalic acid)naphthalenediimide,DMA=N,N-dimethylacetamide)was synthesized via a one-pot method,leveragingπ-πinteractions between pyrene and Co-MOF to modulate electrical conductivity.Results demonstrate that the Py@Co-MOF catalyst exhibited significantly enhanced OER performance compared to pure Co-MOF or pyrene-based electrodes,achieving an overpotential of 246 mV at a current density of 10 mA·cm^(-2) along with excellent stability.Density functional theory(DFT)calculations reveal that the formation of O*in the second step is the rate-determining step(RDS)during the OER process on Co-MOF,with an energy barrier of 0.85 eV due to the weak adsorption affinity of the OH*intermediate for Co sites.CCDC:2419276.展开更多
A composite electrocatalyst,CoMoNiO-S/NF-110(NF is nickel foam),was synthesized through electrodeposition,followed by pyrolysis and then the vulcanization process.CoMoNiO-S/NF-110 exhibited a structure where Ni3S2 and...A composite electrocatalyst,CoMoNiO-S/NF-110(NF is nickel foam),was synthesized through electrodeposition,followed by pyrolysis and then the vulcanization process.CoMoNiO-S/NF-110 exhibited a structure where Ni3S2 and Mo2S3 nanoparticles were integrated at the edges of Co3O4 nanosheets,creating a rich,heterogeneous interface that enhances the synergistic effects of each component.In an alkaline electrolyte,the synthesized CoMoNiO-S/NF-110 exhibited superior electrocatalytic performance for oxygen evolution reaction(OER),achieving current densities of 100 and 200 mA·cm^(-2) with low overpotentials of 199.4 and 224.4 mV,respectively,outperforming RuO2 and several high-performance Mo and Ni-based catalysts.This excellent performance is attributed to the rich interface formed between the components and active sites exposed by the defect structure.展开更多
Hydrogen production from water electrolysis,in particular from proton exchange membrane water electrolyzers(PEMWE),is a key approach to realizing a carbon-free energy cycle.However,the high anodic potential and strong...Hydrogen production from water electrolysis,in particular from proton exchange membrane water electrolyzers(PEMWE),is a key approach to realizing a carbon-free energy cycle.However,the high anodic potential and strong acid in PEMWE systems pose a major challenge to the stability of electrocatalysts,and the development of efficient and corrosion-resistant catalysts is urgently needed.Currently,iridium(Ir)-based catalysts have gained great attention due to their promising activity and stability,while the extremely low reserves of Ir in the earth seriously hinder the commercialization of PEMWE.Therefore,a systematic understanding of the latest advances in Ir-based catalysts is necessary to guide their rational design to meet the industrial requirements.In this review,the general reaction mechanisms and advanced characterization techniques for mechanism recognition are first introduced.Afterwards,the systematic design strategies and performances of Ir-based catalysts,including metallic Ir,Ir oxides,and Ir-based perovskites,are summarized in detail.Finally,the conclusions,challenges,and prospects for Ir-based electrocatalysts are presented.展开更多
Sulfur-doped iron-cobalt tannate nanorods(S-FeCoTA)derived from metal-organic frameworks(MOFs)as electrocatalysts were synthesized via a one-step hydrothermal method.The optimized S-FeCoTA was interlaced by loose nano...Sulfur-doped iron-cobalt tannate nanorods(S-FeCoTA)derived from metal-organic frameworks(MOFs)as electrocatalysts were synthesized via a one-step hydrothermal method.The optimized S-FeCoTA was interlaced by loose nanorods,which had many voids.The S-FeCoTA catalysts exhibited excellent electrochemical oxygen evolution reaction(OER)performance with a low overpotential of 273 mV at 10 mA·cm^(-2)and a small Tafel slope of 36 mV·dec^(-1)in 1 mol·L^(-1)KOH.The potential remained at 1.48 V(vs RHE)at 10 mA·cm^(-2)under continuous testing for 15 h,implying that S-FeCoTA had good stability.The Faraday efficiency of S-FeCoTA was 94%.The outstanding OER activity of S-FeCoTA is attributed to the synergistic effects among S,Fe,and Co,thus promoting electron transfer,reducing the reaction kinetic barrier,and enhancing the OER performance.展开更多
Binary composites(ZIF-67/rGO)were synthesized by one-step precipitation method using cobalt nitrate hexahydrate as metal source,2-methylimidazole as organic ligand,and reduced graphene oxide(rGO)as carbon carrier.Then...Binary composites(ZIF-67/rGO)were synthesized by one-step precipitation method using cobalt nitrate hexahydrate as metal source,2-methylimidazole as organic ligand,and reduced graphene oxide(rGO)as carbon carrier.Then Ru3+was introduced for ion exchange,and the porous Ru-doped Co_(3)O_(4)/rGO(Ru-Co_(3)O_(4)/rGO)composite electrocatalyst was prepared by annealing.The phase structure,morphology,and valence state of the catalyst were analyzed by X-ray powder diffraction(XRD),scanning electron microscope(SEM),transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS).In 1 mol·L^(-1)KOH,the oxygen evolution reaction(OER)performance of the catalyst was measured by linear sweep voltammetry,cyclic voltammetry,and chronoamperometry.The results show that the combination of Ru doping and rGO provides a fast channel for collaborative electron transfer.At the same time,rGO as a carbon carrier can improve the electrical conductivity of Ru-Co_(3)O_(4)particles,and the uniformly dispersed nanoparticles enable the reactants to diffuse freely on the catalyst.The results showed that the electrochemical performance of Ru-Co_(3)O_(4)/rGO was much better than that of Co_(3)O_(4)/rGO,and the overpotential of Ru-Co_(3)O_(4)/rGO was 363.5 mV at the current density of 50 mA·cm^(-2).展开更多
The development of highly active, durable, and low-cost electrocatalysts is crucial for electrocatalytic hydrogen production. Ultrathin two-dimensional (2D) nanomaterials have extremely large specific surface areas, m...The development of highly active, durable, and low-cost electrocatalysts is crucial for electrocatalytic hydrogen production. Ultrathin two-dimensional (2D) nanomaterials have extremely large specific surface areas, making them highly desirable electrocatalyst morphologies. Medium-entropy alloys (MEAs) exhibit compositional tunability and entropy-driven structural stability, making them ideal electrocatalyst candidates. In this study, MoCoNi MEA with ultrathin 2D morphology was successfully developed using a facile ionic lay-er epitaxial method. The ultrathin 2D MoCoNi MEA showed an excellent oxygen evolution reaction (OER) electrocatalytic performance, with a low overpotential of 167 mV at a current density of 10 mA/cm^(2) and small Tafel slope of 33.2 mV/dec. At the overpotential of 167 mV, the ultrathin 2D MoCoNi MEA exhibited ultrahigh mass activity of 3359.6 A/g, which is three orders of magnitude higher than that of the commercial noble metal oxide RuO_(2) (1.15 A/g). This excellent electrocatalytic performance was attributed to the synergy of multiple active metal-induced medium entropies, as well as the ultrathin thickness, which considerably shortened the charge-transfer dis-tance and thus significantly promoted charge transfer. Owing to the natural entropy-stabilizing effect, the ultrathin 2D MoCoNi MEA maintained 90% of the initial current after a continuous OER electrocatalytic test for 134 h, showing impressive electrocatalytic stability. This study opens new avenues for the development of high-performance and low-cost electrocatalyst materials by creating MEAs with ultrathin 2D morphology.展开更多
Oxygen evolution reaction(OER)is often regarded as a crucial bottleneck in the field of renewable energy storage and conversion.To further accelerate the sluggish kinetics of OER,a cation and anion modulation strategy...Oxygen evolution reaction(OER)is often regarded as a crucial bottleneck in the field of renewable energy storage and conversion.To further accelerate the sluggish kinetics of OER,a cation and anion modulation strategy is reported here,which has been proven to be effective in preparing highly active electrocatalyst.For example,the cobalt,sulfur,and phosphorus modulated nickel hydroxide(denoted as NiCoPSOH)only needs an overpotential of 232 mV to reach a current density of 20 mA cm^(–2),demonstrating excellent OER performances.The cation and anion modulation facilitates the generation of high-valent Ni species,which would activate the lattice oxygen and switch the OER reaction pathway from conventional adsorbate evolution mechanism to lattice oxygen mechanism(LOM),as evidenced by the results of electrochemical measurements,Raman spectroscopy and differential electrochemical mass spectrometry.The LOM pathway of NiCoPSOH is further verified by the theoretical calculations,including the upshift of O 2p band center,the weakened Ni–O bond and the lowest energy barrier of rate-limiting step.Thus,the anion and cation modulated catalyst NiCoPSOH could effectively accelerate the sluggish OER kinetics.Our work provides a new insight into the cation and anion modulation,and broadens the possibility for the rational design of highly active electrocatalysts.展开更多
Catalyst–support interaction plays a crucial role in improving the catalytic activity of oxygen evolution reaction(OER).Here we modulate the catalyst–support interaction in polyaniline-supported Ni_(3)Fe oxide(Ni_(3...Catalyst–support interaction plays a crucial role in improving the catalytic activity of oxygen evolution reaction(OER).Here we modulate the catalyst–support interaction in polyaniline-supported Ni_(3)Fe oxide(Ni_(3)Fe oxide/PANI)with a robust hetero-interface,which significantly improves oxygen evolution activities with an overpotential of 270 mV at 10 mA cm^(-2)and specific activity of 2.08 mA cm_(ECSA)^(-2)at overpotential of 300 mV,3.84-fold that of Ni_(3)Fe oxide.It is revealed that the catalyst–support interaction between Ni_(3)Fe oxide and PANI support enhances the Ni–O covalency via the interfacial Ni–N bond,thus promoting the charge and mass transfer on Ni_(3)Fe oxide.Considering the excellent activity and stability,rechargeable Zn-air batteries with optimum Ni_(3)Fe oxide/PANI are assembled,delivering a low charge voltage of 1.95 V to cycle for 400 h at 10 mA cm^(-2).The regulation of the effect of catalyst–support interaction on catalytic activity provides new possibilities for the future design of highly efficient OER catalysts.展开更多
Anion-exchange membrane water electrolyzers(AEMWEs)for green hydrogen production have received intensive attention due to their feasibility of using earth-abundant NiFe-based catalysts.By introducing a third metal int...Anion-exchange membrane water electrolyzers(AEMWEs)for green hydrogen production have received intensive attention due to their feasibility of using earth-abundant NiFe-based catalysts.By introducing a third metal into NiFe-based catalysts to construct asymmetrical M-NiFe units,the d-orbital and electronic structures can be adjusted,which is an important strategy to achieve sufficient oxygen evolution reaction(OER)performance in AEMWEs.Herein,the ternary NiFeM(M:La,Mo)catalysts featured with distinct M-NiFe units and varying d-orbitals are reported in this work.Experimental and theoretical calculation results reveal that the doping of La leads to optimized hybridization between d orbital in NiFeM and 2p in oxygen,resulting in enhanced adsorption strength of oxygen intermediates,and reduced rate-determining step energy barrier,which is responsible for the enhanced OER performance.More critically,the obtained NiFeLa catalyst only requires 1.58 V to reach 1 A cm^(−2) in an anion exchange membrane electrolyzer and demonstrates excellent long-term stability of up to 600 h.展开更多
Polymeric perylene diimide(PDI)has been evidenced as a good candidate for photocatalytic water oxidation,yet the origin of the photocatalytic oxygen evolution activity remains unclear and needs further exploration.Her...Polymeric perylene diimide(PDI)has been evidenced as a good candidate for photocatalytic water oxidation,yet the origin of the photocatalytic oxygen evolution activity remains unclear and needs further exploration.Herein,with crystal and atomic structures of the self-assembled PDI revealed from the X-ray diffraction pattern,the electronic structure is theoretically illustrated by the first-principles density functional theory calculations,suggesting the suitable band structure and the direct electronic transition for efficient photocatalytic oxygen evolution over PDI.It is confirmed that the carbonyl O atoms on the conjugation structure serve as the active sites for oxygen evolution reaction by the crystal orbital Hamiltonian group analysis.The calculations of reaction free energy changes indicate that the oxygen evolution reaction should follow the reaction pathway of H_(2)O→^(*)OH→^(*)O→^(*)OOH→^(*)O_(2)with an overpotential of 0.81 V.Through an in-depth theoretical computational analysis in the atomic and electronic structures,the origin of photocatalytic oxygen evolution activity for PDI is well illustrated,which would help the rational design and modification of polymeric photocatalysts for efficient oxygen evolution.展开更多
The development of highly active catalyst in pH-neutral media for oxygen evolution reaction(OER)is critical in the field of renewable energy storage and conversion.Nevertheless,the slow kinetics of proton-coupled elec...The development of highly active catalyst in pH-neutral media for oxygen evolution reaction(OER)is critical in the field of renewable energy storage and conversion.Nevertheless,the slow kinetics of proton-coupled electron transfer(PCET)hinders the overall OER efficiency.Herein,we report an ionic liquid(IL)modified CoSn(OH)_(6)nanocubes(denoted as CoS-n(OH)_(6)-IL),which could be prepared through a facile strategy.The modified IL would not change the structural character-istics of CoSn(OH)_(6),but could effectively regulate the local proton activity near the active sites.The CoSn(OH)_(6)-IL exhibited higher intrinsic OER performances than the pristine CoSn(OH)_(6)in neutral media.For example,the current density of CoS-n(OH)_(6)-IL at 1.8 V versus reversible hydrogen electrode(RHE)was about 4 times higher than that of CoSn(OH)_(6).According to the pH-dependent kinetic investigations,operando electrochemical impedance spectroscopic,chemical probe tests,and deuterium kinetic isotope effects,the interfacial layer of IL could be utilized as a proton transfer mediator to promote the proton transfer,which enhances the surface coverage of OER intermediates and reduces the activation barrier.Consequent-ly,the sluggish OER kinetics would be efficiently accelerated.This study provides a facile and effective strategy to facilitate the PCET processes and is beneficial to guide the rational design of OER electrocatalysts.展开更多
Through employing zeolitic imidazolate framework-67(ZIF-67)templates,the straightforward hydrother-mal and electrodeposition methods were applied to synthesize FeOOH@CoMoO_(4)heterostructure attached to the sur-face o...Through employing zeolitic imidazolate framework-67(ZIF-67)templates,the straightforward hydrother-mal and electrodeposition methods were applied to synthesize FeOOH@CoMoO_(4)heterostructure attached to the sur-face of nickel foam(NF).The specific structure of the as-prepared FeOOH@CoMoO_(4)/NF-400s provided pronounced porosity and extensive surface area,enhancing rapid electron transport and exposing abundant active sites to improve catalytic reactions.Furthermore,the introduction of FeOOH,which induces electron transfer from FeOOH to CoMoO_(4),confirms their strong electronic interaction,thereby leading to an accelerated surface catalytic reaction.Consequently,the constructed FeOOH@CoMoO_(4)/NF-400s heterostructure demonstrated exceptional oxygen evolu-tion reaction(OER)activity,requiring an overpotential of 199 mV to deliver the current density of 10 mA·cm^(-2),cou-pled with the superior Tafel slope value of 49.56 mV·dec^(-1)and outstanding stability over 20 h under the current densities of both 10 and 100 mA·cm^(-2).展开更多
Metal-free electrocatalysts for the oxygen evolution reaction(OER)are gaining attention for their low cost,high conductivity,and moderate catalytic performance.While trace metal interference in assynthesized catalysts...Metal-free electrocatalysts for the oxygen evolution reaction(OER)are gaining attention for their low cost,high conductivity,and moderate catalytic performance.While trace metal interference in assynthesized catalysts has been ruled out,the impact of trace metal contamination during electrochemical activation remains unexplored.This study demonstrates that anodic pretreatment in alkaline electrolytes enhances the catalytic performance of carbon cloth.Specifically,carbon cloth activated in 8 mol/L Na OH achieves a current density of 10 m A/cm^(2)with an overpotential of only 338 m V,comparable to metalbased OER catalysts.Electrochemical and spectroscopic analyses show the deposition of Fe Ni O_(x)H_(y)oxyhydroxides(0.19±0.06μg/cm^(2))on specific sites of the carbon substrate during activation.These nanoparticles contribute significantly to the catalytic activity,with a synergistic effect between Fe Ni O_(x)H_(y)and the carbon substrate.The turnover frequency(TOF)for Fe correlates with the amount of C=O groups on the carbon substrate,providing evidence for an interfacial synergistic effect.This work emphasizes the importance of considering trace metal effects in metal-free catalyst evaluation and offers insights for the design of more efficient carbon-based hybrid OER catalysts.展开更多
Designing efficient and stable electrocatalysts for the oxygen evolution reaction(OER)is of paramount importance for many energy-related technologies and devices.Herein,we propose a controlled oxidation pyrolysis stra...Designing efficient and stable electrocatalysts for the oxygen evolution reaction(OER)is of paramount importance for many energy-related technologies and devices.Herein,we propose a controlled oxidation pyrolysis strategy to develop carbonized polymer dots(CPDs)-modified Rh-doped RuO_(2)electrocatalyst(Rh-RuO_(2)/CPDs).CPDs act as structure-directing agents,facilitating the formation of small-sized RhRuO_(2)/CPDs nanoparticles and engineering them with abundant defective structures and stable Ru-O sites.The experimental results and theoretical simulation unravel that the modulation effect of CPDs and Rh doping can effectively regulate the electronic structure,valence state and morphology of active Ru-O sites,thereby enhancing the electron transfer at the active site interface and optimizing the chemisorption behavior of oxygen intermediates.The resultant Rh-RuO_(2)/CPDs demonstrates overpotentials of 168 and 197 mV at 10 mA/cm^(2)for OER in 0.5 mol/L H_(2)SO_(4)and 1.0 mol/L KOH solution,respectively,and longterm catalytic stability.展开更多
High-entropy(HE)design provides ample opportunities for accessing catalysts with unique physiochemical properties for advanced energy and environmental applications.Although a variety of multi-cationic high-entropy ma...High-entropy(HE)design provides ample opportunities for accessing catalysts with unique physiochemical properties for advanced energy and environmental applications.Although a variety of multi-cationic high-entropy materials(HEMs)have been identified,HEMs consisted of multiple cationic and anionic elements are still limited.Herein,we present the design and synthesis of a series of rutile-structured high-entropy oxy fluorides(HEOFs),including[RuO_(2)]_(x)[MgMnZnCoF_(2)]_(y),[MnO_(2)]_(x)[MgMnZnCoF_(2)]_(y),[MoO_(2)]_(x)[MgMnZnCoF_(2)]_(y),[SnO_(2)]_(x)[MgMnZnCoF_(2)]_(y)and[TiO_(2)]_(x)[MgMnZnCoF_(2)]_(y)(x:y=3:1,2:1,1:1).All the HEOFs are obtained through mechanochemical alloying rutile-structured oxide and fluoride precursors and the HEOFs inherit the crystal structures of the skeleton oxides.Moreover,the HEOFs exhibit enhanced electrocatalytic oxygen evolution reaction(OER)activity than the corresponding oneelement precursors.Typically,the best-performed HEOF[RuO_(2)]_(3)[MgMnZnCoF_(2)]_(1)catalyst requires an overpotential of 240 mV to achieve a current density of 10 mA cm^(-2),which is lower than RuO_(2)(291 mV),More impressively,the specific mass activity of[RuO_(2)]_(3)[MgMnZnCoF_(2)]_(1)is 537.1 A g_(Ru)^(-1)at1.55 V(vs RHE),which is ca.7.6 times that of RuO_(2)(70.5 A g_(Ru)^(-1)).The enhanced electrocata lytic OER performance obtained on[RuO_(2)]_(3)[MgMnZnCoF_(2)]_(1)is ascribed to the contribution of the different cationic and anionic elements that modulates the electronic structures of the pristine RuO_(2),which facilitates efficient OER kinetics.This work demonstrates the efficacy of high-entropy design towards approaching excellent catalysts for enhanced electrocatalysis.展开更多
Transition metal(oxy)hydroxides are potential oxygen evolution reaction(OER)electrocatalysts;however,simultaneously modulating multiple factors to enhance their performance is a grand challenge.Here,we report an incor...Transition metal(oxy)hydroxides are potential oxygen evolution reaction(OER)electrocatalysts;however,simultaneously modulating multiple factors to enhance their performance is a grand challenge.Here,we report an incorporating heteroatom strategy via one-step hydrothermal approach to adjust more than one factor of Mn-doped NiFe(oxy)hydroxide(Mn-NiFeOOH/LDH)heterojunction.Mn doping regulates heterojunction morphology(reducing nanoparticles and becoming thinner and denser nanosheets),Ni/Fe ratio and valence states(Ni^(2+),Ni^(3+),and Ni^(3+Δ))of Ni ions.The former could effectively increase surface active sites,and the latter two reduce the content of Fe in the Mnx-NiFeOOH/LDH heterojunction,en-abling more Ni^(2+)convert to Ni^(3+/3+Δ)that have higher intrinsic OER activity.As a result,the first-rank Mn-NiFeOOH/LDH with ultra-low overpotential of 185 mV@20 mA cm^(-2) and 296 mV@500 mA cm^(-2),and the improved OER performance are outdo to those of commercial RuO_(2) catalyst for OER.Moreover,the Mn-NiFeOOH/LDH affords the earliest initial potential(1.392 V vs.RHE),corresponds to a recorded low overpotential(162 mV).Based on the density functional theory(DFT),Mn dopants can alter intermedi-ate adsorption energy and effectively decrease∗OOH’s energy barrier.This research exhibits a feasible strategy to design low cost electrocatalysts and provide new possibilities for future industrialization.展开更多
Oxygen evolution reaction(OER),a critical half-reaction in photocatalytic overall water splitting for producing hydrogen,is a key step toward sustainable energy conversion.Conventional photocatalysts often suffer from...Oxygen evolution reaction(OER),a critical half-reaction in photocatalytic overall water splitting for producing hydrogen,is a key step toward sustainable energy conversion.Conventional photocatalysts often suffer from limited light absorption and rapid charge recombination,hindering their further applications.To address these challenges,we have designed and synthesized a novel series of self-sensitized metal-organic frameworks(MOFs),Fe_(2)MCDDB(M=Ni,Mn,or Co).By incorporating photosensitive ligands,we have achieved efficient charge separation and promoted the transfer of photogenerated electrons to the active metal sites for water oxidation.Among the series,Fe_(2)NiCDDB exhibits exceptional OER activity,achieving an oxygen evolution rate of 125.3μmol g^(−1)h^(−1)under visible light irradiation.Experimental and theoretical results reveal that the optimized electronic structure and prolonged excited-state lifetime of Fe_(2)NiCDDB contribute to its enhanced catalytic performance.This work provides a promising strategy for designing two-in-one MOF photocatalysts for water oxidation.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
Industrial high-current-density oxygen evolution catalyst is the key to accelerating the practical application of hydrogen energy.Herein,Co_(9)S_(8)/CoS heterojunctions were rationally encapsulated in S,N-codoped carb...Industrial high-current-density oxygen evolution catalyst is the key to accelerating the practical application of hydrogen energy.Herein,Co_(9)S_(8)/CoS heterojunctions were rationally encapsulated in S,N-codoped carbon((Co_(9)S_(8)/CoS)@SNC)microleaf arrays,which are rooted on S-doped carbonized wood fibers(SCWF).Benefiting from the synergistic electronic interactions on heterointerfaces and the accelerated mass transfer by array structure,the obtained self-supporting(Co_(9)S_(8)/CoS)@SNC/SCWF electrode exhibits superior performance toward alkaline oxygen evolution reaction(OER)with an ultra-low overpotential of 274 mV at 1000 mA/cm^(2),a small Tafel slope of 48.84 mV/dec,and ultralong stability up to 100 h.Theoretical calculations show that interfacing Co_(9)S_(8)with CoS can upshift the d-band center of the Co atoms and strengthen the interactions with oxygen intermediates,thereby favoring OER performance.Furthermore,the(Co_(9)S_(8)/CoS)@SNC/SCWF electrode shows outstanding rechargeability and stable cycle life in aqueous Zn-air batteries with a peak power density of 201.3 mW/cm^(2),exceeding the commercial RuO_(2)and Pt/C hybrid catalysts.This work presents a promising strategy for the design of high-current-density OER electrocatalysts from sustainable wood fiber resources,thus promoting their practical applications in the field of electrochemical energy storage and conversion.展开更多
The harsh corrosive environment and sluggish oxygen evolution reaction(OER)kinetics at the anode of proton exchange membrane water electrolysis(PEMWE)cells warrant the use of excess Ir,thereby hindering large-scale in...The harsh corrosive environment and sluggish oxygen evolution reaction(OER)kinetics at the anode of proton exchange membrane water electrolysis(PEMWE)cells warrant the use of excess Ir,thereby hindering large-scale industrialization.To mitigate these issues,the present study aimed at fabricating a robust low-Ir-loading electrode via one-pot synthesis for efficient PEMWE.The pre-electrode was first prepared by alloying through the co-electrodeposition of Ir and Co,followed by the fabrication of Ir–Co oxide(Co-incorporated Ir oxide)electrodes via electrochemical dealloying.Two distinct dealloying techniques resulted in a modified valence state of Ir,and the effects of Co incorporation on the activity and stability of the OER catalysts were clarified using density functional theory(DFT)calculations,which offered theoretical insights into the reaction mechanism.While direct experimental validation of the oxygen evolution mechanism remains challenging under the current conditions,DFT-based theoretical modeling provided valuable perspectives on how Co incorporation could influence key steps in oxygen evolution catalysis.The Ir–Co oxide electrode with a selectively modulated valence state showed impressive performance with an overpotential of 258 mV at 10 mA cm^(−2),a low Tafel slope of 29.4 mV dec^(−1),and stability for 100 h at 100 mA cm^(−2)in the OER,in addition to a low overpotential of 16 mV at−10 mA cm^(−2)and high stability for 24 h in the hydrogen evolution reaction.The PEMWE cell equipped with the bifunctional Ir–Co oxide electrode as the anode and cathode exhibited outstanding performance(11.4 A cm^(−2)at 2.3 Vcell)despite having a low noble-metal content of 0.4 mgNM cm^(−2).展开更多
文摘The poor electrical conductivity of metal-organic frameworks(MOFs)limits their electrocatalytic performance in the oxygen evolution reaction(OER).In this study,a Py@Co-MOF composite material based on pyrene(Py)molecules and{[Co2(BINDI)(DMA)_(2)]·DMA}_(n)(Co-MOF,H4BINDI=N,N'-bis(5-isophthalic acid)naphthalenediimide,DMA=N,N-dimethylacetamide)was synthesized via a one-pot method,leveragingπ-πinteractions between pyrene and Co-MOF to modulate electrical conductivity.Results demonstrate that the Py@Co-MOF catalyst exhibited significantly enhanced OER performance compared to pure Co-MOF or pyrene-based electrodes,achieving an overpotential of 246 mV at a current density of 10 mA·cm^(-2) along with excellent stability.Density functional theory(DFT)calculations reveal that the formation of O*in the second step is the rate-determining step(RDS)during the OER process on Co-MOF,with an energy barrier of 0.85 eV due to the weak adsorption affinity of the OH*intermediate for Co sites.CCDC:2419276.
文摘A composite electrocatalyst,CoMoNiO-S/NF-110(NF is nickel foam),was synthesized through electrodeposition,followed by pyrolysis and then the vulcanization process.CoMoNiO-S/NF-110 exhibited a structure where Ni3S2 and Mo2S3 nanoparticles were integrated at the edges of Co3O4 nanosheets,creating a rich,heterogeneous interface that enhances the synergistic effects of each component.In an alkaline electrolyte,the synthesized CoMoNiO-S/NF-110 exhibited superior electrocatalytic performance for oxygen evolution reaction(OER),achieving current densities of 100 and 200 mA·cm^(-2) with low overpotentials of 199.4 and 224.4 mV,respectively,outperforming RuO2 and several high-performance Mo and Ni-based catalysts.This excellent performance is attributed to the rich interface formed between the components and active sites exposed by the defect structure.
基金supported by the National Natural Science Foundation of China(22202053,22109035,52362031,and 52274297)the start-up Research Foundation of Hainan University(KYQD(ZR)-20008,20083,20084,23068,and 23169)+4 种基金the Hainan Province Science and Technology Special Fund(ZDYF2024SHFZ074)the Collaborative Innovation Center of Marine Science and Technology,Hainan University(XTCX2022HYC04)the specific research fund of The Innovation Platform for Academicians of Hainan Province(YSPTZX202315)the Research Fund Program of Guangdong Provincial Key Laboratory of Fuel Cell Technology(FC202307)the Open Fund Project of Key Laboratory of Electrochemical Energy Storage and Energy Conversion in Hainan Province of China(KFKT2023002)。
文摘Hydrogen production from water electrolysis,in particular from proton exchange membrane water electrolyzers(PEMWE),is a key approach to realizing a carbon-free energy cycle.However,the high anodic potential and strong acid in PEMWE systems pose a major challenge to the stability of electrocatalysts,and the development of efficient and corrosion-resistant catalysts is urgently needed.Currently,iridium(Ir)-based catalysts have gained great attention due to their promising activity and stability,while the extremely low reserves of Ir in the earth seriously hinder the commercialization of PEMWE.Therefore,a systematic understanding of the latest advances in Ir-based catalysts is necessary to guide their rational design to meet the industrial requirements.In this review,the general reaction mechanisms and advanced characterization techniques for mechanism recognition are first introduced.Afterwards,the systematic design strategies and performances of Ir-based catalysts,including metallic Ir,Ir oxides,and Ir-based perovskites,are summarized in detail.Finally,the conclusions,challenges,and prospects for Ir-based electrocatalysts are presented.
文摘Sulfur-doped iron-cobalt tannate nanorods(S-FeCoTA)derived from metal-organic frameworks(MOFs)as electrocatalysts were synthesized via a one-step hydrothermal method.The optimized S-FeCoTA was interlaced by loose nanorods,which had many voids.The S-FeCoTA catalysts exhibited excellent electrochemical oxygen evolution reaction(OER)performance with a low overpotential of 273 mV at 10 mA·cm^(-2)and a small Tafel slope of 36 mV·dec^(-1)in 1 mol·L^(-1)KOH.The potential remained at 1.48 V(vs RHE)at 10 mA·cm^(-2)under continuous testing for 15 h,implying that S-FeCoTA had good stability.The Faraday efficiency of S-FeCoTA was 94%.The outstanding OER activity of S-FeCoTA is attributed to the synergistic effects among S,Fe,and Co,thus promoting electron transfer,reducing the reaction kinetic barrier,and enhancing the OER performance.
文摘Binary composites(ZIF-67/rGO)were synthesized by one-step precipitation method using cobalt nitrate hexahydrate as metal source,2-methylimidazole as organic ligand,and reduced graphene oxide(rGO)as carbon carrier.Then Ru3+was introduced for ion exchange,and the porous Ru-doped Co_(3)O_(4)/rGO(Ru-Co_(3)O_(4)/rGO)composite electrocatalyst was prepared by annealing.The phase structure,morphology,and valence state of the catalyst were analyzed by X-ray powder diffraction(XRD),scanning electron microscope(SEM),transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS).In 1 mol·L^(-1)KOH,the oxygen evolution reaction(OER)performance of the catalyst was measured by linear sweep voltammetry,cyclic voltammetry,and chronoamperometry.The results show that the combination of Ru doping and rGO provides a fast channel for collaborative electron transfer.At the same time,rGO as a carbon carrier can improve the electrical conductivity of Ru-Co_(3)O_(4)particles,and the uniformly dispersed nanoparticles enable the reactants to diffuse freely on the catalyst.The results showed that the electrochemical performance of Ru-Co_(3)O_(4)/rGO was much better than that of Co_(3)O_(4)/rGO,and the overpotential of Ru-Co_(3)O_(4)/rGO was 363.5 mV at the current density of 50 mA·cm^(-2).
基金supported by the Fundamental Research Funds for the Central Universities(No.2024JBZY008)National Natural Science Foundation of China(No.52401031)+1 种基金the Talent Fund of Beijing Jiaotong University,China(No.2024XKRC064)the National College Students Innovative Entrepreneurial Training Program(No.202510004157).
文摘The development of highly active, durable, and low-cost electrocatalysts is crucial for electrocatalytic hydrogen production. Ultrathin two-dimensional (2D) nanomaterials have extremely large specific surface areas, making them highly desirable electrocatalyst morphologies. Medium-entropy alloys (MEAs) exhibit compositional tunability and entropy-driven structural stability, making them ideal electrocatalyst candidates. In this study, MoCoNi MEA with ultrathin 2D morphology was successfully developed using a facile ionic lay-er epitaxial method. The ultrathin 2D MoCoNi MEA showed an excellent oxygen evolution reaction (OER) electrocatalytic performance, with a low overpotential of 167 mV at a current density of 10 mA/cm^(2) and small Tafel slope of 33.2 mV/dec. At the overpotential of 167 mV, the ultrathin 2D MoCoNi MEA exhibited ultrahigh mass activity of 3359.6 A/g, which is three orders of magnitude higher than that of the commercial noble metal oxide RuO_(2) (1.15 A/g). This excellent electrocatalytic performance was attributed to the synergy of multiple active metal-induced medium entropies, as well as the ultrathin thickness, which considerably shortened the charge-transfer dis-tance and thus significantly promoted charge transfer. Owing to the natural entropy-stabilizing effect, the ultrathin 2D MoCoNi MEA maintained 90% of the initial current after a continuous OER electrocatalytic test for 134 h, showing impressive electrocatalytic stability. This study opens new avenues for the development of high-performance and low-cost electrocatalyst materials by creating MEAs with ultrathin 2D morphology.
文摘Oxygen evolution reaction(OER)is often regarded as a crucial bottleneck in the field of renewable energy storage and conversion.To further accelerate the sluggish kinetics of OER,a cation and anion modulation strategy is reported here,which has been proven to be effective in preparing highly active electrocatalyst.For example,the cobalt,sulfur,and phosphorus modulated nickel hydroxide(denoted as NiCoPSOH)only needs an overpotential of 232 mV to reach a current density of 20 mA cm^(–2),demonstrating excellent OER performances.The cation and anion modulation facilitates the generation of high-valent Ni species,which would activate the lattice oxygen and switch the OER reaction pathway from conventional adsorbate evolution mechanism to lattice oxygen mechanism(LOM),as evidenced by the results of electrochemical measurements,Raman spectroscopy and differential electrochemical mass spectrometry.The LOM pathway of NiCoPSOH is further verified by the theoretical calculations,including the upshift of O 2p band center,the weakened Ni–O bond and the lowest energy barrier of rate-limiting step.Thus,the anion and cation modulated catalyst NiCoPSOH could effectively accelerate the sluggish OER kinetics.Our work provides a new insight into the cation and anion modulation,and broadens the possibility for the rational design of highly active electrocatalysts.
基金Research Institute for Smart Energy(CDB2)the grant from the Research Institute for Advanced Manufacturing(CD8Z)+4 种基金the grant from the Carbon Neutrality Funding Scheme(WZ2R)at The Hong Kong Polytechnic Universitysupport from the Hong Kong Polytechnic University(CD9B,CDBZ and WZ4Q)the National Natural Science Foundation of China(22205187)Shenzhen Municipal Science and Technology Innovation Commission(JCYJ20230807140402006)Start-up Foundation for Introducing Talent of NUIST and Natural Science Foundation of Jiangsu Province of China(BK20230426).
文摘Catalyst–support interaction plays a crucial role in improving the catalytic activity of oxygen evolution reaction(OER).Here we modulate the catalyst–support interaction in polyaniline-supported Ni_(3)Fe oxide(Ni_(3)Fe oxide/PANI)with a robust hetero-interface,which significantly improves oxygen evolution activities with an overpotential of 270 mV at 10 mA cm^(-2)and specific activity of 2.08 mA cm_(ECSA)^(-2)at overpotential of 300 mV,3.84-fold that of Ni_(3)Fe oxide.It is revealed that the catalyst–support interaction between Ni_(3)Fe oxide and PANI support enhances the Ni–O covalency via the interfacial Ni–N bond,thus promoting the charge and mass transfer on Ni_(3)Fe oxide.Considering the excellent activity and stability,rechargeable Zn-air batteries with optimum Ni_(3)Fe oxide/PANI are assembled,delivering a low charge voltage of 1.95 V to cycle for 400 h at 10 mA cm^(-2).The regulation of the effect of catalyst–support interaction on catalytic activity provides new possibilities for the future design of highly efficient OER catalysts.
基金financially supported by the National Natural Science Foundation of China(22309137,22279095)Open subject project State Key Laboratory of New Textile Materials and Advanced Processing Technologies(FZ2023001).
文摘Anion-exchange membrane water electrolyzers(AEMWEs)for green hydrogen production have received intensive attention due to their feasibility of using earth-abundant NiFe-based catalysts.By introducing a third metal into NiFe-based catalysts to construct asymmetrical M-NiFe units,the d-orbital and electronic structures can be adjusted,which is an important strategy to achieve sufficient oxygen evolution reaction(OER)performance in AEMWEs.Herein,the ternary NiFeM(M:La,Mo)catalysts featured with distinct M-NiFe units and varying d-orbitals are reported in this work.Experimental and theoretical calculation results reveal that the doping of La leads to optimized hybridization between d orbital in NiFeM and 2p in oxygen,resulting in enhanced adsorption strength of oxygen intermediates,and reduced rate-determining step energy barrier,which is responsible for the enhanced OER performance.More critically,the obtained NiFeLa catalyst only requires 1.58 V to reach 1 A cm^(−2) in an anion exchange membrane electrolyzer and demonstrates excellent long-term stability of up to 600 h.
基金supported by National Natural Science Foundation of China(No.523B2070,No.52225606).
文摘Polymeric perylene diimide(PDI)has been evidenced as a good candidate for photocatalytic water oxidation,yet the origin of the photocatalytic oxygen evolution activity remains unclear and needs further exploration.Herein,with crystal and atomic structures of the self-assembled PDI revealed from the X-ray diffraction pattern,the electronic structure is theoretically illustrated by the first-principles density functional theory calculations,suggesting the suitable band structure and the direct electronic transition for efficient photocatalytic oxygen evolution over PDI.It is confirmed that the carbonyl O atoms on the conjugation structure serve as the active sites for oxygen evolution reaction by the crystal orbital Hamiltonian group analysis.The calculations of reaction free energy changes indicate that the oxygen evolution reaction should follow the reaction pathway of H_(2)O→^(*)OH→^(*)O→^(*)OOH→^(*)O_(2)with an overpotential of 0.81 V.Through an in-depth theoretical computational analysis in the atomic and electronic structures,the origin of photocatalytic oxygen evolution activity for PDI is well illustrated,which would help the rational design and modification of polymeric photocatalysts for efficient oxygen evolution.
基金supported by the National Natural Science Foundation of China(22209040,22202063).
文摘The development of highly active catalyst in pH-neutral media for oxygen evolution reaction(OER)is critical in the field of renewable energy storage and conversion.Nevertheless,the slow kinetics of proton-coupled electron transfer(PCET)hinders the overall OER efficiency.Herein,we report an ionic liquid(IL)modified CoSn(OH)_(6)nanocubes(denoted as CoS-n(OH)_(6)-IL),which could be prepared through a facile strategy.The modified IL would not change the structural character-istics of CoSn(OH)_(6),but could effectively regulate the local proton activity near the active sites.The CoSn(OH)_(6)-IL exhibited higher intrinsic OER performances than the pristine CoSn(OH)_(6)in neutral media.For example,the current density of CoS-n(OH)_(6)-IL at 1.8 V versus reversible hydrogen electrode(RHE)was about 4 times higher than that of CoSn(OH)_(6).According to the pH-dependent kinetic investigations,operando electrochemical impedance spectroscopic,chemical probe tests,and deuterium kinetic isotope effects,the interfacial layer of IL could be utilized as a proton transfer mediator to promote the proton transfer,which enhances the surface coverage of OER intermediates and reduces the activation barrier.Consequent-ly,the sluggish OER kinetics would be efficiently accelerated.This study provides a facile and effective strategy to facilitate the PCET processes and is beneficial to guide the rational design of OER electrocatalysts.
文摘Through employing zeolitic imidazolate framework-67(ZIF-67)templates,the straightforward hydrother-mal and electrodeposition methods were applied to synthesize FeOOH@CoMoO_(4)heterostructure attached to the sur-face of nickel foam(NF).The specific structure of the as-prepared FeOOH@CoMoO_(4)/NF-400s provided pronounced porosity and extensive surface area,enhancing rapid electron transport and exposing abundant active sites to improve catalytic reactions.Furthermore,the introduction of FeOOH,which induces electron transfer from FeOOH to CoMoO_(4),confirms their strong electronic interaction,thereby leading to an accelerated surface catalytic reaction.Consequently,the constructed FeOOH@CoMoO_(4)/NF-400s heterostructure demonstrated exceptional oxygen evolu-tion reaction(OER)activity,requiring an overpotential of 199 mV to deliver the current density of 10 mA·cm^(-2),cou-pled with the superior Tafel slope value of 49.56 mV·dec^(-1)and outstanding stability over 20 h under the current densities of both 10 and 100 mA·cm^(-2).
基金financially supported by the National Natural Science Foundation of China(No.22479097)the Shanghai Science and Technology Committee(Nos.23ZR1433000 and 22511100400)+1 种基金the National High-Level Talent Program for Young Scholarsthe Start-up Fund(F.Song)from Shanghai Jiao Tong University。
文摘Metal-free electrocatalysts for the oxygen evolution reaction(OER)are gaining attention for their low cost,high conductivity,and moderate catalytic performance.While trace metal interference in assynthesized catalysts has been ruled out,the impact of trace metal contamination during electrochemical activation remains unexplored.This study demonstrates that anodic pretreatment in alkaline electrolytes enhances the catalytic performance of carbon cloth.Specifically,carbon cloth activated in 8 mol/L Na OH achieves a current density of 10 m A/cm^(2)with an overpotential of only 338 m V,comparable to metalbased OER catalysts.Electrochemical and spectroscopic analyses show the deposition of Fe Ni O_(x)H_(y)oxyhydroxides(0.19±0.06μg/cm^(2))on specific sites of the carbon substrate during activation.These nanoparticles contribute significantly to the catalytic activity,with a synergistic effect between Fe Ni O_(x)H_(y)and the carbon substrate.The turnover frequency(TOF)for Fe correlates with the amount of C=O groups on the carbon substrate,providing evidence for an interfacial synergistic effect.This work emphasizes the importance of considering trace metal effects in metal-free catalyst evaluation and offers insights for the design of more efficient carbon-based hybrid OER catalysts.
基金financially supported by the National Natural Science Foundation of China(No.22035001)the Natural Science Foundation of Jilin Province(No.***202402011)。
文摘Designing efficient and stable electrocatalysts for the oxygen evolution reaction(OER)is of paramount importance for many energy-related technologies and devices.Herein,we propose a controlled oxidation pyrolysis strategy to develop carbonized polymer dots(CPDs)-modified Rh-doped RuO_(2)electrocatalyst(Rh-RuO_(2)/CPDs).CPDs act as structure-directing agents,facilitating the formation of small-sized RhRuO_(2)/CPDs nanoparticles and engineering them with abundant defective structures and stable Ru-O sites.The experimental results and theoretical simulation unravel that the modulation effect of CPDs and Rh doping can effectively regulate the electronic structure,valence state and morphology of active Ru-O sites,thereby enhancing the electron transfer at the active site interface and optimizing the chemisorption behavior of oxygen intermediates.The resultant Rh-RuO_(2)/CPDs demonstrates overpotentials of 168 and 197 mV at 10 mA/cm^(2)for OER in 0.5 mol/L H_(2)SO_(4)and 1.0 mol/L KOH solution,respectively,and longterm catalytic stability.
基金financially supported by the National Natural Science Foundation of China(Grant No.22179015,21872142,22302026)the Liao Ning Revitalization Talents Program(XLYC1807196)+1 种基金the fund of the State Key Laboratory of Catalysis in DICP(N-22-06)the open fund of the State Key Laboratory of Molecular Reaction Dynamics in DICP,CAS(SKLMRD-K202414)。
文摘High-entropy(HE)design provides ample opportunities for accessing catalysts with unique physiochemical properties for advanced energy and environmental applications.Although a variety of multi-cationic high-entropy materials(HEMs)have been identified,HEMs consisted of multiple cationic and anionic elements are still limited.Herein,we present the design and synthesis of a series of rutile-structured high-entropy oxy fluorides(HEOFs),including[RuO_(2)]_(x)[MgMnZnCoF_(2)]_(y),[MnO_(2)]_(x)[MgMnZnCoF_(2)]_(y),[MoO_(2)]_(x)[MgMnZnCoF_(2)]_(y),[SnO_(2)]_(x)[MgMnZnCoF_(2)]_(y)and[TiO_(2)]_(x)[MgMnZnCoF_(2)]_(y)(x:y=3:1,2:1,1:1).All the HEOFs are obtained through mechanochemical alloying rutile-structured oxide and fluoride precursors and the HEOFs inherit the crystal structures of the skeleton oxides.Moreover,the HEOFs exhibit enhanced electrocatalytic oxygen evolution reaction(OER)activity than the corresponding oneelement precursors.Typically,the best-performed HEOF[RuO_(2)]_(3)[MgMnZnCoF_(2)]_(1)catalyst requires an overpotential of 240 mV to achieve a current density of 10 mA cm^(-2),which is lower than RuO_(2)(291 mV),More impressively,the specific mass activity of[RuO_(2)]_(3)[MgMnZnCoF_(2)]_(1)is 537.1 A g_(Ru)^(-1)at1.55 V(vs RHE),which is ca.7.6 times that of RuO_(2)(70.5 A g_(Ru)^(-1)).The enhanced electrocata lytic OER performance obtained on[RuO_(2)]_(3)[MgMnZnCoF_(2)]_(1)is ascribed to the contribution of the different cationic and anionic elements that modulates the electronic structures of the pristine RuO_(2),which facilitates efficient OER kinetics.This work demonstrates the efficacy of high-entropy design towards approaching excellent catalysts for enhanced electrocatalysis.
基金funding support by the Changsha Natural Science Foundation(grant no.kq2208023)National Natural Scientific Foundation of China(grant no.12074113).
文摘Transition metal(oxy)hydroxides are potential oxygen evolution reaction(OER)electrocatalysts;however,simultaneously modulating multiple factors to enhance their performance is a grand challenge.Here,we report an incorporating heteroatom strategy via one-step hydrothermal approach to adjust more than one factor of Mn-doped NiFe(oxy)hydroxide(Mn-NiFeOOH/LDH)heterojunction.Mn doping regulates heterojunction morphology(reducing nanoparticles and becoming thinner and denser nanosheets),Ni/Fe ratio and valence states(Ni^(2+),Ni^(3+),and Ni^(3+Δ))of Ni ions.The former could effectively increase surface active sites,and the latter two reduce the content of Fe in the Mnx-NiFeOOH/LDH heterojunction,en-abling more Ni^(2+)convert to Ni^(3+/3+Δ)that have higher intrinsic OER activity.As a result,the first-rank Mn-NiFeOOH/LDH with ultra-low overpotential of 185 mV@20 mA cm^(-2) and 296 mV@500 mA cm^(-2),and the improved OER performance are outdo to those of commercial RuO_(2) catalyst for OER.Moreover,the Mn-NiFeOOH/LDH affords the earliest initial potential(1.392 V vs.RHE),corresponds to a recorded low overpotential(162 mV).Based on the density functional theory(DFT),Mn dopants can alter intermedi-ate adsorption energy and effectively decrease∗OOH’s energy barrier.This research exhibits a feasible strategy to design low cost electrocatalysts and provide new possibilities for future industrialization.
基金funded by the National Natural Science Foundation of China(22271063 and 22371054)the Foundation of Basic and Applied Basic Research of Guangdong Province(2024A1515010423)+1 种基金Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01Z032)Science and Technology Planning Project of Guangdong Province(2021A0505030066).
文摘Oxygen evolution reaction(OER),a critical half-reaction in photocatalytic overall water splitting for producing hydrogen,is a key step toward sustainable energy conversion.Conventional photocatalysts often suffer from limited light absorption and rapid charge recombination,hindering their further applications.To address these challenges,we have designed and synthesized a novel series of self-sensitized metal-organic frameworks(MOFs),Fe_(2)MCDDB(M=Ni,Mn,or Co).By incorporating photosensitive ligands,we have achieved efficient charge separation and promoted the transfer of photogenerated electrons to the active metal sites for water oxidation.Among the series,Fe_(2)NiCDDB exhibits exceptional OER activity,achieving an oxygen evolution rate of 125.3μmol g^(−1)h^(−1)under visible light irradiation.Experimental and theoretical results reveal that the optimized electronic structure and prolonged excited-state lifetime of Fe_(2)NiCDDB contribute to its enhanced catalytic performance.This work provides a promising strategy for designing two-in-one MOF photocatalysts for water oxidation.
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supported by National Key Research and Development Program of China(No.2023YFD2200503)the Young Elite Scientists Sponsorship Program from National Forestry and Grassland Administration of China(No.2019132614)+1 种基金the Science and Technology Innovation Program of Hunan Province(Nos.2021RC3103 and 2022RC3054)the Scientific Research Project of Hunan Provincial Education Department(Nos.23B0276 and 21B0225).
文摘Industrial high-current-density oxygen evolution catalyst is the key to accelerating the practical application of hydrogen energy.Herein,Co_(9)S_(8)/CoS heterojunctions were rationally encapsulated in S,N-codoped carbon((Co_(9)S_(8)/CoS)@SNC)microleaf arrays,which are rooted on S-doped carbonized wood fibers(SCWF).Benefiting from the synergistic electronic interactions on heterointerfaces and the accelerated mass transfer by array structure,the obtained self-supporting(Co_(9)S_(8)/CoS)@SNC/SCWF electrode exhibits superior performance toward alkaline oxygen evolution reaction(OER)with an ultra-low overpotential of 274 mV at 1000 mA/cm^(2),a small Tafel slope of 48.84 mV/dec,and ultralong stability up to 100 h.Theoretical calculations show that interfacing Co_(9)S_(8)with CoS can upshift the d-band center of the Co atoms and strengthen the interactions with oxygen intermediates,thereby favoring OER performance.Furthermore,the(Co_(9)S_(8)/CoS)@SNC/SCWF electrode shows outstanding rechargeability and stable cycle life in aqueous Zn-air batteries with a peak power density of 201.3 mW/cm^(2),exceeding the commercial RuO_(2)and Pt/C hybrid catalysts.This work presents a promising strategy for the design of high-current-density OER electrocatalysts from sustainable wood fiber resources,thus promoting their practical applications in the field of electrochemical energy storage and conversion.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(RS-2024-00340074,RS-2024-00409901,2022M3I3A1081901,and RS-2024-00413272)。
文摘The harsh corrosive environment and sluggish oxygen evolution reaction(OER)kinetics at the anode of proton exchange membrane water electrolysis(PEMWE)cells warrant the use of excess Ir,thereby hindering large-scale industrialization.To mitigate these issues,the present study aimed at fabricating a robust low-Ir-loading electrode via one-pot synthesis for efficient PEMWE.The pre-electrode was first prepared by alloying through the co-electrodeposition of Ir and Co,followed by the fabrication of Ir–Co oxide(Co-incorporated Ir oxide)electrodes via electrochemical dealloying.Two distinct dealloying techniques resulted in a modified valence state of Ir,and the effects of Co incorporation on the activity and stability of the OER catalysts were clarified using density functional theory(DFT)calculations,which offered theoretical insights into the reaction mechanism.While direct experimental validation of the oxygen evolution mechanism remains challenging under the current conditions,DFT-based theoretical modeling provided valuable perspectives on how Co incorporation could influence key steps in oxygen evolution catalysis.The Ir–Co oxide electrode with a selectively modulated valence state showed impressive performance with an overpotential of 258 mV at 10 mA cm^(−2),a low Tafel slope of 29.4 mV dec^(−1),and stability for 100 h at 100 mA cm^(−2)in the OER,in addition to a low overpotential of 16 mV at−10 mA cm^(−2)and high stability for 24 h in the hydrogen evolution reaction.The PEMWE cell equipped with the bifunctional Ir–Co oxide electrode as the anode and cathode exhibited outstanding performance(11.4 A cm^(−2)at 2.3 Vcell)despite having a low noble-metal content of 0.4 mgNM cm^(−2).
