F-PbO2 electrode and polytetrafluoroethylene （PTFE） doped F-PbO2 electrode （PTFE-F-PbO2） were prepared on a plexiglas sheet substrate by a series of procedure including chemical and electrochemical depositions. Th...F-PbO2 electrode and polytetrafluoroethylene （PTFE） doped F-PbO2 electrode （PTFE-F-PbO2） were prepared on a plexiglas sheet substrate by a series of procedure including chemical and electrochemical depositions. The electrochemical activities of these two electrodes for oxygen evolution （OE） reaction were examined by electrochemical tests. In comparison with F-PbO2, PTFE-F-PbO2 electrode exhibited larger active surface area and higher oxygen vacancy deficiency, which resulted in its higher electrocatalytic activity for OE. In addition, both exchange current density and activation energy of the electrodes for OE were calculated in terms of active surface area. The values of exchange current density and activation energy in 0.5 mol·L^-1 H2SO4 aqueous solution were 1.125×10^ -3 mA·cm^-2 and 18.62 kJ·mol^-1 for PTFE-F-PbO2, and 8.384×10^-4 mA·cm^- 2 and 28.98 kJ·mol^-1 for F-PbO2, respectively. Because these values are calculated on the basis of the active surface areas of the electrodes, the enhanced activity of PTFE-F-PbO2 can be attributed to an increase in oxygen vacancy deficiency of PbO2 due to doping by PTFE. The influence of PTFE adulteration on the activity of PbO2 film electrode for OE was investigated in detail in this study.展开更多
In this study,we prepared Ti/IrO2–ZrO2 electrodes with different ZrO2 contents using zirconium-n-butoxide(C16H36O4Zr)and chloroiridic acid(H2IrCl6)via a sol–gel route.To explore the effect of ZrO2 content on the sur...In this study,we prepared Ti/IrO2–ZrO2 electrodes with different ZrO2 contents using zirconium-n-butoxide(C16H36O4Zr)and chloroiridic acid(H2IrCl6)via a sol–gel route.To explore the effect of ZrO2 content on the surface properties and electrochemical behavior of electrodes,we performed physical characterizations and electrochemical measurements.The obtained results revealed that the binary oxide coating was composed of rutile IrO2,amorphous ZrO2,and an IrO2–ZrO2 solid solution.The IrO2–ZrO2 binary oxide coatings exhibited cracked structures with flat regions.A slight incorporation of ZrO2 promoted the crystallization of the active component IrO2.However,the crystallization of IrO2 was hindered when the added ZrO2 content was greater than 30at%.The appropriate incorporation of ZrO2 enhanced the electrocatalytic performance of the pure IrO2 coating.The Ti/70at%IrO2–30at%ZrO2 electrode,with its large active surface area,improved electrocatalytic activity,long service lifetime,and especially,lower cost,is the most effective for promoting oxygen evolution in sulfuric acid solution.展开更多
IrO2 and IrRuOx(Ir:Ru 60:40 at%),supported by 50 wt%onto titania nanotubes(TNTs)and(3 at%Nb)Nb-doped titania nanotubes(Nb-TNTs),as electrocatalysts for the oxygen evolution reaction(OER),were synthesized and character...IrO2 and IrRuOx(Ir:Ru 60:40 at%),supported by 50 wt%onto titania nanotubes(TNTs)and(3 at%Nb)Nb-doped titania nanotubes(Nb-TNTs),as electrocatalysts for the oxygen evolution reaction(OER),were synthesized and characterized by means of structural,surface analytical and electrochemical techniques.Nb doping of titania significantly increased the surface area of the support from 145(TNTs)to 260 m2g-1(Nb-TNTs),which was significantly higher than those of the Nb-doped titania supports previously reported in the literature.The surface analytical techniques showed good dispersion of the catalysts onto the supports.The X-ray photoelectron spectroscopy analyses showed that Nb was mainly in the form of Nb(IV)species,the suitable form to behave as a donor introducing free electrons to the conduction band of titania.The redox transitions of the cyclic voltammograms,in agreement with the XPS results,were found to be reversible.Despite the supported materials presented bigger crystallite sizes than the unsupported ones,the total number of active sites of the former was also higher due to their better catalyst dispersion.Considering the outer and the total charges of the cyclic voltammograms in the range 0.1–1.4 V,stability and electrode potentials at given current densities,the preferred catalyst was Ir O2 supported on the Nb-TNTs.The electrode potentials corresponding to given current densities were between the smallest ones given in the literature despite the small oxide loading used in this work and its Nb doping,thus making the Nb-TNTs-supported IrO2 catalyst a promising candidate for the OER.The good dispersion of IrO2,high specific surface area of the Nb-doped supports,accessibility of the electroactive centers,increased stability due to Nb doping and electron donor properties of the Nb(IV)oxide species were considered the main reasons for its good performance.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
Herein, novel plasmonic Bi metal in situ deposited in reduced Ti O2 microspheres(Bi@R-Ti O2) are fabricated via a bimetallic MOF-derived synthesized strategy by adjusting the synthesizing temperature. Different charac...Herein, novel plasmonic Bi metal in situ deposited in reduced Ti O2 microspheres(Bi@R-Ti O2) are fabricated via a bimetallic MOF-derived synthesized strategy by adjusting the synthesizing temperature. Different characterization techniques, including XRD, SEM, TEM, XPS, DRS, PL, EIS, and photocurrent generation, are performed to investigate the structural and optical properties of the as-prepared samples. The results indicate that the Bi particles are generated inside and outside of reduced Ti O2 microspheres via the reduction of Ti4+ and Bi3+ by ethylene glycol. When the annealing temperature is controlled at 300 o C, the corresponding Bi@R-Ti O2-300 sample with an appropriate amount of Bi nanoparticles exhibits the highest full solar spectrum photocatalytic oxygen evolution activity(4728.709 μmol h–1 g–1), which is 5.9 and 9.5 times higher than that of pure Ti O2 and Bi-Ti bimetal organic frameworks(Bi-Ti-MOFs). Several reasons are suggested for the above results:(1) Bi metal behaves as an "electron acceptor" to accelerate the charge carrier transfer from Ti O2 to Bi;(2) The surface plasmon resonance effect of loaded metallic Bi particles can enhance the visible and NIR light absorption capacity;(3) The generation of Ti3+ further narrows the band gap of TiO2.展开更多
Ru@RuO2 core-shell nanorods were successfully synthesized by heat-treating Ru nanorods with air oxidation through an accurate control of the temperature and time. The structure, composition, dimension, and adsorption ...Ru@RuO2 core-shell nanorods were successfully synthesized by heat-treating Ru nanorods with air oxidation through an accurate control of the temperature and time. The structure, composition, dimension, and adsorption property of the core-shell nanorods were well characterized with XRD and TEM. The catalytic activity and stability were electrochemically evaluated with a rotating disk electrode, a rotating ring-disk electrode, and chronopotentiometric methods. The Ru@RuO2 nanorods reveal excellent bifunctional catalytic activity and robust stability for both oxygen evolution reaction(OER) and hydrogen evolution reaction(HER). The overpotentials for OER and HER are 320 m V and 137 m V at the current density of10 m A cm-2, respectively. The catalytic activity of Ru@RuO2 nanorods for OER is 6.5 times higher than that of the state-of-the-art catalyst IrO2 according to the catalytic current density measured at 1.60 V(versus RHE).The catalytic activity of Ru@RuO2 nanorods for HER is comparable to 40%Pt/C by comparing the catalytic current densities at à0.2 V.展开更多
Metal oxohydroxides(MOOH) are widely accepted as the true active species for oxygen evolution reaction(OER).However,the MOOH converted from precatalysts usually exhibits better catalytic performance than those directl...Metal oxohydroxides(MOOH) are widely accepted as the true active species for oxygen evolution reaction(OER).However,the MOOH converted from precatalysts usually exhibits better catalytic performance than those directly synthesized.The underlying structural reason for this phenomenon remains controversial.In this work,CoOOH and Co(OH)2with similar morphology are employed as model catalysts to investigate the origin of in-situ converted catalyst s high activity,as Co(OH)2can be fully converted to CoOOH during OER.In-situ Raman,electron paramagnetic resonance,HR-TEM,and X-ray spectroscopic studies reveal that O vacancies in the CoOOH converted from Co(OH)2play a key role in its higher intrinsic activity towards OER than directly synthesized CoOOH.Furthermore,theoretical calculations and electrochemical methods indicate that O vacancies in CoOOH affect the interaction between Co-O bond,downshift the d-band center of Co,further weaken the adsorption of OH*,and finally facilitate the OER process over CoOOH.This work not only provides a deep understanding of pre-catalyst's high OER activity by taking Co(OH)2as an example but also deliver insights into the activation process of other electrochemic al oxidation reactions.展开更多
Artificial carbon fixation is a promising pathway for achieving the carbon cycle and environment remediation.However,the sluggish kinetics of oxygen evolution reaction(OER)and poor selectivity of CO_(2) reduction seri...Artificial carbon fixation is a promising pathway for achieving the carbon cycle and environment remediation.However,the sluggish kinetics of oxygen evolution reaction(OER)and poor selectivity of CO_(2) reduction seriously limited the overall conversion efficiencies of solar energy to chemical fuels.Herein,we demonstrated a facile and feasible strategy to rationally regulate the coordination environment and electronic structure of surface-active sites on both photoanode and cathode.More specifically,the defect engineering has been employed to reduce the coordination number of ultrathin FeNi catalysts decorated on BiVO4 photoanodes,resulting in one of the highest OER activities of 6.51 mA cm^(−2)(1.23 VRHE,AM 1.5G).Additionally,single-atom cobalt(II)phthalocyanine anchoring on the N-rich carbon substrates to increase Co–N coordination number remarkably promotes CO_(2) adsorption and activation for high selective CO production.Their integration achieved a record activity of 109.4μmol cm^(−2) h−1 for CO production with a faradaic efficiency of>90%,and an outstanding solar conversion efficiency of 5.41%has been achieved by further integrating a photovoltaic utilizing the sunlight(>500 nm).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
This work is devoted to the development of a low cost dimensionally stable anode with high oxygen evolution catalytic activity for practical applications.For this purpose,a Ti/SnO_(x)/MnO_(2) anode was fabricated thro...This work is devoted to the development of a low cost dimensionally stable anode with high oxygen evolution catalytic activity for practical applications.For this purpose,a Ti/SnO_(x)/MnO_(2) anode was fabricated through an innovative strategy involving Sn electrodeposition,oxidation,and MnO_(2)-layer preparation.The structure of the anode was characterized,and the oxygen evolution performance was evaluated in a H_(2)SO_(4) solution.The results show that compared with the Ti/SnO_(2)/MnO_(2) anode prepared by the conventional brushing-annealing process,the Ti/SnO_(x)/MnO_(2) anode fabricated through the innovative procedure exhibits a lower oxygen evolution potential and a nearly 40%longer accelerated lifespan.The superior oxygen evolution performance of the Ti/SnO_(x)/MnO_(2) anode is attributed to the distinctive SnO_(x) intermediate layer fabricated through Sn electrodeposition followed by oxidation,which indicates the great potential of the anode as a dimensionally stable anode for metal electrowinning and hydrogen production by electrolysis,etc.展开更多
The oxygen evolution reaction(OER)has received widespread attention as an anodic reaction in various key electrochemical processes such as water splitting,carbon dioxide electroreduction,and ammonia electrosynthesis.T...The oxygen evolution reaction(OER)has received widespread attention as an anodic reaction in various key electrochemical processes such as water splitting,carbon dioxide electroreduction,and ammonia electrosynthesis.Therefore,there is an urgent need for efficient non-precious OER electrocatalysts to reduce the energy consumption and cost of these processes.NiFe layered double hydroxides(LDHs)with tunable electronic structure properties exhibit excellent OER intrinsic activity.However,their low electrical conductivity and tendency to agglomerate during electrocatalysis hinder their performance in OER.Herein,benefiting from the attraction of abundant negatively charged groups on the MXene surface towards Ni^(2+)and Fe^(3+),a heterostructure of highly conductive Mo_(2)CT_(x)MXene and NiFe alloy/LDH composite was prepared using a simple in-situ growth strategy.Combining experimental results and theoretical calculations,it is revealed that Mo_(2)CT_(x)MXene,as a substrate,significantly improves the OER performance of the NiFe-based catalyst by enhancing the electrical conductivity,mitigating the agglomeration,accelerating the oxidation and tuning the electronic structure.Consequently,in 1 M KOH electrolyte,the overpotential required to reach an OER current density of 10 mA cm^(-2)is only 230 mV,and the catalyst maintains high stability even after 3000 cyclic voltammetry cycles.This work expands the application of Mo_(2)CT_(x)MXene in electrocatalysis,and provides useful experience for the regulation of LDH-based electrocatalysts.展开更多
Activating both metal and lattice oxygen sites for efficient oxygen evolution reactions(OER)is a critical challenge.This study pioneers a novel approach,employing cobalt-nickel glycerate solid spheres(CoNi-G SSs)as se...Activating both metal and lattice oxygen sites for efficient oxygen evolution reactions(OER)is a critical challenge.This study pioneers a novel approach,employing cobalt-nickel glycerate solid spheres(CoNi-G SSs)as self-sacrificial templates to synthesize yolk-shell structured CoNi-G SSs@ZIF-67 nanospheres.The derived NiCo2S4@CoS2/MoS2 double-shelled hollow nanospheres integrate the adsorbate evolution mechanism(AEM)and lattice oxygen mechanism(LOM),enabling synergistic dual catalytic pathways.Nickel modulation facilitates active species reconstruction in NiCo_(2)S_(4),enhancing lattice oxygen activity and optimizing the LOM pathway.Characterization results indicate that anode activation triggered the redox processes of metal and lattice oxygen sites,involving the formation and re-filling of oxygen vacancies.Additionally,the CoS_(2)/MoS_(2) heterostructure enhances the AEM pathway,as supported by density functional theory calculations,which demonstrate optimized adsorption of intermediates for both hydrogen evolution reaction and OER.The assembled anion exchange membrane water splitting device can deliver a catalytic current of 500 mA cm^(-2) at 1.74 V under commercial catalytic operating conditions(1 mol L^(-1) KOH)for 150 h,with negligible degradation.This work provides important insights into the understanding of OER mechanisms and the design of high-performance water-splitting electrocatalysts,while also opening new avenues for developing multifunctional materials with multi-shell structures.展开更多
To overcome the sluggish kinetics and excessive overpotentials of the oxygen evolution reaction(OER),there is an imperative need for the development of highly efficient,cost-effective,and durable electrocatalysts.This...To overcome the sluggish kinetics and excessive overpotentials of the oxygen evolution reaction(OER),there is an imperative need for the development of highly efficient,cost-effective,and durable electrocatalysts.This study presents for the first time a strategy for in situ SO_(4)^(2−)regulation of HEMs.Unlike previous studies SO_(4)^(2−)is directly anchored to HEMs rather than formed through uncontrolled transformation or surface reconstruction.A series of novel electrocatalysts N@(ZrFeCoNiAl)O_(x)-SO_(4)[HE/NS-(0–4)]were prepared by the low-temperature NaBH4 reduction method.The content of SO_(4)^(2−)showed an inverse volcano relationship with the OER catalytic activity,all the samples exhibit excellent OER activity and remarkable stability over 50 h.The moderate introduction of SO_(4)^(2−)-oriented HE/NS-2 forms a short-range ordered and long-range disordered structure,which stably combines high catalytic activity and excellent electrical conductivity,exhibiting LOM-dominated OER mechanism with an overpotential of 257 mV at 10 mA cm^(−2)and a Tafel slope of 41.86 mV dec^(−1).The catalytic performance of the highly crystalline HE/NS-4 electrode(291 mV@10 mA cm^(−2))containing a large amount of SO_(4)^(2−)and the HE/NS-0(340 mV@10 mA cm^(−2))without SO_(4)^(2−)is both poor.SO_(4)^(2−)as the main promoting factor,controlling the growth of HEMs morphology,structural evolution,and the adjustment of the valence state of active metal sites,playing a vital role in activating lattice oxygen and promoting O–O coupling.N as an electron donor,further improves the electronic structure of HEMs.In situ Raman spectroscopy to probe the dynamic reconstruction of HE/NS-2,anion/cation leaching facilitates self-reconstruction,and the formed metal(oxy)hydroxide is considered the active center of OER.This study pioneers a novel avenue for the controlled synthesis of oxidized anion-adsorbed HEMs and enhancing OER catalytic activity.展开更多
A spinel oxide NiCo204 prepared by thermal decomposition is of very high activity for the oxygen evolution reaction(OER)in alkaline solution.The oxygen evolution overpotential on NiCo204 is 0.252-0.262V in 10 M NaOH s...A spinel oxide NiCo204 prepared by thermal decomposition is of very high activity for the oxygen evolution reaction(OER)in alkaline solution.The oxygen evolution overpotential on NiCo204 is 0.252-0.262V in 10 M NaOH solution at 343K and current density 100 mAcm^(-2).展开更多
Co3O4/SiO2 catalysts for CO oxidation were prepared by conventional incipient wetness impregnation followed by calcination at various temperatures. Their structures were char- acterized with X-ray diffraction （XRD）,...Co3O4/SiO2 catalysts for CO oxidation were prepared by conventional incipient wetness impregnation followed by calcination at various temperatures. Their structures were char- acterized with X-ray diffraction （XRD）, laser Raman spectroscopy, X-ray photoelectron spectroscopy （XPS）, temperature-programmed reduction （TPR） and X-ray absorption fine structure （XAFS） spectroscopy. Both XRD and Raman spectroscopy only detect the existence of Co3O4 crystallites in all catalysts. However, XPS results indicate that excess Co2＋ ions are present on the surface of Co3O4 in Co3O4（200）/Si02 as compared with bulk Co3O4. Meanwhile, TPR results suggest the presence of surface oxygen vacancies on Co3O4 in Co3O4（200）/SiO2, and XAFS results demonstrate that Co3O4 in Co3O4（200）/SIO2 contains excess Co2＋. Increasing calcination temperature results in oxidation of excess Co2＋ and the decrease of the concentration of surface oxygen vacancies, consequently the for- mation of stoichiometric Co3O4 on supported catalysts. Among all Co3O4/SiO2 catalysts, Co3O4（200）/SiO2 exhibits the best catalytic performance towards CO oxidation, demonstrating that excess Co2＋ and surface oxygen vacancies can enhance the catalytic activity of Co3O4 towards CO oxidation. These results nicely demonstrate the effect of calcination temperature on the structure and catalytic performance towards CO oxidation of silicasupported Co3O4 catalysts and highlight the important role of surface oxygen vacancies on Co3O4.展开更多
TiO2 nanosheets mainly exposed （001） facet were prepared through a hydrothermal process with HF as the morphology-directing agent. Ru and RuO2 species were loaded by photo-deposition methods to prepare the photocata...TiO2 nanosheets mainly exposed （001） facet were prepared through a hydrothermal process with HF as the morphology-directing agent. Ru and RuO2 species were loaded by photo-deposition methods to prepare the photocatalysts. The structural features of the catalysts were characterized by X-ray di raction, transmission electron microscopy, inductively cou-pled plasma atomic emission spectrum, and H2 Temperature-programmed reduction. The photocatalytic property was studied by the O2 evolution from water oxidation, which was examined with respect to the in uences of Ru contents as well as the oxidation and reduction treatments, suggesting the charge separation effect of the Ru species co-catalysts on di erent facets of TiO2 nanosheets. In contrast to Ru/TiO2 and RuO2/TiO2 with the single deposited co-catalyst, the optimized catalyst 0.5%Ru-1.0%RuO2/TiO2 with dual co-catalysts achieved a much improved catalytic performance, in terms of the synergetic effect of dual co-catalysts and the enhanced charge separation effect.展开更多
Water electrolysis technology holds the perfect promise of the hydrogen production,yet control of efficiency and rate of water electrolysis greatly relies on the availability of high-performance electrode materials fo...Water electrolysis technology holds the perfect promise of the hydrogen production,yet control of efficiency and rate of water electrolysis greatly relies on the availability of high-performance electrode materials for kinetic-sluggish oxygen evolution reaction(OER).Accordingly,substantial endeavors have been made to explore advanced electrode materials over the past decade.Recently,RuO_(2) and RuO_(2)-based materials have been demonstrated to be promising for OER due to their remarkable electrocatalytic activity and pH-universal application.Herein,the great achievements and progresses of this flourishing spot are comprehensively reviewed,which are started by a general description of OER to understand the reaction mechanism in detail.Subsequently,the key advantages and issues of RuO_(2) towards OER are also introduced,followed by proposing many advanced strategies for further promoting the electrocatalytic OER performance of RuO_(2).Finally,the daunting challenges and future progresses of RuO_(2) electrocatalysts toward practical water oxidation are highlighted,aiming to provide guidance for the fabrication of desirable RuO_(2)-based electrocatalysts toward OER.展开更多
Hetero-structure induced high performance catalyst for oxygen evolution reaction(OER)in the water splitting reaction has received increased attention.Herein,we demonstrated a novel catalyst system of NiSe_(2)-CoSe_(2)...Hetero-structure induced high performance catalyst for oxygen evolution reaction(OER)in the water splitting reaction has received increased attention.Herein,we demonstrated a novel catalyst system of NiSe_(2)-CoSe_(2)consisting of nanorods and nanoparticles for the efficient OER in the alkaline electrolyte.This catalyst system can be easily fabricated via a low-temperature selenization of the solvothermal synthesized NiCo(OH)x precursor and the unique morphology of hybrid nanorods and nanoparticles was found by the electron microscopy analysis.The high valence state of the metal species was indicated by X-ray photoelectron spectroscopy study and a strong electronic effect was found in the NiSe_(2)-CoSe_(2)catalyst system compared to their counterparts.As a result,NiSe_(2)-CoSe_(2)exhibited high catalytic performance with a low overpotential of 250 mV to reach 10 mA·cm^(-2)for OER in the alkaline solution.Furthermore,high catalytic stability and catalytic kinetics were also observed.The superior performance can be attributed to the high valence states of Ni and Co and their strong synergetic coupling effect between the nanorods and nanoparticles,which could accelerate the charge transfer and offer abundant electrocatalytic active sites.The current work offers an efficient hetero-structure catalyst system for OER,and the results are helpful for the catalysis understanding.展开更多
Developing efficient oxygen evolution reaction(OER) electrocatalysts such as transition metal sulfides(TMSs) is of great importance to advance renewable hydrogen fuel toward further practical applications.Herein,NiCoS...Developing efficient oxygen evolution reaction(OER) electrocatalysts such as transition metal sulfides(TMSs) is of great importance to advance renewable hydrogen fuel toward further practical applications.Herein,NiCoS_(2) nanoparticles well decorated on double-sided N-doped reduced graphene oxide sheets(NiCoS_(2)/rGO) are prepared from an Al-containing ternary NiCoAl-layered double hydroxide precursor(NiCoAl-LDH) grown on GO support as an OER electrocatalyst.The Al-confinementassisted sulfurization,followed by selective acid treatment,endows the resulting NiCoS_(2)/rGO composite with the advantages:well-dispersed NiCoS_(2) nanoparticles,dualsided rGO support,as well as a large specific surface area of 119.4 m^(2)·g^(-1) and meso-/macroporous size distribution.The NiCoS_(2)/rGO electrocatalyst exhibits an overpotential of 273 mV at 10 mA·cm^(-2) and a good stability of 24 h,which outperform those of the counterparts of NiS_(2)/rGO and CoS_(2)/rGO.The results of electrochemical active surface area and electrochemical impedance spectra experimentally provide convincing rationales of the information of active sites and good conductivity,both underpin the enhanced electrocatalytic performances.展开更多
The development of efficient oxygen evolution electrocatalysts with reduced noble metal uses is a critical challenge for the deployment of various advanced energy conversion technologies.Here,a series of lanthanide-co...The development of efficient oxygen evolution electrocatalysts with reduced noble metal uses is a critical challenge for the deployment of various advanced energy conversion technologies.Here,a series of lanthanide-contained 6H-perovskites with a formula of Ba3LnIr2〇9(Ln=lanthanides)are investigated as oxygen evolution electrocatalysts,whose active subunits(i.e.,face-sharing Ir〇6 dimers)can be regulated by the lanthanides in terms of catalytic activity.By using density functional theory(DFT)calculations,we establish the theoretical trend in activity for Ba3LnIr2〇96H-perovskites,the activity of which is correlated with the difference of adsorption free energy(△G〇-△Goh)between O*and OH*reaction intermediates.We further establish a volcano curve between△Go—△Goh and the calculated 0 p-band center Among the Ba3LnIr2〇96H-perovskites,Ba3Lalr2〇9 locates at the peak of volcano curve,and correspondingly is the most active electrocatalyst due to the optimal 0 p-band property.展开更多
基金Supported by the National Natural Science Foundation of China （20406019）.
文摘F-PbO2 electrode and polytetrafluoroethylene （PTFE） doped F-PbO2 electrode （PTFE-F-PbO2） were prepared on a plexiglas sheet substrate by a series of procedure including chemical and electrochemical depositions. The electrochemical activities of these two electrodes for oxygen evolution （OE） reaction were examined by electrochemical tests. In comparison with F-PbO2, PTFE-F-PbO2 electrode exhibited larger active surface area and higher oxygen vacancy deficiency, which resulted in its higher electrocatalytic activity for OE. In addition, both exchange current density and activation energy of the electrodes for OE were calculated in terms of active surface area. The values of exchange current density and activation energy in 0.5 mol·L^-1 H2SO4 aqueous solution were 1.125×10^ -3 mA·cm^-2 and 18.62 kJ·mol^-1 for PTFE-F-PbO2, and 8.384×10^-4 mA·cm^- 2 and 28.98 kJ·mol^-1 for F-PbO2, respectively. Because these values are calculated on the basis of the active surface areas of the electrodes, the enhanced activity of PTFE-F-PbO2 can be attributed to an increase in oxygen vacancy deficiency of PbO2 due to doping by PTFE. The influence of PTFE adulteration on the activity of PbO2 film electrode for OE was investigated in detail in this study.
基金financially supported by the National Natural Science Foundation of China (Nos. U1802253, 51974025 and 51674026)the Guangxi Innovation-Driven Development Project (No. AA18242042-1)+1 种基金the Beijing Natural Science Foundation of China (No. 2182040)the Fundamental Research Funds for the Central Universities (FRF22TT-19-001)
文摘In this study,we prepared Ti/IrO2–ZrO2 electrodes with different ZrO2 contents using zirconium-n-butoxide(C16H36O4Zr)and chloroiridic acid(H2IrCl6)via a sol–gel route.To explore the effect of ZrO2 content on the surface properties and electrochemical behavior of electrodes,we performed physical characterizations and electrochemical measurements.The obtained results revealed that the binary oxide coating was composed of rutile IrO2,amorphous ZrO2,and an IrO2–ZrO2 solid solution.The IrO2–ZrO2 binary oxide coatings exhibited cracked structures with flat regions.A slight incorporation of ZrO2 promoted the crystallization of the active component IrO2.However,the crystallization of IrO2 was hindered when the added ZrO2 content was greater than 30at%.The appropriate incorporation of ZrO2 enhanced the electrocatalytic performance of the pure IrO2 coating.The Ti/70at%IrO2–30at%ZrO2 electrode,with its large active surface area,improved electrocatalytic activity,long service lifetime,and especially,lower cost,is the most effective for promoting oxygen evolution in sulfuric acid solution.
文摘IrO2 and IrRuOx(Ir:Ru 60:40 at%),supported by 50 wt%onto titania nanotubes(TNTs)and(3 at%Nb)Nb-doped titania nanotubes(Nb-TNTs),as electrocatalysts for the oxygen evolution reaction(OER),were synthesized and characterized by means of structural,surface analytical and electrochemical techniques.Nb doping of titania significantly increased the surface area of the support from 145(TNTs)to 260 m2g-1(Nb-TNTs),which was significantly higher than those of the Nb-doped titania supports previously reported in the literature.The surface analytical techniques showed good dispersion of the catalysts onto the supports.The X-ray photoelectron spectroscopy analyses showed that Nb was mainly in the form of Nb(IV)species,the suitable form to behave as a donor introducing free electrons to the conduction band of titania.The redox transitions of the cyclic voltammograms,in agreement with the XPS results,were found to be reversible.Despite the supported materials presented bigger crystallite sizes than the unsupported ones,the total number of active sites of the former was also higher due to their better catalyst dispersion.Considering the outer and the total charges of the cyclic voltammograms in the range 0.1–1.4 V,stability and electrode potentials at given current densities,the preferred catalyst was Ir O2 supported on the Nb-TNTs.The electrode potentials corresponding to given current densities were between the smallest ones given in the literature despite the small oxide loading used in this work and its Nb doping,thus making the Nb-TNTs-supported IrO2 catalyst a promising candidate for the OER.The good dispersion of IrO2,high specific surface area of the Nb-doped supports,accessibility of the electroactive centers,increased stability due to Nb doping and electron donor properties of the Nb(IV)oxide species were considered the main reasons for its good performance.
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.
基金the National Natural Science Foundation of China(51872173 and 51772176)Taishan Scholarship of Young Scholars(tsqn201812068)+2 种基金Natural Science Foundation of Shandong Province(ZR2017JL020)Taishan Scholarship of Climbing Plan(tspd20161006)Key Research and Development Program of Shandong Province(2018GGX102028)~~
文摘Herein, novel plasmonic Bi metal in situ deposited in reduced Ti O2 microspheres(Bi@R-Ti O2) are fabricated via a bimetallic MOF-derived synthesized strategy by adjusting the synthesizing temperature. Different characterization techniques, including XRD, SEM, TEM, XPS, DRS, PL, EIS, and photocurrent generation, are performed to investigate the structural and optical properties of the as-prepared samples. The results indicate that the Bi particles are generated inside and outside of reduced Ti O2 microspheres via the reduction of Ti4+ and Bi3+ by ethylene glycol. When the annealing temperature is controlled at 300 o C, the corresponding Bi@R-Ti O2-300 sample with an appropriate amount of Bi nanoparticles exhibits the highest full solar spectrum photocatalytic oxygen evolution activity(4728.709 μmol h–1 g–1), which is 5.9 and 9.5 times higher than that of pure Ti O2 and Bi-Ti bimetal organic frameworks(Bi-Ti-MOFs). Several reasons are suggested for the above results:(1) Bi metal behaves as an "electron acceptor" to accelerate the charge carrier transfer from Ti O2 to Bi;(2) The surface plasmon resonance effect of loaded metallic Bi particles can enhance the visible and NIR light absorption capacity;(3) The generation of Ti3+ further narrows the band gap of TiO2.
基金the U.S.Department of the ArmyU.S.Army Materiel Command for supporting this work
文摘Ru@RuO2 core-shell nanorods were successfully synthesized by heat-treating Ru nanorods with air oxidation through an accurate control of the temperature and time. The structure, composition, dimension, and adsorption property of the core-shell nanorods were well characterized with XRD and TEM. The catalytic activity and stability were electrochemically evaluated with a rotating disk electrode, a rotating ring-disk electrode, and chronopotentiometric methods. The Ru@RuO2 nanorods reveal excellent bifunctional catalytic activity and robust stability for both oxygen evolution reaction(OER) and hydrogen evolution reaction(HER). The overpotentials for OER and HER are 320 m V and 137 m V at the current density of10 m A cm-2, respectively. The catalytic activity of Ru@RuO2 nanorods for OER is 6.5 times higher than that of the state-of-the-art catalyst IrO2 according to the catalytic current density measured at 1.60 V(versus RHE).The catalytic activity of Ru@RuO2 nanorods for HER is comparable to 40%Pt/C by comparing the catalytic current densities at à0.2 V.
基金financially supported by the financial support from Natural Science Foundation of China(No.22209129)the High-Level Innovation and Entrepreneurship Talent Project of Qinchuangyuan(No.QCYRCXM-2022-123)+3 种基金the Innovation Capability Support Program of Shaanxi(No.2023-CXTD-26)the financial support from the"Young Talent Support Plan''of Xi'an Jiaotong University(No.HG6J024)the financial support from China Postdoctoral Science Foundation 2024M752560Postdoctoral Fellowship Program of CPSF under Grant Number GZB20230574
文摘Metal oxohydroxides(MOOH) are widely accepted as the true active species for oxygen evolution reaction(OER).However,the MOOH converted from precatalysts usually exhibits better catalytic performance than those directly synthesized.The underlying structural reason for this phenomenon remains controversial.In this work,CoOOH and Co(OH)2with similar morphology are employed as model catalysts to investigate the origin of in-situ converted catalyst s high activity,as Co(OH)2can be fully converted to CoOOH during OER.In-situ Raman,electron paramagnetic resonance,HR-TEM,and X-ray spectroscopic studies reveal that O vacancies in the CoOOH converted from Co(OH)2play a key role in its higher intrinsic activity towards OER than directly synthesized CoOOH.Furthermore,theoretical calculations and electrochemical methods indicate that O vacancies in CoOOH affect the interaction between Co-O bond,downshift the d-band center of Co,further weaken the adsorption of OH*,and finally facilitate the OER process over CoOOH.This work not only provides a deep understanding of pre-catalyst's high OER activity by taking Co(OH)2as an example but also deliver insights into the activation process of other electrochemic al oxidation reactions.
基金supported by the National Natural Science Foundation of China(21832005,22072168,22002175)Major Program of the Lanzhou Institute of Chemical Physics,CAS(No.ZYFZFX-3)+1 种基金Major Science and Technology Projects in Gansu Province(22ZD6GA003)West Light Foundation of The Chinese Academy of Sciences(xbzg-zdsys-202209).
文摘Artificial carbon fixation is a promising pathway for achieving the carbon cycle and environment remediation.However,the sluggish kinetics of oxygen evolution reaction(OER)and poor selectivity of CO_(2) reduction seriously limited the overall conversion efficiencies of solar energy to chemical fuels.Herein,we demonstrated a facile and feasible strategy to rationally regulate the coordination environment and electronic structure of surface-active sites on both photoanode and cathode.More specifically,the defect engineering has been employed to reduce the coordination number of ultrathin FeNi catalysts decorated on BiVO4 photoanodes,resulting in one of the highest OER activities of 6.51 mA cm^(−2)(1.23 VRHE,AM 1.5G).Additionally,single-atom cobalt(II)phthalocyanine anchoring on the N-rich carbon substrates to increase Co–N coordination number remarkably promotes CO_(2) adsorption and activation for high selective CO production.Their integration achieved a record activity of 109.4μmol cm^(−2) h−1 for CO production with a faradaic efficiency of>90%,and an outstanding solar conversion efficiency of 5.41%has been achieved by further integrating a photovoltaic utilizing the sunlight(>500 nm).
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.
文摘This work is devoted to the development of a low cost dimensionally stable anode with high oxygen evolution catalytic activity for practical applications.For this purpose,a Ti/SnO_(x)/MnO_(2) anode was fabricated through an innovative strategy involving Sn electrodeposition,oxidation,and MnO_(2)-layer preparation.The structure of the anode was characterized,and the oxygen evolution performance was evaluated in a H_(2)SO_(4) solution.The results show that compared with the Ti/SnO_(2)/MnO_(2) anode prepared by the conventional brushing-annealing process,the Ti/SnO_(x)/MnO_(2) anode fabricated through the innovative procedure exhibits a lower oxygen evolution potential and a nearly 40%longer accelerated lifespan.The superior oxygen evolution performance of the Ti/SnO_(x)/MnO_(2) anode is attributed to the distinctive SnO_(x) intermediate layer fabricated through Sn electrodeposition followed by oxidation,which indicates the great potential of the anode as a dimensionally stable anode for metal electrowinning and hydrogen production by electrolysis,etc.
基金financially supported by the National Natural Science Foundation of China(No.22209049)Natural Science Foundation of Guangdong Province(No.2023A1515012804)Science and Technology Program of Guangzhou(No.2023A04J0674)。
文摘The oxygen evolution reaction(OER)has received widespread attention as an anodic reaction in various key electrochemical processes such as water splitting,carbon dioxide electroreduction,and ammonia electrosynthesis.Therefore,there is an urgent need for efficient non-precious OER electrocatalysts to reduce the energy consumption and cost of these processes.NiFe layered double hydroxides(LDHs)with tunable electronic structure properties exhibit excellent OER intrinsic activity.However,their low electrical conductivity and tendency to agglomerate during electrocatalysis hinder their performance in OER.Herein,benefiting from the attraction of abundant negatively charged groups on the MXene surface towards Ni^(2+)and Fe^(3+),a heterostructure of highly conductive Mo_(2)CT_(x)MXene and NiFe alloy/LDH composite was prepared using a simple in-situ growth strategy.Combining experimental results and theoretical calculations,it is revealed that Mo_(2)CT_(x)MXene,as a substrate,significantly improves the OER performance of the NiFe-based catalyst by enhancing the electrical conductivity,mitigating the agglomeration,accelerating the oxidation and tuning the electronic structure.Consequently,in 1 M KOH electrolyte,the overpotential required to reach an OER current density of 10 mA cm^(-2)is only 230 mV,and the catalyst maintains high stability even after 3000 cyclic voltammetry cycles.This work expands the application of Mo_(2)CT_(x)MXene in electrocatalysis,and provides useful experience for the regulation of LDH-based electrocatalysts.
文摘Activating both metal and lattice oxygen sites for efficient oxygen evolution reactions(OER)is a critical challenge.This study pioneers a novel approach,employing cobalt-nickel glycerate solid spheres(CoNi-G SSs)as self-sacrificial templates to synthesize yolk-shell structured CoNi-G SSs@ZIF-67 nanospheres.The derived NiCo2S4@CoS2/MoS2 double-shelled hollow nanospheres integrate the adsorbate evolution mechanism(AEM)and lattice oxygen mechanism(LOM),enabling synergistic dual catalytic pathways.Nickel modulation facilitates active species reconstruction in NiCo_(2)S_(4),enhancing lattice oxygen activity and optimizing the LOM pathway.Characterization results indicate that anode activation triggered the redox processes of metal and lattice oxygen sites,involving the formation and re-filling of oxygen vacancies.Additionally,the CoS_(2)/MoS_(2) heterostructure enhances the AEM pathway,as supported by density functional theory calculations,which demonstrate optimized adsorption of intermediates for both hydrogen evolution reaction and OER.The assembled anion exchange membrane water splitting device can deliver a catalytic current of 500 mA cm^(-2) at 1.74 V under commercial catalytic operating conditions(1 mol L^(-1) KOH)for 150 h,with negligible degradation.This work provides important insights into the understanding of OER mechanisms and the design of high-performance water-splitting electrocatalysts,while also opening new avenues for developing multifunctional materials with multi-shell structures.
基金financially supported by the Natural Science Foundation of Guangxi Province(No.2022GXNSFDA035062)the Director's Fund Project of Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology(No.2023Z011).
文摘To overcome the sluggish kinetics and excessive overpotentials of the oxygen evolution reaction(OER),there is an imperative need for the development of highly efficient,cost-effective,and durable electrocatalysts.This study presents for the first time a strategy for in situ SO_(4)^(2−)regulation of HEMs.Unlike previous studies SO_(4)^(2−)is directly anchored to HEMs rather than formed through uncontrolled transformation or surface reconstruction.A series of novel electrocatalysts N@(ZrFeCoNiAl)O_(x)-SO_(4)[HE/NS-(0–4)]were prepared by the low-temperature NaBH4 reduction method.The content of SO_(4)^(2−)showed an inverse volcano relationship with the OER catalytic activity,all the samples exhibit excellent OER activity and remarkable stability over 50 h.The moderate introduction of SO_(4)^(2−)-oriented HE/NS-2 forms a short-range ordered and long-range disordered structure,which stably combines high catalytic activity and excellent electrical conductivity,exhibiting LOM-dominated OER mechanism with an overpotential of 257 mV at 10 mA cm^(−2)and a Tafel slope of 41.86 mV dec^(−1).The catalytic performance of the highly crystalline HE/NS-4 electrode(291 mV@10 mA cm^(−2))containing a large amount of SO_(4)^(2−)and the HE/NS-0(340 mV@10 mA cm^(−2))without SO_(4)^(2−)is both poor.SO_(4)^(2−)as the main promoting factor,controlling the growth of HEMs morphology,structural evolution,and the adjustment of the valence state of active metal sites,playing a vital role in activating lattice oxygen and promoting O–O coupling.N as an electron donor,further improves the electronic structure of HEMs.In situ Raman spectroscopy to probe the dynamic reconstruction of HE/NS-2,anion/cation leaching facilitates self-reconstruction,and the formed metal(oxy)hydroxide is considered the active center of OER.This study pioneers a novel avenue for the controlled synthesis of oxidized anion-adsorbed HEMs and enhancing OER catalytic activity.
文摘A spinel oxide NiCo204 prepared by thermal decomposition is of very high activity for the oxygen evolution reaction(OER)in alkaline solution.The oxygen evolution overpotential on NiCo204 is 0.252-0.262V in 10 M NaOH solution at 343K and current density 100 mAcm^(-2).
文摘Co3O4/SiO2 catalysts for CO oxidation were prepared by conventional incipient wetness impregnation followed by calcination at various temperatures. Their structures were char- acterized with X-ray diffraction （XRD）, laser Raman spectroscopy, X-ray photoelectron spectroscopy （XPS）, temperature-programmed reduction （TPR） and X-ray absorption fine structure （XAFS） spectroscopy. Both XRD and Raman spectroscopy only detect the existence of Co3O4 crystallites in all catalysts. However, XPS results indicate that excess Co2＋ ions are present on the surface of Co3O4 in Co3O4（200）/Si02 as compared with bulk Co3O4. Meanwhile, TPR results suggest the presence of surface oxygen vacancies on Co3O4 in Co3O4（200）/SiO2, and XAFS results demonstrate that Co3O4 in Co3O4（200）/SIO2 contains excess Co2＋. Increasing calcination temperature results in oxidation of excess Co2＋ and the decrease of the concentration of surface oxygen vacancies, consequently the for- mation of stoichiometric Co3O4 on supported catalysts. Among all Co3O4/SiO2 catalysts, Co3O4（200）/SiO2 exhibits the best catalytic performance towards CO oxidation, demonstrating that excess Co2＋ and surface oxygen vacancies can enhance the catalytic activity of Co3O4 towards CO oxidation. These results nicely demonstrate the effect of calcination temperature on the structure and catalytic performance towards CO oxidation of silicasupported Co3O4 catalysts and highlight the important role of surface oxygen vacancies on Co3O4.
文摘TiO2 nanosheets mainly exposed （001） facet were prepared through a hydrothermal process with HF as the morphology-directing agent. Ru and RuO2 species were loaded by photo-deposition methods to prepare the photocatalysts. The structural features of the catalysts were characterized by X-ray di raction, transmission electron microscopy, inductively cou-pled plasma atomic emission spectrum, and H2 Temperature-programmed reduction. The photocatalytic property was studied by the O2 evolution from water oxidation, which was examined with respect to the in uences of Ru contents as well as the oxidation and reduction treatments, suggesting the charge separation effect of the Ru species co-catalysts on di erent facets of TiO2 nanosheets. In contrast to Ru/TiO2 and RuO2/TiO2 with the single deposited co-catalyst, the optimized catalyst 0.5%Ru-1.0%RuO2/TiO2 with dual co-catalysts achieved a much improved catalytic performance, in terms of the synergetic effect of dual co-catalysts and the enhanced charge separation effect.
基金the National Natural Science Foundation of China(Nos.51873136,52073199)Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.18KJA150008)+1 种基金Natural Science Foundation of Jiangsu Province(No.BK20181428)。
文摘Water electrolysis technology holds the perfect promise of the hydrogen production,yet control of efficiency and rate of water electrolysis greatly relies on the availability of high-performance electrode materials for kinetic-sluggish oxygen evolution reaction(OER).Accordingly,substantial endeavors have been made to explore advanced electrode materials over the past decade.Recently,RuO_(2) and RuO_(2)-based materials have been demonstrated to be promising for OER due to their remarkable electrocatalytic activity and pH-universal application.Herein,the great achievements and progresses of this flourishing spot are comprehensively reviewed,which are started by a general description of OER to understand the reaction mechanism in detail.Subsequently,the key advantages and issues of RuO_(2) towards OER are also introduced,followed by proposing many advanced strategies for further promoting the electrocatalytic OER performance of RuO_(2).Finally,the daunting challenges and future progresses of RuO_(2) electrocatalysts toward practical water oxidation are highlighted,aiming to provide guidance for the fabrication of desirable RuO_(2)-based electrocatalysts toward OER.
基金The work is supported by the National Natural Science Foundation of China(21972124)the Priority Academic Program Development of Jiangsu Higher Education Institution.the support of the Six Talent Peaks Project of Jiangsu Province(XCL-070-2018)。
文摘Hetero-structure induced high performance catalyst for oxygen evolution reaction(OER)in the water splitting reaction has received increased attention.Herein,we demonstrated a novel catalyst system of NiSe_(2)-CoSe_(2)consisting of nanorods and nanoparticles for the efficient OER in the alkaline electrolyte.This catalyst system can be easily fabricated via a low-temperature selenization of the solvothermal synthesized NiCo(OH)x precursor and the unique morphology of hybrid nanorods and nanoparticles was found by the electron microscopy analysis.The high valence state of the metal species was indicated by X-ray photoelectron spectroscopy study and a strong electronic effect was found in the NiSe_(2)-CoSe_(2)catalyst system compared to their counterparts.As a result,NiSe_(2)-CoSe_(2)exhibited high catalytic performance with a low overpotential of 250 mV to reach 10 mA·cm^(-2)for OER in the alkaline solution.Furthermore,high catalytic stability and catalytic kinetics were also observed.The superior performance can be attributed to the high valence states of Ni and Co and their strong synergetic coupling effect between the nanorods and nanoparticles,which could accelerate the charge transfer and offer abundant electrocatalytic active sites.The current work offers an efficient hetero-structure catalyst system for OER,and the results are helpful for the catalysis understanding.
基金financially supported by the National Natural Science Foundation of China(No.U1607128)。
文摘Developing efficient oxygen evolution reaction(OER) electrocatalysts such as transition metal sulfides(TMSs) is of great importance to advance renewable hydrogen fuel toward further practical applications.Herein,NiCoS_(2) nanoparticles well decorated on double-sided N-doped reduced graphene oxide sheets(NiCoS_(2)/rGO) are prepared from an Al-containing ternary NiCoAl-layered double hydroxide precursor(NiCoAl-LDH) grown on GO support as an OER electrocatalyst.The Al-confinementassisted sulfurization,followed by selective acid treatment,endows the resulting NiCoS_(2)/rGO composite with the advantages:well-dispersed NiCoS_(2) nanoparticles,dualsided rGO support,as well as a large specific surface area of 119.4 m^(2)·g^(-1) and meso-/macroporous size distribution.The NiCoS_(2)/rGO electrocatalyst exhibits an overpotential of 273 mV at 10 mA·cm^(-2) and a good stability of 24 h,which outperform those of the counterparts of NiS_(2)/rGO and CoS_(2)/rGO.The results of electrochemical active surface area and electrochemical impedance spectra experimentally provide convincing rationales of the information of active sites and good conductivity,both underpin the enhanced electrocatalytic performances.
文摘The development of efficient oxygen evolution electrocatalysts with reduced noble metal uses is a critical challenge for the deployment of various advanced energy conversion technologies.Here,a series of lanthanide-contained 6H-perovskites with a formula of Ba3LnIr2〇9(Ln=lanthanides)are investigated as oxygen evolution electrocatalysts,whose active subunits(i.e.,face-sharing Ir〇6 dimers)can be regulated by the lanthanides in terms of catalytic activity.By using density functional theory(DFT)calculations,we establish the theoretical trend in activity for Ba3LnIr2〇96H-perovskites,the activity of which is correlated with the difference of adsorption free energy(△G〇-△Goh)between O*and OH*reaction intermediates.We further establish a volcano curve between△Go—△Goh and the calculated 0 p-band center Among the Ba3LnIr2〇96H-perovskites,Ba3Lalr2〇9 locates at the peak of volcano curve,and correspondingly is the most active electrocatalyst due to the optimal 0 p-band property.
