Amorphous RuO_(x)(a-RuO_(x)) with disordered atomic arrangement and abundant coordinatively unsaturated Ru sites possesses high intrinsic electrocatalytic activity for oxygen evolution reaction (OER).However,the a-RuO...Amorphous RuO_(x)(a-RuO_(x)) with disordered atomic arrangement and abundant coordinatively unsaturated Ru sites possesses high intrinsic electrocatalytic activity for oxygen evolution reaction (OER).However,the a-RuO_(x)is prone to fast corrosion during OER in strong acid.Here we realized the stabilization of an ultrathin a-RuO_(x)layer via constructing heterointerface with crystalline a-MnO_(2)nanorods array (MnO_(2)@aRuO_(x)).Benefiting from the strong electronic interfacial interaction,the as-formed MnO_(2)@a-RuO_(x)electrocatalyst display an ultralow overpotential of 128 mV to reach 10 mA cm^(-2)and stable operation for over 100 h in 0.1 mol L^(-1)HClO_(4).The assembled proton exchange membrane(PEM) water electrolyzer reach 1 A cm^(-2)at applied cell voltage of 1.71 V.Extensive characterizations indicate the MnO_(2)substrate work as an electron donor pool to prevent the overoxidation of Ru sites and the OER proceeds in adsorbent evolution mechanism process without involving lattice oxygen.Our work provides a promising route to construct robust amorphous phase electrocatalysts.展开更多
A kind of ruthenium oxide with smaller particles and higher porosity was prepared by a sol-gel process with RuCl3·xH2O and NaHCO3 solution. Several details concerning this new material, including crystal structur...A kind of ruthenium oxide with smaller particles and higher porosity was prepared by a sol-gel process with RuCl3·xH2O and NaHCO3 solution. Several details concerning this new material, including crystal structure, particle size as functions of the temperature, and electrochemical properties were also reported. The optimal annealing temperature was 210 ℃ and the powder annealed at this temperature had a rate capacitance of 541 F/g. In addition, the rate capacitance of the composite electrode reached 802 F/g after 10% carbon black was added, much higher than any previously reported value. High energy density supercapacitors were built with the newly discovered electrode material. Energy densities as high as 67 J/g were obtained based on the RuO2·xH2O alone. By introducing the highly porous carbon black into the electrode, energy densities great than 100 J/g could be achieved. The power density of the capacitor was enhanced significantly.展开更多
Hydrous ruthenium oxide was formed by a new process. The precursor was obtained by mixing the aqueous solutions of RuCl3xH2O and NaHCO3. The addition of NaHCO3 led to the formation of an oxide with extremely fine RuO2...Hydrous ruthenium oxide was formed by a new process. The precursor was obtained by mixing the aqueous solutions of RuCl3xH2O and NaHCO3. The addition of NaHCO3 led to the formation of an oxide with extremely fine RuO2 particles forming a porous network structure in the oxide electrode. Polyethylene glycol was added as a controller to partly inhibit the sol-gel reaction. The rate capacitance of 530 F·g^-1 was measured for the powder formed at an optimal annealing temperature of 210℃. Several details concerning this new material, including crystal structure, particle size as a function of temperature, and electrochemical properties, were also reported. In addition, the rate capacitance of the composite electrode reached 800 F·g^-1 after carbon black was added. By using the modified electrode of a RuO2/carbon black composite electrode, the electrochemical capacitor exhibits high energy density and stable power characteristics. The values of specific energy and maximum specific power of 24 Wh·kg^-1 and 4 kW·kg^-1, respectively, are demonstrated for a cell voltage between 0 and 1 V.展开更多
The effect of chloride ions on a monoclinic ZrO2-supported RuOx （RuOx/m-ZrO2） catalyst with a Ru surface density of 0.3 Ru/nm2 was studied in the selective oxidation of methanol to methyl formate （MF） at a low tem...The effect of chloride ions on a monoclinic ZrO2-supported RuOx （RuOx/m-ZrO2） catalyst with a Ru surface density of 0.3 Ru/nm2 was studied in the selective oxidation of methanol to methyl formate （MF） at a low temperature of 373 K. The m-ZrO2 support was Cl-free, and Cl- ions were introduced into the RuOx/m-ZrO2 catalyst by impregnation with zirconium oxychloride or ammonium chloride and subsequent thermal treatment in air at 673 K. The structures of these catalysts were characterized by X-ray diffraction, Raman and X-ray photoelectron spectroscopies. Their reducibility was probed by temperature-programmed reduction in H2. The RuOx domains were present as highly dispersed Rut42- structure on m-ZrO2 with similar reducibility for the RuOx/m-ZrO2 samples irrespective of modification with or without Cl ions. Introduction of appropriate amounts of zirconium oxychloride into RuOx/m-ZrO2 led to a remarkable increase in the methanol oxidation rate and MF selectivity, whereas introduction of ammonium chloride or zirconyl nitrate significantly inhibited the catalytic performance of RuOx/m-ZrO2. The promoting effect of Cl- ions derived from zirconium oxychloride can be tentatively attributed to their roles in facilitating the adsorption of methanol and desorption of MF product or its intermediates. This finding provides novel insights into the promoting effect of Cl- ions on oxides-based catalysts for selective oxidation reactions.展开更多
Ruthenium oxide,which fabricated by radio frequency sputtering is used as the sensitive membrane,which shows that the pH sensitivity is very high and has a linear response in different buffer solutions.The pH electrod...Ruthenium oxide,which fabricated by radio frequency sputtering is used as the sensitive membrane,which shows that the pH sensitivity is very high and has a linear response in different buffer solutions.The pH electrode,which applies the structure of separative structure EGFET (Extended Gate Field Effect Transistor) insteads of the conventional gate ISFET (Ion Sensitive Field Effect Transistor) for reducing the cost of the fabrication and measurement.Unfortunately,the performance of the pH sensor was falsified by the drift and hysteresis.In addition,the total response is composed of the intrinsic response and drift,and the hysteresis effect combines the slow response with drift.Consequently,we would also investigate the drift in the buffer solutions and hysteresis effect in the different paths.In this way,the more accurate sensing properties are obtained by the RuO_x pH electrode.展开更多
Ru O2·n H2O film was deposited on tantalum foils by electrodeposition and heat treatment using Ru Cl3·3H2O as precursor.Surface morphology, composition change and cyclic voltammetry from precursor to amorpho...Ru O2·n H2O film was deposited on tantalum foils by electrodeposition and heat treatment using Ru Cl3·3H2O as precursor.Surface morphology, composition change and cyclic voltammetry from precursor to amorphous and crystalline RuO2·n H2O films were studied by X-ray diffractometer, Fourier transformation infrared spectrometer, differential thermal analyzer, scanning electron microscope and electrochemical analyzer, respectively. The results show that the precursor was transformed gradually from amorphous to crystalline phase with temperature. When heat treated at 300 °C for 2h, RuO2·n H2O electrode surface gains mass of2.5 mg/cm2 with specific capacitance of 782 F/g. Besides, it is found that the specific capacitance of the film decreased by roughly20% with voltage scan rate increasing from 5 to 250 m V/s.展开更多
Developing low-cost,highly active and robust electrocatalysts for acidic oxygen evolution reaction(OER)is a critical challenge facing the hydrogen-based energy delivery system.As a cheaper alternative to the benchmark...Developing low-cost,highly active and robust electrocatalysts for acidic oxygen evolution reaction(OER)is a critical challenge facing the hydrogen-based energy delivery system.As a cheaper alternative to the benchmark IrO_(2),RuO_(2)possesses higher OER catalytic activity but suffers from intrinsically low stability arising from Ru dissolution and lattice oxygen overoxidation.Herein,we report a high-vacuum annealing strategy to regulate the oxygen vacancy(Ov)concentration in RuO_(2),enabling the controllable modulation of the atomic local coordination structures of RuO_(2).At the optimal Ov level,the RuO_(2-x)-2 catalyst forms stable metallic Ru-Ru bonds while maintaining oxidized Ru-O moieties,achieving an ultralow overpotential of 169 mV at 10 mA·cm^(-2)and exceptional stability with 400-hour stable operation in 0.5 M H_(2)SO_(4).Operando X-ray absorption fine structure(XAFS)and attenuated total reflectance Fourier-transform infrared(ATR-FTIR)results reveal that the Ru-Ru and adjacent Ru-O sites synergistically activate the oxide pathway mechanism,circumventing the scaling relationship and minimizing the structural distortion during the OER.This work provides not only a facile approach to controllable modulate local structure of RuO_(2)but also insights into the synergistic effects between multiple active centers,which would greatly promote the further development of high-performance RuO_(2)-based OER electrocatalysts.展开更多
The“ship-in-a-bottle(SIB)”strategy offers a novel pathway for constructing hybrid nanocomposites that possess distinctive structural properties,making them ideal as functional materials.This strategy involves the co...The“ship-in-a-bottle(SIB)”strategy offers a novel pathway for constructing hybrid nanocomposites that possess distinctive structural properties,making them ideal as functional materials.This strategy involves the confinement of vip components within a host material,often leading to precisely controlled particle sizes and unconventional electronic structures that exhibit unique properties.Here,we used a metal-organic framework(CoNi-MOF-74)as the host material to trap ultrafine RuO_(x)nanoparticles with uniform sizes of approximately 1.3 nm within its microporous structure.The electronic structures of these RuO_(x)nanoparticles have been thoroughly analyzed through X-ray absorption spectroscopy(XAS)measurement.The synthesized RuO_(x)@NiCo-MOF-74 demonstrates superior performance for water oxidation,with an overpotential of only 254 mV to reach a current density of 10 mA·cm^(−2)in alkaline electrolyte,and shows a mass activity that is enhanced by a factor of 154(4332 vs.28.2 A·gRu^(−1))compared to commercial RuO_(2)under test conditions at 1.63 V(vs.RHE).This work provides a new perspective on synthesizing organic-inorganic hybrid materials with unique structural properties and superior catalytic performance.展开更多
Experimental results are presented which allow comparison of the electrochemical performance of RuO 2/Ti, Ru 0 3 Sn 0 7 O 2/Ti and Ru 0 3 V 0 7 O 2/Ti catalysts prepared on a titanium substrate by thermal decompositio...Experimental results are presented which allow comparison of the electrochemical performance of RuO 2/Ti, Ru 0 3 Sn 0 7 O 2/Ti and Ru 0 3 V 0 7 O 2/Ti catalysts prepared on a titanium substrate by thermal decomposition from respective precursors. The highest activity for chlorine evolution is observed on the Ru 0 3 V 0 7 O 2/Ti electrode, lower on Ru 0 3 Sn 0 7 O 2/Ti and least on RuO 2/Ti. Voltammograms obtained in the polarisable region are used to characterize the different electrodes. Further more an analysis of the catalytic activity and reaction kinetics of the developed electrodes in NaCl are presented.展开更多
Chemical oxidation is used to cut and unzip multi-walled carbon nanotubes in the transverse direction and the axial direction to form graphene oxide nanoribbon （GONR）. Ruthenium oxide/reduced graphene oxide nanoribb...Chemical oxidation is used to cut and unzip multi-walled carbon nanotubes in the transverse direction and the axial direction to form graphene oxide nanoribbon （GONR）. Ruthenium oxide/reduced graphene oxide nanoribbon composite （RuO2/rGONR） with a 72.5 wt% RuO2 loading is synthesized through an aqueous-phase reaction, in which GONR is served as starting material, followed by mild thermal treatment in ambient air. The resulting RuO2/rGONR composite achieves specific capacitance up to 677 F.g l at the current density of 1 A·g^-1 in three-electrode system using 1 mol·L^-1 H2SO4 as electrolyte. The resultant electrode exhibits an excellent rate capability （91.8% retention rate at 20 A·g^-1）. Especially, the symmetric supercapacitor assembled on the basis of RuO2/rGONR electrode delivers high energy density （16.2 Wh·kg^-1） even at the power density of 9885 W·kg^-1, which is very essential for supercapacitors.展开更多
The design of efficient Ru-based electrocatalysts with high intrinsic activities for acidic water oxidation is highly desirable and challenging for water splitting in proton exchange membrane electrolyzers.Here,for th...The design of efficient Ru-based electrocatalysts with high intrinsic activities for acidic water oxidation is highly desirable and challenging for water splitting in proton exchange membrane electrolyzers.Here,for the first time,we engineer the charge density of Ru(IV)by creating tensile strains in the RuO2 shell of Ru@RuO2 core-shell nanoparticles,viz.Ru@RuO2-L.High-resolution spectroscopic characterizations confirm the presence of av.6%tensile strain in Ru-O bonds,which results in an effective reduction of the Ru(IV)charge density.The resultant Ru^X+(4<X<5)active sites greatly accelerate the oxygen evolution reaction(OER)in an acidic electrolyte,leading to a remarkably low overpotential of 191 mV at 10 mA cm^-2.These values are lower than those for the benchmark RuO2 catalyst and are also among the lowest for efficient Ru-based electrocatalysts reported thus far.The specific activity and mass activity are also greatly enhanced 4.2-fold and 17.7-fold compared to those of RuO2,respectively.The acidic OER activity improvement is ascribed to the lowered adsorption energy of*OOH,owing to the reduced charge density of Ru(IV),and the rapid charge transport owing to the Ru core.Ru@RuO2-L also demonstrates high feasibility as the anode catalyst for the overall water splitting in acidic media.展开更多
RuO_(2) has been considered a potential alternative to commercial IrO_(2) for the oxygen evolution reaction(OER)due to its superior intrinsic activity.However,its inherent structure dissolution in acidic environments ...RuO_(2) has been considered a potential alternative to commercial IrO_(2) for the oxygen evolution reaction(OER)due to its superior intrinsic activity.However,its inherent structure dissolution in acidic environments restricts its commercial applications.In this study,we report a novel Pd-doped ruthenium oxide(Pd–RuO_(2))nanosheet catalyst that exhibits improved activity and stability through a synergistic effect of Pd modulation of Ru electronic structure and the two-dimensional structure.The catalyst exhibits excellent performance,achieving an overpotential of only 204 mVat a current density of 10 mA cm^(-2).Impressively,after undergoing 8000 cycles of cyclic voltammetry testing,the overpotential merely decreased by 5 mV.The PEM electrolyzer with Pd0.08Ru0.92O_(2) as an anode catalyst survived an almost 130 h operation at 200 mA cm^(-2).To elucidate the underlying mechanisms responsible for the enhanced stability,we conducted an X-ray photoelectron spectroscopy(XPS)analysis,which reveals that the electron transfer from Pd to Ru effectively circumvents the over-oxidation of Ru,thus playing a crucial role in enhancing the catalyst's stability.Furthermore,density functional theory(DFT)calculations provide compelling evidence that the introduction of Pd into RuO_(2) effectively modulates electron correlations and facilitates the electron transfer from Pd to Ru,thereby preventing the overoxidation of Ru.Additionally,the application of the two-dimensional structure effectively inhibited the aggregation and growth of nanoparticles,further bolstering the structural integrity of the catalyst.展开更多
Ammonia (NH_(3)) plays a key role in the agricultural fertilizer and commodity chemical industries and is useful for exploring hydrogen storage carriers.The electrochemical nitrogen reduction reaction (NRR) is receivi...Ammonia (NH_(3)) plays a key role in the agricultural fertilizer and commodity chemical industries and is useful for exploring hydrogen storage carriers.The electrochemical nitrogen reduction reaction (NRR) is receiving attention as an environmentally sustainable NH_(3) synthesis replacement for the traditional Haber–Bosch process owing to its near ambient reaction conditions (<100℃ and 1 atm).However,its NH_(3) yield and faradaic efficiency are extremely low because of the sluggish kinetics of N≡N bond dissociation and the hindrance from competitive hydrogen evolution.To overcome these challenges,we herein introduce a dual-functionalized ionic liquid (1-(4-hydroxybutyl)-3-methylimidazolium hydroxide[HOBIM]OH) for a highly dispersed ruthenium oxide electrocatalyst to achieve a biased NRR.The observed uniform distribution of RuO_(2) on the carbon fiber and increase in the surface area for N_(2) adsorption by limiting proton access can be attributed to the presence of imidazolium ions.Moreover,extensive N_(2) adsorption contributes to enhanced NRR selectivity with an NH_(3) yield of 3.0×10^(-10)mol cm^(-2)s^(-1)(91.8μg h^(-1)mg^(-1)) and a faradaic efficiency of 2.2%at-0.20 V_(RHE).We expect our observations to provide new insights into the design of effective electrode structures for electrochemical NH;synthesis.展开更多
Design of electrode materials for stable and efficient electrocatalytic oxidation of As(Ⅲ)in arsenic-contaminated groundwater poses a great challenge due to the rapid deactivation of catalysts resulting from the high...Design of electrode materials for stable and efficient electrocatalytic oxidation of As(Ⅲ)in arsenic-contaminated groundwater poses a great challenge due to the rapid deactivation of catalysts resulting from the high oxygen evolution potential(OEP)and considerable barrier to generating reactive oxygen species(ROS).Herein,an innovative TNAs/SnO_(2)/PEDOT/Fe(Ⅲ)-RuO_(2) multilayer electrode was synthesized by utilizing a PEDOT-coated SnO_(2) interlayer as a supportive framework to combine Fe-doped amorphous RuO_(2) catalytic layer with TiO_(2) nanotube array substrate.Such electrode exhibited high activity and sta-bility for the oxidation of As(Ⅲ)to As(V)due to the large surface area provided by the TiO_(2) nanotube arrays and the SnO_(2)/PEDOT interlayer for facilitating the growth of the catalytic layer.The electrochem-ically active surface area of the electrode reached as high as 31.7 mF/cm^(2).Impressively,the doping of Fe into RuO_(2) layer led to a remarkable increase in the OEP value to 3.12 V,which boosted the indirect oxidation process mediated by ROS at a lower potential to achieve the As(Ⅲ)oxidation ratio of 98.5%.DFT calculations revealed that the Fe-doped amorphous RuO_(2) weakened the adsorption strength of·OH and.SO4-intermediates and lowered the energy barrier for generating ROS.Combined with ESR results,the formation of·OH and·SC4-with strong oxidizing properties was fully verified,providing further evi-dence for the involvement of ROS as the main mediator of the oxidation mechanism of As(Ⅲ).This work may provide valuable perspectives into the design of catalytic layer structures and heteroatom doping modifications for composite-coated electrodes.展开更多
Organic semiconductors are promising candidates as photoactive layers for photoelectrodes used in photoelectrochemical(PEC)cells due to their excellent light absorption and efficient charge transport properties with t...Organic semiconductors are promising candidates as photoactive layers for photoelectrodes used in photoelectrochemical(PEC)cells due to their excellent light absorption and efficient charge transport properties with the help of interfacial materials.However,the use of multilayers will make the charge transfer mechanism more complicated and decrease the PEC performance of the photoelectrode caused by the increased contact resistance.In this work,a PM6:Y6 bulk heterojunction(BHJ)-based photocathode is fabricated for efficient PEC hydrogen evolution reaction(HER)in an acidic aqueous solution.With RuO_(2)as an interfacial modification layer,the photocathode with a simple structure(fluorine-doped tin oxide(FTO)/PM6:Y6/RuO_(2))generates a maximum photocurrent density up to-15 m A/cm^(2)at 0 V vs.reference hydrogen electrode(RHE),outperforming all previously reported BHJ-based photocathodes in terms of PEC performance.The highest ratiometric power-saved efficiency of 3.7%is achieved at 0.4 V vs.RHE.展开更多
Hollow core-shell structure nanomaterials have been broadly used in energy storage, catalysis, reactor,and other fields due to their unique characteristics, including the synergy between different materials,a large sp...Hollow core-shell structure nanomaterials have been broadly used in energy storage, catalysis, reactor,and other fields due to their unique characteristics, including the synergy between different materials,a large specific surface area, small density, large charge carrying capacity and so on. However, their synthesis processes were mostly complicated, and few researches reported one-step encapsulation of different valence states of precious metals in carbon-based materials. Hence, a novel hollow core-shell nanostructure electrode material, RuO_(2)@Ru/HCs, with a lower mass of ruthenium to reduce costs was constructed by one-step hydrothermal method with hard template and co-assembled strategy, consisting of RuO_(2) core and ruthenium nanoparticles(Ru NPs) in carbon shell. The Ru NPs were uniformly assembled in the carbon layer, which not only improved the electronic conductivity but also provided more active centers to enhance the pseudocapacitance. The RuO_(2) core further enhanced the material’s energy storage capacity. Excellent capacitance storage(318.5 F·g^(-1)at 0.5 A·g^(-1)), rate performance(64.4%) from 0.5 A·g^(-1)to 20 A·g^(-1), and cycling stability(92.3% retention after 5000 cycles) were obtained by adjusting Ru loading to 0.92%(mass). It could be attributed to the wider pore size distribution in the micropores which increased the transfer of electrons and protons. The symmetrical supercapacitor device based on RuO_(2)@Ru/HCs could successfully light up the LED lamp. Therefore, our work verified that interfacial modification of RuO_(2) and carbon could bring attractive insights into energy density for nextgeneration supercapacitors.展开更多
The acidic oxygen evolution reaction(OER)is central to water electrolysis using proton‐exchange membranes.However,even as benchmark catalysts in the acidic OER,Ru‐based catalysts still suffer from sluggish kinetics ...The acidic oxygen evolution reaction(OER)is central to water electrolysis using proton‐exchange membranes.However,even as benchmark catalysts in the acidic OER,Ru‐based catalysts still suffer from sluggish kinetics owing to the scaling relationship that arises from the traditional concerted proton‐electron transfer(CPET)process.Motivated by the knowledge that a charged surface may be favorable for accelerating the OER kinetics,we posited the incorporation of elements with pseudocapacitive properties into Ru‐based catalysts.Herein,we report a RuPbOx electrocatalyst for efficient and stable water oxidation in acid with a low overpotential of 191 mV to reach 10 mA cm^(−2) and a low Tafel slope of 39 mV dec^(−1).The combination of electrochemical analysis,X‐ray photoelectron spectroscopy,and in situ Raman spectroscopy demonstrated that the improved OER kinetics was associated with the formation of superoxide precursors on the strongly charged surface after Pb incorporation,indicating a non‐concerted proton‐electron transfer mechanism for the OER on RuPbOx.展开更多
The ruthenium oxide(RuO_x) thin film was prepared by using the R.F.sputtering system.The RuO_x pH-sensitive electrode possesses a nearly-Nernstian pH sensitivity(about 57 mV/pH).For the enzyme penicillinase was immobi...The ruthenium oxide(RuO_x) thin film was prepared by using the R.F.sputtering system.The RuO_x pH-sensitive electrode possesses a nearly-Nernstian pH sensitivity(about 57 mV/pH).For the enzyme penicillinase was immobilized directly onto a RuO_x pH-sensitive surface by 3-glycidoxypropyltrimethoxysilane(GPTS).Some characteristics of the biosensor, such as sensitivity,linear range,and drift,are investigated and the difference between penicillinase immobilized and without are compared.According to the time-constant model,we can extract the time constant and amplitude at the response curve of the drift.Subsequently,the extracted parameters were used to simulate the mechanism of the drift behavior.展开更多
Hydrous ruthenium oxide,RuO2·xH2O,was synthesized through a sol-gel reaction of ruthenium chloride aqueous solution.The annealed RuO2·xH2O powders are aggregate of very small particles in nano-size of 70-80 ...Hydrous ruthenium oxide,RuO2·xH2O,was synthesized through a sol-gel reaction of ruthenium chloride aqueous solution.The annealed RuO2·xH2O powders are aggregate of very small particles in nano-size of 70-80 nm and have abundant porous structure as observed by SEM.The effect of electrode thickness,PTFE binder and carbon black addition on the super-capacitive properties of thick RuO2·nH2O electrodes was investigated.At low scan rate of 5 mV/s,the specific capacitance of RuO2·xH2O (SCR,based on the weight of RuO2·xH2O only) for pure RuO2·xH2O and RuO2·xH2O-PTFE-CB electrodes can reach 665 F/g.Increasing electrode thickness and mixing PTFE into RuO2·xH2O lead to a degradation of SCR and rate capacity.By adding carbon black into RuO2·xH2O-PTFE mixture,the rate capacity of the thick electrode (RuO2·xH2O-PTFE-CB) can be improved close to the thick pure RuO2·xH2O electrode.However,mixing with PTFE and carbon black leads to a loss of the overall mass-specific capacitance.The reason for the dependence of SCR and rate capacity on electrode thickness,binder and carbon black addition was discussed based on the relation between the resistance and utilization rate of electrodes.展开更多
This paper reports that the growth of RuO2（110） thin layer growth on Ru（0001） has been investigated by means of scanning tunnelling microscope （STM）. The STM images showed a domain structure with three rotationa...This paper reports that the growth of RuO2（110） thin layer growth on Ru（0001） has been investigated by means of scanning tunnelling microscope （STM）. The STM images showed a domain structure with three rotational domains of RuO2（110） rotated by an angle of 120°. The as-grown RuO2（110） thin layer is expanded from the bulk-truncated RuO2（110） due to the large mismatch between RuO2（110） and the Ru（0001） substrate. The results also indicate that growth of RuO2（110） thin layer on the Ru（0001） substrate by oxidation tends first to formation of the Ru-O （oxygen） chains in the [001] direction of RuO2 （110）.展开更多
基金supported by the Fundamental Research Funds for the Central Universities (2232024Y-01)the National Natural Science Foundation of China (52225204, 52272289, 52173233 and 52402231)+3 种基金the Innovation Program of Shanghai Municipal Education Commission (2021-01-07-00-03-E00109)the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, Natural Science Foundation of Shanghai (23ZR1479200)“Shuguang Program” supported by Shanghai Education Development Foundation and Shanghai Municipal Education Commission (20SG33)the DHU Distinguished Young Professor Program (LZA2022001)。
文摘Amorphous RuO_(x)(a-RuO_(x)) with disordered atomic arrangement and abundant coordinatively unsaturated Ru sites possesses high intrinsic electrocatalytic activity for oxygen evolution reaction (OER).However,the a-RuO_(x)is prone to fast corrosion during OER in strong acid.Here we realized the stabilization of an ultrathin a-RuO_(x)layer via constructing heterointerface with crystalline a-MnO_(2)nanorods array (MnO_(2)@aRuO_(x)).Benefiting from the strong electronic interfacial interaction,the as-formed MnO_(2)@a-RuO_(x)electrocatalyst display an ultralow overpotential of 128 mV to reach 10 mA cm^(-2)and stable operation for over 100 h in 0.1 mol L^(-1)HClO_(4).The assembled proton exchange membrane(PEM) water electrolyzer reach 1 A cm^(-2)at applied cell voltage of 1.71 V.Extensive characterizations indicate the MnO_(2)substrate work as an electron donor pool to prevent the overoxidation of Ru sites and the OER proceeds in adsorbent evolution mechanism process without involving lattice oxygen.Our work provides a promising route to construct robust amorphous phase electrocatalysts.
文摘A kind of ruthenium oxide with smaller particles and higher porosity was prepared by a sol-gel process with RuCl3·xH2O and NaHCO3 solution. Several details concerning this new material, including crystal structure, particle size as functions of the temperature, and electrochemical properties were also reported. The optimal annealing temperature was 210 ℃ and the powder annealed at this temperature had a rate capacitance of 541 F/g. In addition, the rate capacitance of the composite electrode reached 802 F/g after 10% carbon black was added, much higher than any previously reported value. High energy density supercapacitors were built with the newly discovered electrode material. Energy densities as high as 67 J/g were obtained based on the RuO2·xH2O alone. By introducing the highly porous carbon black into the electrode, energy densities great than 100 J/g could be achieved. The power density of the capacitor was enhanced significantly.
文摘Hydrous ruthenium oxide was formed by a new process. The precursor was obtained by mixing the aqueous solutions of RuCl3xH2O and NaHCO3. The addition of NaHCO3 led to the formation of an oxide with extremely fine RuO2 particles forming a porous network structure in the oxide electrode. Polyethylene glycol was added as a controller to partly inhibit the sol-gel reaction. The rate capacitance of 530 F·g^-1 was measured for the powder formed at an optimal annealing temperature of 210℃. Several details concerning this new material, including crystal structure, particle size as a function of temperature, and electrochemical properties, were also reported. In addition, the rate capacitance of the composite electrode reached 800 F·g^-1 after carbon black was added. By using the modified electrode of a RuO2/carbon black composite electrode, the electrochemical capacitor exhibits high energy density and stable power characteristics. The values of specific energy and maximum specific power of 24 Wh·kg^-1 and 4 kW·kg^-1, respectively, are demonstrated for a cell voltage between 0 and 1 V.
基金supported by the National Natural Science Foundation of China(20825310 and 20973011)National Basic Research Project of China (2011CB201400 and 2011CB808700)
文摘The effect of chloride ions on a monoclinic ZrO2-supported RuOx （RuOx/m-ZrO2） catalyst with a Ru surface density of 0.3 Ru/nm2 was studied in the selective oxidation of methanol to methyl formate （MF） at a low temperature of 373 K. The m-ZrO2 support was Cl-free, and Cl- ions were introduced into the RuOx/m-ZrO2 catalyst by impregnation with zirconium oxychloride or ammonium chloride and subsequent thermal treatment in air at 673 K. The structures of these catalysts were characterized by X-ray diffraction, Raman and X-ray photoelectron spectroscopies. Their reducibility was probed by temperature-programmed reduction in H2. The RuOx domains were present as highly dispersed Rut42- structure on m-ZrO2 with similar reducibility for the RuOx/m-ZrO2 samples irrespective of modification with or without Cl ions. Introduction of appropriate amounts of zirconium oxychloride into RuOx/m-ZrO2 led to a remarkable increase in the methanol oxidation rate and MF selectivity, whereas introduction of ammonium chloride or zirconyl nitrate significantly inhibited the catalytic performance of RuOx/m-ZrO2. The promoting effect of Cl- ions derived from zirconium oxychloride can be tentatively attributed to their roles in facilitating the adsorption of methanol and desorption of MF product or its intermediates. This finding provides novel insights into the promoting effect of Cl- ions on oxides-based catalysts for selective oxidation reactions.
文摘Ruthenium oxide,which fabricated by radio frequency sputtering is used as the sensitive membrane,which shows that the pH sensitivity is very high and has a linear response in different buffer solutions.The pH electrode,which applies the structure of separative structure EGFET (Extended Gate Field Effect Transistor) insteads of the conventional gate ISFET (Ion Sensitive Field Effect Transistor) for reducing the cost of the fabrication and measurement.Unfortunately,the performance of the pH sensor was falsified by the drift and hysteresis.In addition,the total response is composed of the intrinsic response and drift,and the hysteresis effect combines the slow response with drift.Consequently,we would also investigate the drift in the buffer solutions and hysteresis effect in the different paths.In this way,the more accurate sensing properties are obtained by the RuO_x pH electrode.
基金Project(S2013040015492)supported by the Natural Science Foundation of Guangdong Province,ChinaProject(2007AA03Z240)supported by Hi-tech Research and Development Program of China
文摘Ru O2·n H2O film was deposited on tantalum foils by electrodeposition and heat treatment using Ru Cl3·3H2O as precursor.Surface morphology, composition change and cyclic voltammetry from precursor to amorphous and crystalline RuO2·n H2O films were studied by X-ray diffractometer, Fourier transformation infrared spectrometer, differential thermal analyzer, scanning electron microscope and electrochemical analyzer, respectively. The results show that the precursor was transformed gradually from amorphous to crystalline phase with temperature. When heat treated at 300 °C for 2h, RuO2·n H2O electrode surface gains mass of2.5 mg/cm2 with specific capacitance of 782 F/g. Besides, it is found that the specific capacitance of the film decreased by roughly20% with voltage scan rate increasing from 5 to 250 m V/s.
基金supported by the National Natural Science Foundation of China(Nos.92261119 and 52301293).
文摘Developing low-cost,highly active and robust electrocatalysts for acidic oxygen evolution reaction(OER)is a critical challenge facing the hydrogen-based energy delivery system.As a cheaper alternative to the benchmark IrO_(2),RuO_(2)possesses higher OER catalytic activity but suffers from intrinsically low stability arising from Ru dissolution and lattice oxygen overoxidation.Herein,we report a high-vacuum annealing strategy to regulate the oxygen vacancy(Ov)concentration in RuO_(2),enabling the controllable modulation of the atomic local coordination structures of RuO_(2).At the optimal Ov level,the RuO_(2-x)-2 catalyst forms stable metallic Ru-Ru bonds while maintaining oxidized Ru-O moieties,achieving an ultralow overpotential of 169 mV at 10 mA·cm^(-2)and exceptional stability with 400-hour stable operation in 0.5 M H_(2)SO_(4).Operando X-ray absorption fine structure(XAFS)and attenuated total reflectance Fourier-transform infrared(ATR-FTIR)results reveal that the Ru-Ru and adjacent Ru-O sites synergistically activate the oxide pathway mechanism,circumventing the scaling relationship and minimizing the structural distortion during the OER.This work provides not only a facile approach to controllable modulate local structure of RuO_(2)but also insights into the synergistic effects between multiple active centers,which would greatly promote the further development of high-performance RuO_(2)-based OER electrocatalysts.
基金supported by the National Key R&D Program of China(No.2020YFA0406202)the National Natural Science Foundation of China(Nos.22090042 and 22405017)Fundamental Research Funds for the Central Universities,China(No.FRF-BR-23-02B).
文摘The“ship-in-a-bottle(SIB)”strategy offers a novel pathway for constructing hybrid nanocomposites that possess distinctive structural properties,making them ideal as functional materials.This strategy involves the confinement of vip components within a host material,often leading to precisely controlled particle sizes and unconventional electronic structures that exhibit unique properties.Here,we used a metal-organic framework(CoNi-MOF-74)as the host material to trap ultrafine RuO_(x)nanoparticles with uniform sizes of approximately 1.3 nm within its microporous structure.The electronic structures of these RuO_(x)nanoparticles have been thoroughly analyzed through X-ray absorption spectroscopy(XAS)measurement.The synthesized RuO_(x)@NiCo-MOF-74 demonstrates superior performance for water oxidation,with an overpotential of only 254 mV to reach a current density of 10 mA·cm^(−2)in alkaline electrolyte,and shows a mass activity that is enhanced by a factor of 154(4332 vs.28.2 A·gRu^(−1))compared to commercial RuO_(2)under test conditions at 1.63 V(vs.RHE).This work provides a new perspective on synthesizing organic-inorganic hybrid materials with unique structural properties and superior catalytic performance.
文摘Experimental results are presented which allow comparison of the electrochemical performance of RuO 2/Ti, Ru 0 3 Sn 0 7 O 2/Ti and Ru 0 3 V 0 7 O 2/Ti catalysts prepared on a titanium substrate by thermal decomposition from respective precursors. The highest activity for chlorine evolution is observed on the Ru 0 3 V 0 7 O 2/Ti electrode, lower on Ru 0 3 Sn 0 7 O 2/Ti and least on RuO 2/Ti. Voltammograms obtained in the polarisable region are used to characterize the different electrodes. Further more an analysis of the catalytic activity and reaction kinetics of the developed electrodes in NaCl are presented.
基金Acknowledgement We gratefully acknowledge the financial support offered by the National Natural Science Foundation of China （Nos. 20963009 21163017 and 21563027） and Specialized Research Fund for the Doctoral Program of Higher Education（No. 20126203110001）.
文摘Chemical oxidation is used to cut and unzip multi-walled carbon nanotubes in the transverse direction and the axial direction to form graphene oxide nanoribbon （GONR）. Ruthenium oxide/reduced graphene oxide nanoribbon composite （RuO2/rGONR） with a 72.5 wt% RuO2 loading is synthesized through an aqueous-phase reaction, in which GONR is served as starting material, followed by mild thermal treatment in ambient air. The resulting RuO2/rGONR composite achieves specific capacitance up to 677 F.g l at the current density of 1 A·g^-1 in three-electrode system using 1 mol·L^-1 H2SO4 as electrolyte. The resultant electrode exhibits an excellent rate capability （91.8% retention rate at 20 A·g^-1）. Especially, the symmetric supercapacitor assembled on the basis of RuO2/rGONR electrode delivers high energy density （16.2 Wh·kg^-1） even at the power density of 9885 W·kg^-1, which is very essential for supercapacitors.
文摘The design of efficient Ru-based electrocatalysts with high intrinsic activities for acidic water oxidation is highly desirable and challenging for water splitting in proton exchange membrane electrolyzers.Here,for the first time,we engineer the charge density of Ru(IV)by creating tensile strains in the RuO2 shell of Ru@RuO2 core-shell nanoparticles,viz.Ru@RuO2-L.High-resolution spectroscopic characterizations confirm the presence of av.6%tensile strain in Ru-O bonds,which results in an effective reduction of the Ru(IV)charge density.The resultant Ru^X+(4<X<5)active sites greatly accelerate the oxygen evolution reaction(OER)in an acidic electrolyte,leading to a remarkably low overpotential of 191 mV at 10 mA cm^-2.These values are lower than those for the benchmark RuO2 catalyst and are also among the lowest for efficient Ru-based electrocatalysts reported thus far.The specific activity and mass activity are also greatly enhanced 4.2-fold and 17.7-fold compared to those of RuO2,respectively.The acidic OER activity improvement is ascribed to the lowered adsorption energy of*OOH,owing to the reduced charge density of Ru(IV),and the rapid charge transport owing to the Ru core.Ru@RuO2-L also demonstrates high feasibility as the anode catalyst for the overall water splitting in acidic media.
基金supported by the National Natural Science Foundation of China(No.22209035)the Major Science and Technology Projects of Yunnan Province(No.202302AH360001)the Natural Science Foundation of Hebei Province(No.E2020202091).
文摘RuO_(2) has been considered a potential alternative to commercial IrO_(2) for the oxygen evolution reaction(OER)due to its superior intrinsic activity.However,its inherent structure dissolution in acidic environments restricts its commercial applications.In this study,we report a novel Pd-doped ruthenium oxide(Pd–RuO_(2))nanosheet catalyst that exhibits improved activity and stability through a synergistic effect of Pd modulation of Ru electronic structure and the two-dimensional structure.The catalyst exhibits excellent performance,achieving an overpotential of only 204 mVat a current density of 10 mA cm^(-2).Impressively,after undergoing 8000 cycles of cyclic voltammetry testing,the overpotential merely decreased by 5 mV.The PEM electrolyzer with Pd0.08Ru0.92O_(2) as an anode catalyst survived an almost 130 h operation at 200 mA cm^(-2).To elucidate the underlying mechanisms responsible for the enhanced stability,we conducted an X-ray photoelectron spectroscopy(XPS)analysis,which reveals that the electron transfer from Pd to Ru effectively circumvents the over-oxidation of Ru,thus playing a crucial role in enhancing the catalyst's stability.Furthermore,density functional theory(DFT)calculations provide compelling evidence that the introduction of Pd into RuO_(2) effectively modulates electron correlations and facilitates the electron transfer from Pd to Ru,thereby preventing the overoxidation of Ru.Additionally,the application of the two-dimensional structure effectively inhibited the aggregation and growth of nanoparticles,further bolstering the structural integrity of the catalyst.
基金supported by the National R&D Program through the National Research Foundation of Korea(NRF)funded by Ministry of Science and ICT(2021K1A4A8A01079455)。
文摘Ammonia (NH_(3)) plays a key role in the agricultural fertilizer and commodity chemical industries and is useful for exploring hydrogen storage carriers.The electrochemical nitrogen reduction reaction (NRR) is receiving attention as an environmentally sustainable NH_(3) synthesis replacement for the traditional Haber–Bosch process owing to its near ambient reaction conditions (<100℃ and 1 atm).However,its NH_(3) yield and faradaic efficiency are extremely low because of the sluggish kinetics of N≡N bond dissociation and the hindrance from competitive hydrogen evolution.To overcome these challenges,we herein introduce a dual-functionalized ionic liquid (1-(4-hydroxybutyl)-3-methylimidazolium hydroxide[HOBIM]OH) for a highly dispersed ruthenium oxide electrocatalyst to achieve a biased NRR.The observed uniform distribution of RuO_(2) on the carbon fiber and increase in the surface area for N_(2) adsorption by limiting proton access can be attributed to the presence of imidazolium ions.Moreover,extensive N_(2) adsorption contributes to enhanced NRR selectivity with an NH_(3) yield of 3.0×10^(-10)mol cm^(-2)s^(-1)(91.8μg h^(-1)mg^(-1)) and a faradaic efficiency of 2.2%at-0.20 V_(RHE).We expect our observations to provide new insights into the design of effective electrode structures for electrochemical NH;synthesis.
基金National Natural Science Foundation of China(No.21978182)。
文摘Design of electrode materials for stable and efficient electrocatalytic oxidation of As(Ⅲ)in arsenic-contaminated groundwater poses a great challenge due to the rapid deactivation of catalysts resulting from the high oxygen evolution potential(OEP)and considerable barrier to generating reactive oxygen species(ROS).Herein,an innovative TNAs/SnO_(2)/PEDOT/Fe(Ⅲ)-RuO_(2) multilayer electrode was synthesized by utilizing a PEDOT-coated SnO_(2) interlayer as a supportive framework to combine Fe-doped amorphous RuO_(2) catalytic layer with TiO_(2) nanotube array substrate.Such electrode exhibited high activity and sta-bility for the oxidation of As(Ⅲ)to As(V)due to the large surface area provided by the TiO_(2) nanotube arrays and the SnO_(2)/PEDOT interlayer for facilitating the growth of the catalytic layer.The electrochem-ically active surface area of the electrode reached as high as 31.7 mF/cm^(2).Impressively,the doping of Fe into RuO_(2) layer led to a remarkable increase in the OEP value to 3.12 V,which boosted the indirect oxidation process mediated by ROS at a lower potential to achieve the As(Ⅲ)oxidation ratio of 98.5%.DFT calculations revealed that the Fe-doped amorphous RuO_(2) weakened the adsorption strength of·OH and.SO4-intermediates and lowered the energy barrier for generating ROS.Combined with ESR results,the formation of·OH and·SC4-with strong oxidizing properties was fully verified,providing further evi-dence for the involvement of ROS as the main mediator of the oxidation mechanism of As(Ⅲ).This work may provide valuable perspectives into the design of catalytic layer structures and heteroatom doping modifications for composite-coated electrodes.
基金the financial support by the National Natural Science Foundation of China(NSFC,21905288,and 51904288)the Zhejiang Provincial Natural Science Foundation(No.LZ21B030017)+2 种基金K.C.Wong Education Foundation(No.GJTD-2019-13)Ningbo Major Special Projects of the Plan“Science and Technology Innovation 2025”(Nos.2018B10056,and 2019B10046)Ningbo 3315 Program,and Natural Science Foundation of Fujian Province(No.2021J011150)。
文摘Organic semiconductors are promising candidates as photoactive layers for photoelectrodes used in photoelectrochemical(PEC)cells due to their excellent light absorption and efficient charge transport properties with the help of interfacial materials.However,the use of multilayers will make the charge transfer mechanism more complicated and decrease the PEC performance of the photoelectrode caused by the increased contact resistance.In this work,a PM6:Y6 bulk heterojunction(BHJ)-based photocathode is fabricated for efficient PEC hydrogen evolution reaction(HER)in an acidic aqueous solution.With RuO_(2)as an interfacial modification layer,the photocathode with a simple structure(fluorine-doped tin oxide(FTO)/PM6:Y6/RuO_(2))generates a maximum photocurrent density up to-15 m A/cm^(2)at 0 V vs.reference hydrogen electrode(RHE),outperforming all previously reported BHJ-based photocathodes in terms of PEC performance.The highest ratiometric power-saved efficiency of 3.7%is achieved at 0.4 V vs.RHE.
基金supported by Jinan Mingzhu Co., Ltd (HX20200364)。
文摘Hollow core-shell structure nanomaterials have been broadly used in energy storage, catalysis, reactor,and other fields due to their unique characteristics, including the synergy between different materials,a large specific surface area, small density, large charge carrying capacity and so on. However, their synthesis processes were mostly complicated, and few researches reported one-step encapsulation of different valence states of precious metals in carbon-based materials. Hence, a novel hollow core-shell nanostructure electrode material, RuO_(2)@Ru/HCs, with a lower mass of ruthenium to reduce costs was constructed by one-step hydrothermal method with hard template and co-assembled strategy, consisting of RuO_(2) core and ruthenium nanoparticles(Ru NPs) in carbon shell. The Ru NPs were uniformly assembled in the carbon layer, which not only improved the electronic conductivity but also provided more active centers to enhance the pseudocapacitance. The RuO_(2) core further enhanced the material’s energy storage capacity. Excellent capacitance storage(318.5 F·g^(-1)at 0.5 A·g^(-1)), rate performance(64.4%) from 0.5 A·g^(-1)to 20 A·g^(-1), and cycling stability(92.3% retention after 5000 cycles) were obtained by adjusting Ru loading to 0.92%(mass). It could be attributed to the wider pore size distribution in the micropores which increased the transfer of electrons and protons. The symmetrical supercapacitor device based on RuO_(2)@Ru/HCs could successfully light up the LED lamp. Therefore, our work verified that interfacial modification of RuO_(2) and carbon could bring attractive insights into energy density for nextgeneration supercapacitors.
文摘The acidic oxygen evolution reaction(OER)is central to water electrolysis using proton‐exchange membranes.However,even as benchmark catalysts in the acidic OER,Ru‐based catalysts still suffer from sluggish kinetics owing to the scaling relationship that arises from the traditional concerted proton‐electron transfer(CPET)process.Motivated by the knowledge that a charged surface may be favorable for accelerating the OER kinetics,we posited the incorporation of elements with pseudocapacitive properties into Ru‐based catalysts.Herein,we report a RuPbOx electrocatalyst for efficient and stable water oxidation in acid with a low overpotential of 191 mV to reach 10 mA cm^(−2) and a low Tafel slope of 39 mV dec^(−1).The combination of electrochemical analysis,X‐ray photoelectron spectroscopy,and in situ Raman spectroscopy demonstrated that the improved OER kinetics was associated with the formation of superoxide precursors on the strongly charged surface after Pb incorporation,indicating a non‐concerted proton‐electron transfer mechanism for the OER on RuPbOx.
文摘The ruthenium oxide(RuO_x) thin film was prepared by using the R.F.sputtering system.The RuO_x pH-sensitive electrode possesses a nearly-Nernstian pH sensitivity(about 57 mV/pH).For the enzyme penicillinase was immobilized directly onto a RuO_x pH-sensitive surface by 3-glycidoxypropyltrimethoxysilane(GPTS).Some characteristics of the biosensor, such as sensitivity,linear range,and drift,are investigated and the difference between penicillinase immobilized and without are compared.According to the time-constant model,we can extract the time constant and amplitude at the response curve of the drift.Subsequently,the extracted parameters were used to simulate the mechanism of the drift behavior.
基金Funded by National Natural Science Foundation of China (No.50872026and50602011)the Science Foundation of Heilongjiang Province (E200517)
文摘Hydrous ruthenium oxide,RuO2·xH2O,was synthesized through a sol-gel reaction of ruthenium chloride aqueous solution.The annealed RuO2·xH2O powders are aggregate of very small particles in nano-size of 70-80 nm and have abundant porous structure as observed by SEM.The effect of electrode thickness,PTFE binder and carbon black addition on the super-capacitive properties of thick RuO2·nH2O electrodes was investigated.At low scan rate of 5 mV/s,the specific capacitance of RuO2·xH2O (SCR,based on the weight of RuO2·xH2O only) for pure RuO2·xH2O and RuO2·xH2O-PTFE-CB electrodes can reach 665 F/g.Increasing electrode thickness and mixing PTFE into RuO2·xH2O lead to a degradation of SCR and rate capacity.By adding carbon black into RuO2·xH2O-PTFE mixture,the rate capacity of the thick electrode (RuO2·xH2O-PTFE-CB) can be improved close to the thick pure RuO2·xH2O electrode.However,mixing with PTFE and carbon black leads to a loss of the overall mass-specific capacitance.The reason for the dependence of SCR and rate capacity on electrode thickness,binder and carbon black addition was discussed based on the relation between the resistance and utilization rate of electrodes.
基金Project supported by the National Natural Science Foundation of China （Grant No 10274072）, and the Specialized Research Fund for the Doctoral Program of Higher Education of China （Grant No 20030335017）.
文摘This paper reports that the growth of RuO2（110） thin layer growth on Ru（0001） has been investigated by means of scanning tunnelling microscope （STM）. The STM images showed a domain structure with three rotational domains of RuO2（110） rotated by an angle of 120°. The as-grown RuO2（110） thin layer is expanded from the bulk-truncated RuO2（110） due to the large mismatch between RuO2（110） and the Ru（0001） substrate. The results also indicate that growth of RuO2（110） thin layer on the Ru（0001） substrate by oxidation tends first to formation of the Ru-O （oxygen） chains in the [001] direction of RuO2 （110）.
