7440-18-8Relevant articles and documents
REACTION OF Ru3(CO)12 WITH STYRENE
Johnson, Brian F. G.,Lewis, Jack,Aime, Silvio,Milone, Luciano,Osella, Domenico
, p. 247 - 252 (1982)
The reaction of styrene with Ru3(CO)12 yields the known complex Ru4(CO)12(PhC=CH) and the new cluster Ru4(CO)9(PhC=CH)(PhEt), in which a second molecule of styrene is hydrogenated and η6-bonded.
PHOTODEPOSITION OF Ru ON InP AND GaInPAs. CATALYTIC AND ELECTRONIC PROPERTIES.
Lewerenz,Michaelis
, p. 913 - 916 (1988)
The authors restrict this investigation to Ru/InP and Ru/GaInPAs contacts. The large grain polycrystalline quaternary semiconductor has been chosen because of differences in surface chemistry. Experimental data show that the typical current enhancement upon metallization is found. The increase in catalytic activity is larger for InP. A somewhat lower overall photoactivity is noted for GaInPAs.
Electrically benign Ru wet etching method for fabricating Ru/TiO 2 /Ru capacitor
Lee, Sang Young,Kim, Seong Keun,Kim, Kyung Min,Choi, Gyu-Jin,Han, Jeong Hwan,Hwang, Cheol Seong
, p. G47-G51 (2011)
Ru top electrode etching techniques for Ru/Ti O2 /Ru (RTR) thin film capacitor fabrication were examined. A dry etching process using a plasma mixture of O2, Cl2, and Ar gases deteriorated the leakage current properties significantly, which were not recovered by postannealing processes. The surface roughness was not a critical factor in determining the leakage characteristics. The etching damage along the etched edges was not the main cause of the leakage degradation but it was observed over the entire area, which was confirmed according to a comparison of capacitors with different perimeter/area ratios. For the wet etching of Ru films, the etch rates were evaluated using a periodic acid solution at various concentrations at 60°C. The Ru films etched using a 14 wt % periodic acid solution showed a moderate etch rate and a reasonable etching selectivity on the Ti O2 and Al2 O3 films. The as-wet-etched RTR capacitors showed a lower leakage current level than the dry-etched capacitors. Furthermore, the electrical properties of the wet-etched capacitor were improved significantly by a postannealing process.
Thermodynamic calculations and metallorganic chemical vapor deposition of ruthenium thin films using bis(ethyl-π-cyclopentadienyl)Ru for memory applications
Kang, Sang Yeol,Choi, Kook Hyun,Lee, Seok Kiu,Hwang, Cheol Seong,Kim, Hyeong Joon
, p. 1161 - 1167 (2000)
The equilibrium concentrations of the various gaseous and solid phases in metallorganic chemical vapor deposition of Ru thin films were calculated in the experimentally relevant temperature and oxygen partial pressure ranges. Although thermal decomposition of the precursor, bis(ethyl-π-cyclopentadienyl)Ru [Ru(EtCp)2] required a sufficient amount of oxygen, experimental results showed that up to a certain concentration of oxygen, Ru metal was deposited without any detectable RuO2 impurity. Thermodynamic calculations showed that all the supplied oxygen was consumed to oxidize carbon and hydrogen, cracked from the precursor ligand, rather than Ru. Thus, metal films could be obtained. There was an optimum oxygen-to-precursor ratio at which the pure Ru phase could be obtained with minimum generation of not only carbon and RuO2 but also detrimental hydrogen. Ru thin films with minimal carbon and RuO2 contamination could be obtained by optimization of the oxygen supply at a low deposition temperature at 300°C.
Sol-gel synthesis of hydrous ruthenium oxide nanonetworks from 1,2-epoxides
Walker, Jeremy,Bruce King,Tannenbaum, Rina
, p. 2290 - 2297 (2007)
Hydrous ruthenium oxide (RuO2·xH2O) xerogels were synthesized through the addition of a 1,2-epoxide, propylene oxide, to commercial hydrated ruthenium chloride, RuCl3·xH2O, in ethanol. After a blue-black monolithic gel formed in 4 h, the samples were allowed to age for 24 h and were dried in ambient conditions. The dried samples were then characterized by XPS, XRD, DTA and TGA. XPS showed the Ru(3d5/2) peak at a binding energy of 281.7 eV, corresponding to that of hydrous ruthenium oxide. XRD data revealed the synthesized material as amorphous. Heating the sample in inert atmospheres caused the complete reduction of the oxide to the zero-valent state, whereas heating the sample in air resulted in both crystalline anhydrous RuO2 and zero-valent ruthenium, depending on the method of heating. DTA traces showed an endotherm ending at 150 °C, corresponding to the loss of coordinated water, as well as two higher temperature crystallization exotherms when the sample was heated in both inert and oxygen-rich atmospheres. TGA runs also confirmed the complete reduction of the hydrous oxide when heated in nitrogen below 270 °C and the formation of anhydrous ruthenium oxide when heated in air, confirming the XRD results.
PEALD of a ruthenium adhesion layer for copper interconnects
Kwon, Oh-Kyum,Kwon, Se-Hun,Park, Hyoung-Sang,Kang, Sang-Won
, p. C753-C756 (2004)
Ruthenium thin films were produced by plasma-enhanced atomic layer deposition (PEALD) using an alternating supply of bis(ethylcyclopentadienyl)ruthenium [Ru(EtCp)2] and NH3 plasma at a deposition temperature of 270°C. The film thickness per cycle was self-limited at 0.038 nm/cycle, which was thinner than the thickness obtained from the conventional ALD using oxygen instead of NH3 plasma. The ruthenium thin film prepared with PEALD had a preferential orientation toward (002), and it was progressively promoted with NH3 plasma power. The PEALD of ruthenium shows a merit in controlling ultrathin film thickness with less than 2 nm more precisely and more easily than the conventional ALD, due to the reduced transient period at the initial film growth stage. Also, ruthenium thin film improved the interfacial adhesion of metallorganic chemical vapor deposited copper to diffusion barrier metals by forming Cu-Ru chemical bonds at the interface without degrading the film resistivity of copper.
CHEMICAL VAPOR DEPOSITION OF RUTHENIUM AND RUTHENIUM DIOXIDE FILMS.
Green,Gross,Papa,Schnoes,Brasen
, p. 2677 - 2685 (1985)
The preparation of Ru and RuO//2 thin films by organometallic chemical vapor deposition and an investigation of the films' properties are reported. Ru is of interest for metallization in integrated circuit fabrication because its thermodynamically stable oxide, RuO//2, also exhibits metallic conductivity. As a result, oxidation during processing of Ru is a less critical concern than in current metallization technology. Taking advantage of the benefits of chemical vapor deposition, such as conformal coverage and low temperature, damage-free deposition, we have deposited Ru, RuO//2, and Ru/RuO//2 by pyrolysis of three organoruthenium complexes. Films of a given phase composition were deposited under a wide variety of conditions and exhibited large variations in electrical resistivity and carbon content.
Regulative Electronic States around Ruthenium/Ruthenium Disulphide Heterointerfaces for Efficient Water Splitting in Acidic Media
Chen, Ding,Gong, Lei,Guo, Yao,Liu, Fang,Luo, Jiahuan,Mu, Shichun,Shi, Wenjie,Wang, Pengyan,Wu, Jinsong,Xu, Hanwen,Yang, Yue,Zhang, Chengtian,Zhu, Jiawei
, p. 12328 - 12334 (2021)
Theoretical calculations unveil the charge redistribution over abundant interfaces and the enhanced electronic states of Ru/RuS2 heterostructure. The resulting surface electron-deficient Ru sites display optimized adsorption behavior toward diverse reaction intermediates, thereby reducing the thermodynamic energy barriers. Experimentally, for the first time the laminar Ru/RuS2 heterostructure is rationally engineered by virtue of the synchronous reduction and sulfurization under eutectic salt system. Impressively, it exhibits extremely high catalytic activity for both OER (201 mV @ 10 mA cm?2) and HER (45 mV @ 10 mA cm?2) in acidic media due to favorable kinetics and excellent specific activity, consequently leading to a terrific performance in acidic overall water splitting devices (1.501 V @ 10 mA cm?2). The in-depth insight into the internal activity origin of interfacial effect could offer precise guidance for the rational establishment of hybrid interfaces.
Pantani, F.
, p. 116 - 132 (1962)
On the nature of the active state of supported ruthenium catalysts used for the oxidation of carbon monoxide: Steady-state and transient kinetics combined with in situ infrared spectroscopy
Assmann, Jens,Narkhede, Vijay,Khodeir, Lamma,Loì?ffler, Elke,Hinrichsen, Olaf,Birkner, Alexander,Over, Herbert,Muhler, Martin
, p. 14634 - 14642 (2004)
The oxidation of CO over Ru/MgO and Ru/SiO2 catalysts was used as a simple model reaction to derive turnover frequencies at atmospheric pressure, which were observed to agree with kinetic data obtained under high-vacuum conditions with supported ruthenium catalysts and the RuO 2(110) single-crystal surface. Thus, it was possible to bridge both the pressure and the materials gap. However, a partial deactivation was observed initially, which was identified as an activated process, both under net reducing and net oxidizing conditions. Temperature-programmed reduction (TPR) experiments were performed subsequently in the same reactor, to monitor the degree of oxidation, as a function of the reaction temperature and the CO/O 2 reactant feed ratio. Using in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) measurements, the structural changes of the ruthenium catalysts during the oxidation of CO were confirmed, under relevant reaction conditions. Under net reducing conditions, only domains of RuO2 seem to exist on the metallic ruthenium particles, whereas, under net oxidizing conditions, the ruthenium particles were fully oxidized to bulk RuO2 particles, which may expose less-active facets, such as the RuO2(100)-c(2 ?? 2) surface.
Spectroscopic and thermal studies of chromium(III), molybdenum(VI) and ruthenium(0) complexes of maleic hydrazide
Mohamed, Hassan A.,Ali, Saadia A.,Ramadan, Ramadan M.
, (2006)
Interaction of maleic hydrazide (LH2) with [Cr(CO)6] in air at atmospheric pressure resulted in the formation of the complex [(LH)Cr(μ-O)2Cr(LH)] (1). Reaction of LH2 with [Mo(CO)6] in air also gave t
Thermal decomposition kinetics of some metal complexes of N,N-diethyl-N'-benzoylthiourea
Oezpozan,Arslan,Oezpozan,Merdivan,Kuelcue
, p. 955 - 965 (2000)
Thcrmogravimctry (TG) and differential thermal analysis (DTA) were performed on the complexes with general formula (M(DEBT)n (where M=Fe, Co, Ni, Cu or Ru; n=2, or 3 and DEBT=N,N-di-cthyl-N'-bcnzoylthiourea). Derivative thermogravimctric (DTG) curves were also recorded in order to obtain decomposition data on the complexes. The complexes of Fe(III), Co(II), Ni(II), Cu(ll) and Ru(III) displayed two- or three-stage decomposition patterns when heated in a dynamic nitrogen atmosphere. Mass loss considerations relating to the decomposition stages indicated the conversion of the complexes to the sulfidcs or to the corresponding metal alone (Cu, Ru, NiS, CoS or FeS). Mathematical analysis of the TG and DTG data showed that the order of reaction varied between 0.395 and 0.973. Kinetic parameters such as the decomposition energy, the entropy of activation and the pre-exponcntial factor are reported.
Electrochemical characterization of platinum-ruthenium nanoparticles prepared by water-in-oil microemulsion
Solla-Gullón,Vidal-Iglesias,Montiel,Aldaz
, p. 5079 - 5088 (2004)
The synthesis, physical characterization, decontamination and some electrocatalytic properties of PtRu nanoparticles prepared using the microemulsion method are reported. The nanoparticles are synthesized by reduction with sodium borohydride of H2PtCl6 and RuCl 3 in a water-in-oil microemulsion of water/polyethylenglycol- dodecylether (BRIJ 30)/n-heptane. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and energy dispersive analysis by X-rays (EDAX) experiments were carried out to characterize the single and bimetallic nanoparticles obtained. Cyclic voltammograms (CV) of clean nanoparticles were obtained after a controlled decontamination procedure of their surfaces. CO adsorption-oxidation and methanol electrooxidation were used as test reactions to check the electrocatalytic behaviour of the bimetallic nanoparticles. Pt 80Ru20 (nominal atomic composition) nanoparticles are the best electrocatalyst for both COad and methanol oxidation. All these results show that the microemulsion method can be used to produce bimetallic nanoparticles in a very easy way. The method can be very easily scaled-up for industrial use.
Thermodynamic stability of CaRuO3
Mallika, C.,Sreedharan, O. M.
, p. 273 - 278 (1991)
The e.m.f. of the galvanic cell Pt, CaO, CaRuO3, Ru|15 CSZ|O2 (PO(2) = 0.21 atm), Pt was studied over the range 971-1312 K using 15wt.%CaO-stabilized ZrO2 (15 CSZ) as the solid electrolyte. This study yielded th
Ruthenium Bottom Electrode Prepared by Electroplating for a High Density DRAM Capacitor
Kwon, Oh Joong,Cha, Seung Hwan,Kim, Jae Jeong
, p. C127-C132 (2004)
The possibility of Ru electroplating for application as the bottom electrode in high density dynamic random access memory (DRAM) capacitors was investigated. Prior to Ru electroplating on a TiN substrate, HF cleaning and Pd activation were performed. Removal of Ti oxide from the TiN substrate by HF treatment enabled Pd activation, which enhanced the nucleation of Ru on TiN substrate. Optimized pretreatments led to a continuous Ru film deposition. The surface roughness was measured to be 4.4 nm at 45 nm Ru film on the bare substrate. Moreover Ru electroplating method was also applied to a capacitor node-type TiN wafer. The deposition rate of Ru on the patterned wafer was the same as that on a bare wafer. The film showed 93% step coverage and good adhesion, comparable to CVD Ru films.
Atomic Layer Deposition of Ruthenium Thin Films for Copper Glue Layer
Kwon, Oh-Kyum,Kim, Jae-Hoon,Park, Hyoung-Sang,Kang, Sang-Won
, p. G109-G112 (2004)
Ruthenium thin films were produced by atomic layer deposition (ALD) using an alternating supply of bis(ethylcyclopentadienyl)ruthenium [Ru(EtCp) 2] and oxygen at a deposition temperature of 270°C. The relative ratio of the Ru(EtCp)2 adsorbed on the film surface to the oxygen partial pressure in the following oxygen pulse determines whether Ru or RuO 2 film was obtained. At the range with higher relative ratio the film was composed of ruthenium, but the film deposited at the lower range was revealed to be ruthenium oxide. In case of the ruthenium thin film, the film thickness per cycle was saturated at 0.15 nm/cycle, and its resistivity was about 15 μω cm. The impurities of carbon and oxygen were incorporated into the film with less than 2 atom %. It was also demonstrated that the ruthenium thin films prepared by ALD can be used as an excellent glue layer to improve the interfacial adhesion of metallorganic chemical vapor deposited copper to TiN. Secondary ion mass spectroscopy analysis showed that the ruthenium glue layer suppressed the interfacial contaminants, such as carbon and fluorine, which originated from the metallorganic precursors of copper.
Electrochemical preparation of photosensitive porous n-type Si electrodes, modified with Pt and Ru nanoparticles
Macherzynski,Milczarek,Mamykin,Romanyuk,Kasuya
, p. 4395 - 4401 (2010)
A novel electrochemical procedure for preparation of the very stable, thin modifying layer onto the n-type Si surface was elaborated. The modification consisted of platinum or/and ruthenium ultrafine particles etched into the porous Si film. A unique sequence of modifications was applied: at first the metal particles were evenly electrodeposited onto a flat silicon surface, and in the next electrochemical step the porous structure was produced. The platinum coverage and mean particle diameter were well controlled by the electrochemical programs. All the attempts and progress in modifications were monitored by scanning electron microscope (SEM) observations. Furthermore, the materials obtained were compared with the non-porous, Pt or/and Ru modified electrodes by testing them as anodes in the photoelectrochemical (PEC) cell with organic Br2/2Br- solution. In general, the porous photo-anodes gave higher output powers and the light-to-electricity conversion efficiencies. The best performance was observed for the PEC cell employing the porous anode with sequentially electrodeposited Ru and Pt particles, respectively (PS-Si/Ru/Pt).11 PS-Si means the porous silicon film; Si/Pt/Ru describes the sequence of metal depositions onto Si, in this case the Pt deposition is followed by the Ru deposition. This cell maintained good electrical parameter values during the 2-week tests, having a maximum output power equal to 0.23 mW/cm2 and a cell conversion efficiency of 8.5%. The PS-Si/Pt photo-anode gained 0.21 mW/cm2 and 7.8%, respectively.
Calcium ruthenates: Determination of Gibbs energies of formation using electrochemical cells
Jacob, K. Thomas,Lwin, Kay Thi,Waseda, Yoshio
, p. E227-E232 (2003)
Metallic Ru has been found to coexist separately with CaO, RuO2, and the interoxide phases, Ca2RuO4, Ca3Ru2O7, and CaRuO3, present along the pseudobinary system CaO-RuO2. The standard Gibbs energies of formation (Δf(ox)G°) of the three calcium ruthenates from their component oxides have been measured in the temperature range 925-1350 K using solid-state cells with yttria-stabilized zirconia as the electrolyte and Ru + RuO2 as the reference electrode. The standard Gibbs energies of formation (Δf(ox)G°) of the compounds can be represented by Ca2RuO4: Δf(ox)G°/J mol-1 = -38,340 - 6.611 T (±120), Ca3Ru2O7: Δf(ox)G°/J mol-1 = 75,910 - 11.26 T (±180), and CaRuO3: Δf(ox)G°/J mol-1 = -35,480-3,844 T (±70). The data for Ca2RuO4 corresponds to the stoichiometric composition, which has an orthorhombic structure, space group Pbca, with short c axis ( S form). The structural features of the ternary oxides responsible for their mild entropy stabilization are discussed. A three-dimensional oxygen potential diagram for the system Ca-Ru-O is developed as a function of composition and temperature from the results obtained. Using the Neumann-Kopp rule to estimate the heat capacity of the ternary oxides relative to their constituent binary oxides, the standard enthalpies of formation of the three calcium ruthenates from the elements and their standard entropies at 298.15 K are evaluated.
Structure and reactivity of Ru nanoparticles supported on modified graphite surfaces: A study of the model catalysts for ammonia synthesis
Song, Zhen,Cai, Tanhong,Hanson, Jonathan C.,Rodriguez, Jose A.,Hrbek, Jan
, p. 8576 - 8584 (2004)
Supported ruthenium metal catalysts have higher activity than traditional iron-based catalysts used industrially for ammonia synthesis. A study of a model Ru/C catalyst was carried out to advance the understanding of structure and reactivity correlations in this structure-sensitive reaction where dinitrogen dissociation is the rate-limiting step. Ru particles were grown by chemical vapor deposition (CVD) via a Ru3(CO)12 precursor on a highly oriented pyrolytic graphite (HOPG) surface modified with one-atomic-layer-deep holes mimicking activated carbon support. Scanning tunneling microscopy (STM) has been used to investigate the growth, structure, and morphology of the Ru particles. Thermal desorption of dissociatively adsorbed nitrogen has been used to evaluate the reactivity of the Ru/HOPG model catalysts. Two different Ru particle structures with different reactivities to N2 dissociation have been identified. The initial sticking coefficient for N2 dissociative adsorption on the Ru/HOPG model catalysts is ～10-6, 4 orders larger compared to that of Ru single-crystal surfaces.
Thermal stability of RuSr2GdCu2O8, Ru 1 - xSr2GdCu2O8 - y, RuO2
Matveev,Maljuk,Kulakov,Lin,Habermeier
, p. 139 - 146 (2004)
Thermal stability of RuSr2GdCu2O8, Ru 0.9Sr2GdCu2O8-y, and RuO2 powders in oxygen has been studied by thermogravimetry. Decomposition of RuSr2GdCu2O8 and Ru0.9Sr 2GdCu2O8-y samples in 0.85 bar of oxygen appears as a solid phase process at ～1050 °C. This is followed by peritectic decomposition with onset starting at ～1110 °C for the stoichiometric sample and at ～1090 °C for the Ru deficient one. We observed that sublimation of ruthenium oxide in 0.85 bar of oxygen starts at ～850 °C and sample's humidity significantly increases a sublimation rate. Enhanced sublimation above 1060 °C was observed for powder mixtures (RuO2+xCuO), x=0.1, 0.2, 0.5. Analysis of the sublimation process of these mixtures suggests existence of an unknown compound in Ru-Cu-O system with approximate composition Ru1-xCuxO2-y, xa synthetic route of rutenates and, in particular RuSr 2GdCu2O8 phase, eliminating Ru off-stoichiometry and phase separation, are discussed.
In situ Ru K-edge EXAFS of CO adsorption on a Ru modified Pt/C fuel cell catalyst
Rose, Abigail,Bilsborrow, Robert,King, Colin R.,Ravikumar,Qian, Yangdong,Wiltshire, Richard J.K.,Crabb, Eleanor M.,Russell, Andrea E.
, p. 5262 - 5266 (2009)
The Ru-CO bond of CO adsorbed on a Ru modified Pt/C fuel cell catalyst has been directly probed by in situ EXAFS at the Ru K-edge, providing evidence of a CO:metal surface atom ratio greater than 1:1 and that CO is adsorbed at bridging sites associated wi
Anodically formed oxide films and oxygen reduction on electrodeposited ruthenium in acid solution
Metiko?-Hukovi?,Babi?,Jovi?,Gruba?
, p. 1157 - 1164 (2006)
The impedance of the anodically formed hydrous Ru oxide in the system Ru|oxide film|1 M HClO4 solution has been studied in the range of potentials where the electrode process occurs by a double electron and proton exchange between the oxide film and the solution. The results allowed us to clearly distinguish between the surface process at higher frequency and the bulk process at lower frequency. The high-frequency charging is found to be coupled to Faradaic charging at the film/solution interface. Evaluation of the impedance data at lower frequency, using diffusion equations for the finite boundary conditions, yields an effective proton diffusion coefficient to be 10 -10 to 10-11 cm2 s-1. Oxygen reduction on the spontaneously oxidized ruthenium electrode was discussed on the basis of a rotating ring-disk voltammetry.
Don, J. A.,Pijpers, A. P.,Scholten, J. J. F.
, p. 296 - 306 (1983)
Direct regeneration of NADH on a ruthenium modified glassy carbon electrode
Azem, Amir,Man, Felise,Omanovic, Sasha
, p. 283 - 299 (2004)
The regeneration of NADH in a batch electrochemical reactor using a ruthenium modified glassy carbon electrode (RuGC) has been investigated. The information on the structure of the electrode/electrolyte interface in the presence of NAD+ in the solution, the kinetics of NAD+ reduction, and the batch-electrolysis NADH regeneration has been obtained using electrochemical techniques of dc linear potential (LP) and constant potential (CA) polarization, ac differential capacitance (DC), and electrochemical impedance spectroscopy (EIS). It has been shown that the modification of GC by a sub-monolayer of Ru can provide an electrode surface capable of reducing NAD+ directly to NADH at a high yield of enzymatically active 1,4-NADH (96%). From the electrochemical point of view, the reaction is irreversible and occurs at high cathodic overpotentials, where the reaction rate is controlled by the surface diffusion of electroactive species. EIS measurements have shown that the electrode/electrolyte interface and the corresponding charge- and mass-transfer processes can be described by an electrical equivalent circuit composed of two time constants in parallel, with the additional contribution of a mass-transport Warburg impedance element. The time constant recorded at higher frequencies represents the response of a GC part of the electrode surface, while the lower-frequency time constant can be related to the response of Ru sites on the electrode surface. It has been determined that the NAD+ reduction reaction is of first order with respect to NAD+. The calculated apparent heterogeneous reaction rate constant values are rather low, which is due to the slow mass-transport of electroactive species at the electrode surface. The kinetic analysis has demonstrated that a very good agreement between the apparent heterogeneous reaction rate constant values calculated using three different experimental techniques is obtained.
Formation of Ru nanocrystals by plasma enhanced atomic layer deposition for nonvolatile memory applications
Yim, Sung-Soo,Lee, Moon-Sang,Kim, Ki-Su,Kim, Ki-Bum
, (2006)
The formation of Ru nanocrystals is demonstrated on a SiO2 substrate by plasma enhanced atomic layer deposition using diethylcyclopentadienyl ruthenium and NH3 plasma. The island growth of Ru was observed at the initial stages of the film formation up to a nominal thickness of 11.1 nm. A maximum Ru nanocrystal spatial density of 9.7 × 1011 /cm2 was achieved with an average size of 3.5 nm and standard deviation of the size of 20%. Electron charging/discharging effect in the Ru nanocrystals is demonstrated by measuring the flatband voltage shift in the capacitance-voltage measurement of metal-oxide-semiconductor memory capacitor structure.
Highly dispersed ultra-fine Ru nanoparticles anchored on nitrogen-doped carbon sheets for efficient hydrogen evolution reaction with a low overpotential
Gao, Menghan,Wang, Zhihong,Sun, Shichao,Jiang, Deli,Wei, Wenxian,Chen, Min
, (2020/12/21)
Development of highly efficient and costeffective hydrogen evolution reaction (HER) electrocatalyst that rivals benchmark Pt is highly desirable but challengeable. In this work, the integration of uniformly dispersed ultra-fine Ru nanoparticles with the nitrogen-doped carbon sheets (NCs) is reported as an efficient electrocatalyst. The Ru/NCs composite catalyst possesses abundant catalytic activity sites, and the synergy effect between Ru and NCs can modulate the electronic structure and adsorption of reaction intermediate to enhance the HER activity. Remarkably, the optimal 20% Ru/NCs catalyst delivers an overpotential of as low as 13 mV at the current density of 10 mA cm?2 and with a Tafel slope of 31.8 mV dec?1, which is superior to most of recently reported Ru-based electrocatalysts and even, superior to the state of the art Pt/C catalyst. This work provides an effective strategy for the development of ultra-efficient electrocatalyst for the water splitting in alkaline condition.
Enhancing electrochemical nitrogen reduction with Ru nanowires: via the atomic decoration of Pt
An, Changhua,Chen, Peng,Yang, Liting,Zhang, Jichao,Zhang, Weiqing,Zhu, Junfa
supporting information, p. 25142 - 25147 (2020/12/25)
Achieving an efficient electrochemical nitrogen reduction reaction (ENRR) remains a great challenge, demanding the development of a new strategy for ENRR catalyst engineering. Herein, we demonstrate a largely improved ENRR by the controlled engineering of Ru nanowires with atomic Pt decoration. Specifically, the readily synthesized Ru88Pt12 nanowires exhibit a high NH3 production rate of 47.1 μg h-1 mgcat-1 and faradaic efficiency of 8.9% at -0.2 V, which are 5.3 and 14.6 times higher than those values for Ru nanowires. They also show outstanding stability, as evidenced by the full preservation of the NH3 yield and faradaic efficiency even after 15 h of electrocatalysis. As revealed by theoretical investigations, the d-band center of Ru atoms is upshifted by the tensile strain due to the presence of Pt atoms, leading to the selective enhancement of N2 adsorption and the stabilization of N2H?. Such an atomic engineering method may be applied to precisely tailor other metal nanocatalysts for different applications.
