共查询到20条相似文献,搜索用时 46 毫秒
1.
Fe K‐Edge X‐ray Absorption Fine Structure Determination of γ‐Al2O3‐Supported Iron‐Oxide Species
下载免费PDF全文
![点击此处可从《Chemphyschem》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Atsuko Tomita Dr. Takeshi Miki Takeru Tango Tatsuro Murakami Hideyuki Nakagawa Dr. Yutaka Tai 《Chemphyschem》2015,16(9):2015-2020
The structure of FeOx species supported on γ‐Al2O3 was investigated by using Fe K‐edge X‐ray absorption fine structure (XAFS) and X‐ray diffraction (XRD) measurements. The samples were prepared through the impregnation of iron nitrate on Al2O3 and co‐gelation of aluminum and iron sulfates. The dependence of the XRD patterns on Fe loading revealed the formation of α‐Fe2O3 particles at an Fe loading of above 10 wt %, whereas the formation of iron‐oxide crystals was not observed at Fe loadings of less than 9.0 wt %. The Fe K‐edge XAFS was characterized by a clear pre‐edge peak, which indicated that the Fe?O coordination structure deviates from central symmetry and that the degree of Fe?O?Fe bond formation is significantly lower than that in bulk samples at low Fe loading (<9.0 wt %). Fe K‐edge extended XAFS oscillations of the samples with low Fe loadings were explained by assuming an isolated iron‐oxide monomer on the γ‐Al2O3 surface. 相似文献
2.
Facile Synthesis of Three‐Dimensional Pt‐TiO2 Nano‐networks: A Highly Active Catalyst for the Hydrolytic Dehydrogenation of Ammonia–Borane
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Mohammad Aref Khalily Hamit Eren Serdar Akbayrak Hepi Hari Susapto Prof. Necmi Biyikli Prof. Saim Özkar Prof. Mustafa O. Guler 《Angewandte Chemie (International ed. in English)》2016,55(40):12257-12261
Three‐dimensional (3D) porous metal and metal oxide nanostructures have received considerable interest because organization of inorganic materials into 3D nanomaterials holds extraordinary properties such as low density, high porosity, and high surface area. Supramolecular self‐assembled peptide nanostructures were exploited as an organic template for catalytic 3D Pt‐TiO2 nano‐network fabrication. A 3D peptide nanofiber aerogel was conformally coated with TiO2 by atomic layer deposition (ALD) with angstrom‐level thickness precision. The 3D peptide‐TiO2 nano‐network was further decorated with highly monodisperse Pt nanoparticles by using ozone‐assisted ALD. The 3D TiO2 nano‐network decorated with Pt nanoparticles shows superior catalytic activity in hydrolysis of ammonia–borane, generating three equivalents of H2. 相似文献
3.
Metal Oxide‐Coated Three‐Dimensional Graphene Prepared by the Use of Metal–Organic Frameworks as Precursors
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Xianhong Rui Wenhui Shi Prof. Qingyu Yan Prof. Hua Zhang 《Angewandte Chemie (International ed. in English)》2014,53(5):1404-1409
A simple method for the preparation of metal‐oxide‐coated three‐dimensional (3D) graphene composites was developed. The metal–organic frameworks (MOFs) that served as the precursors of the metal oxides were first synthesized on the 3D graphene networks (3DGNs). The desired metal oxide/3DGN composites were then obtained by a two‐step annealing process. As a proof‐of‐concept application, the obtained ZnO/3DGN and Fe2O3/3DGN materials were used in a photocatalytic reaction and a lithium‐ion battery, respectively. We believe this method could be extended to the synthesis of other metal oxide/3DGN composites with 3D structures simply through the appropriate choice of specific MOFs as precursors. 相似文献
4.
Atomic Layer Deposition of Hafnium(IV) Oxide on Graphene Oxide: Probing Interfacial Chemistry and Nucleation by using X‐ray Absorption and Photoelectron Spectroscopies
下载免费PDF全文
![点击此处可从《Chemphyschem》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Theodore E. G. Alivio Luis R. De Jesus Dr. Robert V. Dennis Ye Jia Dr. Cherno Jaye Dr. Daniel A. Fischer Prof. Uttam Singisetti Prof. Sarbajit Banerjee 《Chemphyschem》2015,16(13):2842-2848
Interfacing graphene with metal oxides is of considerable technological importance for modulating carrier density through electrostatic gating as well as for the design of earth‐abundant electrocatalysts. Herein, we probe the early stages of the atomic layer deposition (ALD) of HfO2 on graphene oxide using a combination of C and O K‐edge near‐edge X‐ray absorption fine structure spectroscopies and X‐ray photoelectron spectroscopy. Dosing with water is observed to promote defunctionalization of graphene oxide as a result of the reaction between water and hydroxyl/epoxide species, which yields carbonyl groups that further react with migratory epoxide species to release CO2. The carboxylates formed by the reaction of carbonyl and epoxide species facilitate binding of Hf precursors to graphene oxide surfaces. The ALD process is accompanied by recovery of the π‐conjugated framework of graphene. The delineation of binding modes provides a means to rationally assemble 2D heterostructures. 相似文献
5.
Shigeo Sato Koji Omori Sawa Araki Yohei Takahashi Kazuaki Wagatsuma 《Surface and interface analysis : SIA》2009,41(6):496-501
Nitriding phenomena that occur on the surfaces of pure Fe and Fe? Cr alloy (16 wt% Cr) samples were investigated. An Ar + N2 mixture‐gas glow‐discharge plasma was used so that surface nitriding could occur on a clean surface etched by Ar+ ion sputtering. In addition, the metal substrates were kept at a low temperature to suppress the diffusion of nitrogen. These plasma‐nitriding conditions enabled us to characterize the surface reaction between nitrogen radicals and the metal substrates. The emission characteristics of the band heads of the nitrogen molecule ion (N2+) and nitrogen molecule from the glow‐discharge plasma suggest that the active nitrogen molecule is probably the major nitriding reactant. AES and angle‐resolved XPS were used to characterize the thickness of the nitride layer and the concentration of elements and chemical species in the nitride layer. The thickness of the nitride layer did not depend on the metal substrate type. An oxide layer with a thickness of a few nanometers was formed on the top of the nitride layer during the nitriding process. The oxide layer consisted of several species of Nx‐Fey‐O, NO+, and NO2?. In the Fe? Cr alloy sample, these oxide species could be reduced because chromium is preferentially nitrided. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
6.
Bin Dong Prof. Yingzhou Huang Dr. Naisen Yu Dr. Yurui Fang Dr. Baosheng Cao Dr. Yuanzuo Li Dr. Hongxing Xu Prof. Mengtao Sun Prof. 《化学:亚洲杂志》2010,5(8):1824-1829
The one‐dimensional (1D) transition‐metal oxide MoO3 belt is synthesized and characterized with X‐ray diffraction, scanning electron microscopy, and Raman spectroscopy. Charge‐transfer‐(CT) enhanced Raman scattering of 4‐mercaptobenzoic acid (4‐MBA) on a 1D MoO3 belt was investigated experimentally and theoretically. The chemical enhancement of surface‐enhanced Raman scattering (SERS) of 4‐MBA on the MoO3 belt by CT is in the order of 103. The SERS of 4‐MBA was investigated theoretically by using a quantum chemical method. The remote SERS of 4‐MBA along the 1D MoO3 belt (the light excitation to one side of the MoO3 belt, and the SERS spectrum is collected on the other side of the MoO3 belt) is also shown experimentally, which provides potential applications of SERS. The incident polarization dependence of remote SERS spectra has also been investigated experimentally. 相似文献
7.
An O3‐type Oxide with Low Sodium Content as the Phase‐Transition‐Free Anode for Sodium‐Ion Batteries
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Chenglong Zhao Dr. Maxim Avdeev Prof. Liquan Chen Prof. Yong‐Sheng Hu 《Angewandte Chemie (International ed. in English)》2018,57(24):7056-7060
Layered transition metal oxides NaxMO2 (M=transition metal) with P2 or O3 structure have attracted attention in sodium‐ion batteries (NIBs). A universal law is found to distinguish structural competition between P2 and O3 types based on the ratio of interlayer distances of the alkali metal layer d(O‐Na‐O) and transition‐metal layer d(O‐M‐O). The ratio of about 1.62 can be used as an indicator. O3‐type Na0.66Mg0.34Ti0.66O2 oxide is prepared as a stable anode for NIBs, in which the low Na‐content (ca. 0.66) usually undergoes a P2‐type structure with respect to NaxMO2. This material delivers an available capacity of about 98 mAh g?1 within a voltage range of 0.4–2.0 V and exhibits a better cycling stability (ca. 94.2 % of capacity retention after 128 cycles). In situ X‐ray diffraction reveals a single‐phase reaction in the discharge–charge process, which is different from the common phase transitions reported in O3‐type electrodes, ensuring long‐term cycling stability. 相似文献
8.
Aimei Gao Dr. Xinrui Miao Dr. Jie Liu Dr. Ping Zhao Dr. Jinwang Huang Dr. Wenli Deng Prof. Dr. 《Chemphyschem》2010,11(9):1951-1955
The synthesis and self‐assembly behavior of porphyrin–polypyridyl ruthenium(II) hybrid, which consists of a flexible alkyl chain attached with two conjugated moieties is described. The electronic absorption spectrum and emission spectra show that the [C8‐TPP‐(ip)Ru(phen)2](ClO4)2, abbreviated as (C8ip)TPPC has optical properties. Scanning tunneling microscopy (STM) studies found that the π–π interaction and metal–ligand interaction allow (C8ip)TPPC to form self‐assembled structure and have an edge‐on orientation on the highly oriented pyrolytic graphite (HOPG) surface. The multidentate structure in (C8ip)TPPC molecules act as linkers between the molecules and form metal–ligand coordination, which forces the assembly process in the direction of stable columnar arrays. In addition, although the sample was stored for two months in ambient conditions, STM experiments showed that the order of (C8ip)TPPC self‐assembly only slightly decreased which indicates that the self‐assembled monolayer is stable. This work demonstrates that introducing a metal‐ligand in the porphyrin‐polypyridyl compound is a useful strategy to obtain novel surface assemblies. 相似文献
9.
Nerea Ruiz del Árbol Irene Palacio Gonzalo Otero‐Irurueta José I. Martínez Pedro L. de Andrés Oleksander Stetsovych María Moro‐Lagares Pingo Mutombo Martin Svec Pavel Jelínek Albano Cossaro Luca Floreano Gary J. Ellis María F. López Prof. José A. Martín‐Gago 《Angewandte Chemie (International ed. in English)》2018,57(28):8582-8586
On‐surface synthesis is an emerging approach to obtain, in a single step, precisely defined chemical species that cannot be obtained by other synthetic routes. The control of the electronic structure of organic/metal interfaces is crucial for defining the performance of many optoelectronic devices. A facile on‐surface chemistry route has now been used to synthesize the strong electron‐acceptor organic molecule quinoneazine directly on a Cu(110) surface, via thermally activated covalent coupling of para‐aminophenol precursors. The mechanism is described using a combination of in situ surface characterization techniques and theoretical methods. Owing to a strong surface‐molecule interaction, the quinoneazine molecule accommodates 1.2 electrons at its carbonyl ends, inducing an intramolecular charge redistribution and leading to partial conjugation of the rings, conferring azo‐character at the nitrogen sites. 相似文献
10.
《Chemphyschem》2004,5(2):202-208
We have designed and synthesized a series of Schiff base derivatives, and studied their structural features in two‐dimensional (2D) and three‐dimensional (3D) states by combining scanning tunneling microscopy (STM) and X‐ray diffraction experiments. The Schiff‐base derivatives with short alkyl chains crystallize easily, which allows a detailed structural analysis by X‐ray diffraction. Due to the strong adsorbate–substrate interactions, those bases with long alkyl chains easily form 2D assemblies on highly oriented pyrolytic graphite (HOPG). The STM images indicate also that the introduction of two methoxy groups into the molecule can change the structure of these 2D assemblies as a result of the increased steric hindrances, for example: the Schiff‐base derivative, bearing both methoxy groups and C16H33 tails, forms 2D Moiré patterns, and an alignment of pairing Schiff‐base molecules may be easily resolved. Conversely, the Schiff base derivative, bearing solely C16H33 tails, forms 2D non‐Moiré patterns. It is demonstrated that the 3D structural features result from the compromise of intermolecular interactions of different molecular moieties. However, there is one more factor, which also governs the 2D structure: the adsorbate‐substrate interaction. The 3D crystal structure may thus help to understand many factors involved in the formation of 2D structures, and would be helpful for designing new molecular assemblies with tailoring functions. 相似文献
11.
《Electroanalysis》2018,30(1):84-93
Electrocatalytic reduction of CO2 to formate on carbon based electrodes is known to suffer from low electrochemical reaction activity and product selectivity. Pd/three‐dimensional graphene (Pd/3D‐RGO), In/3D‐RGO and Pd‐In/3D‐RGO for the electrochemical reduction of CO2 were prepared by a mild method that combines chemical and hydrothermal. The metal/3D‐graphenes (metal/3D‐RGO) were characterized by scanning electron microscopy, X‐ray diffraction, transmission electron microscopy and X‐ray photoelectron spectroscopy (XPS). Cyclic voltammetry and the ion chromatography were performed to investigate the electrochemical performance of the metal/3D‐RGO. The morphology and dispersion of metal/3D‐RGO are 3D structure with amount of interconnected pores with metal NPs loading on the fold. And the Pd0.5‐In0.5/3D‐RGO show excellent surface performance with well dispersion and smallest particle size (12.8 nm). XPS reveal that binding energy of Pd (In) NPs is shifted to negative energy, for the metal lose electrons in metal and combine with C, which is demonstrated in the HNO3 experiment. The peak potential of Pd0.5‐In0.5/3D‐RGO is −0.70 V (vs. Ag/AgCl), which is more positive than In1.0/3D‐RGO (−0.73 V) and Pd1.0/3D‐RGO (−1.2 V). The highest faradaic efficiency (85.3 %) happens in Pd0.5‐In0.5/3D‐RGO at −1.6 V vs. Ag/AgCl. In these experiments, the special structure that metal NPs combine with C and the bimetal NPs give a direction to convert CO2 to formate. 相似文献
12.
Vignesh Athiyarath Kana M. Sureshan 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(2):622-627
Two cases of spontaneous evolution of monomers to linear polymers having novel cross‐laminated topology are reported. We synthesized two peptide monomers N3‐Gly‐Gly‐NH‐CH2‐CCH and N3‐Gly‐Gly‐Gly‐CH2‐CCH and solved their crystal structures by single‐crystal X‐ray diffraction. They adopt H‐bonded crisscrossed layered packing in their crystals such that: (a) the monomers are aligned head‐to‐tail in 1D‐chain‐like arrays and parallel arrangement of such arrays forms a layer; (b) the proximally placed azide and alkyne motifs are in an orientation apt for their regiospecific cycloaddition; (c) each monomer having x peptide bonds is H‐bonded with 2x monomers disposed in intersecting arrangement, which pre‐organize 1D‐chain‐like arrays in adjacent layers in perpendicular orientation. These crystals underwent spontaneous single‐crystal‐to‐single‐crystal (SCSC) polymerization via azide–alkyne cycloaddition reaction to form triazolyl‐polyglycines, at room temperature. The crisscrossed arrangement of monomers in adjacent layers ensured the formation of cross‐laminated polymers. 相似文献
13.
Single Crystal to Single Crystal (SC‐to‐SC) Transformation from a Nonporous to Porous Metal–Organic Framework and Its Application Potential in Gas Adsorption and Suzuki Coupling Reaction through Postmodification
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Rupam Sen Debraj Saha Dr. Subratanath Koner Dr. Paula Brandão Dr. Zhi Lin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(15):5962-5971
A new amino‐functionalized strontium–carboxylate‐based metal–organic framework (MOF) has been synthesized that undergoes single crystal to single crystal (SC‐to‐SC) transformation upon desolvation. Both structures have been characterized by single‐crystal X‐ray analysis. The desolvated structure shows an interesting 3D porous structure with pendent ?NH2 groups inside the pore wall, whereas the solvated compound possesses a nonporous structure with DMF molecules on the metal centers. The amino group was postmodified through Schiff base condensation by pyridine‐2‐carboxaldehyde and palladium was anchored on that site. The modified framework has been utilized for the Suzuki cross‐coupling reaction. The compound shows high activity towards the C?C cross‐coupling reaction with good yields and turnover frequencies. Gas adsorption studies showed that the desolvated compound had permanent porosity and was microporous in nature with a BET surface area of 2052 m2 g?1. The material also possesses good CO2 (8 wt %) and H2 (1.87 wt %) adsorption capabilities. 相似文献
14.
Ultrathin Hexagonal Hybrid Nanosheets Synthesized by Graphene Oxide‐Assisted Exfoliation of β‐Co(OH)2 Mesocrystals
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Suzi Deng Dr. Christie Thomas Cherian Xiao li Liu Hui Ru Tan Li Hsia Yeo Dr. Xiaojiang Yu Prof. Andrivo Rusydi Prof. B. V. R. Chowdari Prof. Hai Ming Fan Prof. Chorng Haur Sow 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(39):12444-12452
In the present study, we report the synthesis of a high‐quality, single‐crystal hexagonal β‐Co(OH)2 nanosheet, exhibiting a thickness down to ten atomic layers and an aspect ratio exceeding 900, by using graphene oxide (GO) as an exfoliant of β‐Co(OH)2 nanoflowers. Unlike conventional approaches using ionic precursors in which morphological control is realized by structure‐directing molecules, the β‐Co(OH)2 flower‐like superstructures were first grown by a nanoparticle‐mediated crystallization process, which results in large 3D superstructure consisting of ultrathin nanosheets interspaced by polydimethoxyaniline (PDMA). Thereafter, β‐Co(OH)2 nanoflowers were chemically exfoliated by surface‐active GO under hydrothermal conditions into unilamellar single‐crystal nanosheets. In this reaction, GO acts as a two‐dimensional (2D) amphiphile to facilitate the exfoliation process through tailored interactions between organic and inorganic molecules. Meanwhile, the on‐site conjugation of GO and Co(OH)2 promotes the thermodynamic stability of freestanding ultrathin nanosheets and restrains further growth through Oswald ripening. The unique 2D structure combined with functionalities of the hybrid ultrathin Co(OH)2 nanosheets on rGO resulted in a remarkably enhanced lithium‐ion storage performance as anode materials, maintaining a reversible capacity of 860 mA h g?1 for as many as 30 cycles. Since mesocrystals are ubiquitous and rich in morphological diversity, the strategy of the GO‐assisted exfoliation of mesocrystals developed here provides an opportunity for the synthesis of new functional nanostructures that could bear importance in clean renewable energy, catalysis, photoelectronics, and photonics. 相似文献
15.
Polymorphs α, β, and γ of Ga2O3 having hexagonal (corundum‐type), monoclinic and cubic (spinel‐type) structure, respectively, were prepared in a high‐surface‐area form, and characterized by powder X‐ray diffraction. Nitrogen adsorption at 77 K showed these gallia samples to have specific surface areas of 77 (α‐Ga2O3), 40 (β‐Ga2O3) and 120 m2 g?1 (γ‐Ga2O3). Fourier transform infrared spectroscopy of adsorbed carbon monoxide (at 77 K) and pyridine (at room temperature) showed that the three gallia polymorphs have a very similar surface Lewis acidity, regardless of their different crystal structures. This Lewis acidity was assigned, mainly, to coordinatively unsaturated tetrahedral Ga3+ ions situated on the surface of the small crystallites which constitute the different metal oxide varieties. Ga3+···CO adducts formed after CO adsorption gave (in all cases) a characteristic C–O stretching band at 2195–2200 cm?1, while Lewis‐type adducts formed with adsorbed pyridine were characterized by IR absorption bands at 1610–1612 and 1446–1450 cm?1. The three (partially hydroxylated) gallia polymorphs showed also a very weak Brønsted acidity, which they manifested by forming hydrogen‐bonded adducts with both CO and pyridine; however no protonation of adsorbed pyridine occurred. 相似文献
16.
Ling Wu Jie Zheng Liang Wang Xunhui Xiong Yanyan Shao Gang Wang Jeng‐Han Wang Shengkui Zhong Minghong Wu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(3):821-825
Nanostructured‐alloy‐type anodes have received great interest for high‐performance lithium‐ion batteries (LIBs). However, these anodes experience huge volume fluctuations during repeated lithiation/delithiation and are easily pulverized and subsequently form aggregates. Herein, an efficient method to stabilize alloy‐type anodes by creating defects on the surface of the metal oxide support is proposed. As a demonstration, PPy‐encapsulated SnS2 nanosheets supported on defect‐rich TiO2 nanotubes were produced and investigated as an anode material for LIBs. Both experimental results and theoretical calculations demonstrate that defect‐rich TiO2 provides more chemical adhesions to SnS2 and discharge products, compared to defect‐poor TiO2, and then effectively stabilizes the electrode structure. As a result, the composite exhibits an unprecedented cycle stability. This work paves the way to designing durable and active nanostructured‐alloy‐type anodes on oxide supports. 相似文献
17.
Surfaces of poly(vinyl methyl ether) (PVME), poly(vinyl methyl ketone) (PVMK), and poly(methyl methacrylate) (PMMA) were covered with different thicknesses of nickel with a metal‐vapor‐condensation method, and the metal–polymer interfaces were analyzed by X‐ray photoelectron spectroscopy. In the very first steps of the metalization, it was found that a systematic degradation of the polymer surface occurs through CO or CO2 losses, depending on the polymer functionalities. Then, at the interface with the polymer, the condensed metal reacts by oxidization with the oxygen atoms that are still available after the surface degradation. Nickel oxide is then formed at the interface, whatever the nature of the initial polymer functional group. These new oxide species are not chemically bonded to the polymer structure, and their formation is not affected by the type of bond existing between oxygen and carbon atoms in the original polymer. Finally, the accumulation of metal on the substrate induces an amorphization of the polymer carbon structure because thermal energy is transferred from the metal coating to the polymer. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 40: 82–94, 2002 相似文献
18.
Growth of Single‐Layered Two‐Dimensional Mesoporous Polymer/Carbon Films by Self‐Assembly of Monomicelles at the Interfaces of Various Substrates
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Yin Fang Dr. Yingying Lv Jing Tang Hao Wu Dingsi Jia Dr. Dan Feng Biao Kong Yongcheng Wang Dr. Ahmed A. Elzatahry Prof. Daifallah Al‐Dahyan Prof. Qichun Zhang Prof. Gengfeng Zheng Prof. Dongyuan Zhao 《Angewandte Chemie (International ed. in English)》2015,54(29):8425-8429
Single‐layered two‐dimensional (2D) ultrathin mesoporous polymer/carbon films are grown by self‐assembly of monomicelles at the interfaces of various substrates, which is a general and common modification strategy. These unconventional 2D mesoporous films possess only a single layer of mesopores, while the size of the thin films can grow up to inch size in the plane. Free‐standing transparent mesoporous carbon ultrathin films, together with the ordered mesoporous structure on the substrates of different compositions (e.g. metal oxides, carbon) and morphologies (e.g. nanocubes, nanodiscs, flexible and patterned substrates) have been obtained. This strategy not only affords controllable hierarchical porous nanostructures, but also appends the easily modified and multifunctional properties of carbon to the primary substrate. By using this method, we have fabricated Fe2O3–mesoporous carbon photoelectrochemical biosensors, which show excellent sensitivity and selectivity for glutathione. 相似文献
19.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(6):1670-1674
An area‐selective atomic layer deposition (AS‐ALD) method is described to construct oxide nanotraps to anchor Pt nanoparticles (NPs) on Al2O3 supports. The as‐synthesized catalysts have exhibited outstanding room‐temperature CO oxidation activity, with a significantly lowered apparent activation energy (ca. 22.17 kJ mol−1) that is half that of pure Pt catalyst with the same loading. Furthermore, the structure shows excellent sintering resistance with the high catalytic activity retention up to 600 °C calcination. The key feature of the oxide nanotraps lies in its ability to anchor Pt NPs via strong metal–oxide interactions while still leaving active metal facets exposed. Our reported method for forming such oxide structure with nanotraps shows great potential for the simultaneous enhancement of thermal stability and activity of precious metal NPs. 相似文献
20.
My Research History on the Chemical Standpoint—From Molecular Structure to Surface Science
下载免费PDF全文
![点击此处可从《Chemical record (New York, N.Y.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Yoshitada Murata 《Chemical record (New York, N.Y.)》2015,15(3):557-594
The structure of molecules using gas electron diffraction (GED) was my graduate study. However, I was making a new apparatus for precise measurements by GED and formulated a scheme for the least‐squares analysis for a smooth continuous curve of scattering intensity. My research was completely shifted to the solid surface after moving to Gakushuin University, where I briefly studied the liquid structure of CCl4 molecules, and I then moved to the Institute for Solid State Physics, the University of Tokyo. My studies of surface science were focused on the electronic properties and related phenomena, and various experimental methods were developed. The plasmon dispersions elucidated the initial oxidation of aluminum and one‐dimensional metal on Si(001)2 × 1–K. Irreversible phase transition was discovered on MgO(001) using the LEED Kikuchi pattern. The electronic structure of the dislocation was observed on MgO(001) by the electron time‐of‐flight method. The phase transition on Si(001) and the rotational epitaxy in a K monoatomic layer on Cu(001) were found. Next, I changed to studies of the dynamical phenomena on the surface, where very low energy reactive ion scattering on metal surfaces and laser‐induced desorption caused by electronic transition of NO and CO molecules from metal surfaces were observed, and the hydrogen atom location at the surface and interface was measured with a high depth resolution using a resonance nuclear reaction of 1H + 15N2+ at 6.385 MeV. Finally, I moved to the University of Electro‐Communications and studied thin single‐crystal oxide layers on transition metals, in which the band‐gap narrowing was found, and then a Pt monoatomic layer was prepared on the α‐Al2O3 film. 相似文献