Determination of surface hydroxyl groups on glassy carbon with x-ray photoelectron spectroscopy preceded by chemical derivatization

1987 ◽  
Vol 59 (3) ◽  
pp. 396-399 ◽  
Author(s):  
W. G. Collier ◽  
T. P. Tougas
Keyword(s):  
Glassy Carbon ◽  
Photoelectron Spectroscopy ◽  
Hydroxyl Groups ◽  
Chemical Derivatization ◽  
X Ray ◽  
Surface Hydroxyl ◽  
Surface Hydroxyl Groups

Self Terminating Reaction of Dipivaloylmethanate Complexes with Hydroxyl Groups on Oxide Surface

1991 ◽  
Vol 222 ◽  
Author(s):  
Rika Sekine ◽  
Maki Kawai ◽  
Kiyotaka Asakura ◽  
Yasuhiro Iwasawa
Keyword(s):  
Fine Structure ◽  
Photoelectron Spectroscopy ◽  
Oxide Surface ◽  
Hydroxyl Groups ◽  
Adsorbed Species ◽  
Oh Groups ◽  
X Ray ◽  
Surface Hydroxyl ◽  
Surface Hydroxyl Groups ◽  
X Ray Absorption

ABSTRACTWe have already reported that copper and calcium dipivaloylmethanates [Cu(DPM)2 and Ca(DPM)2 ] reacts selectively and stoichiometrically with surface hydroxyl groups (OH) on SiO2. In order to clarify the structure of the adsorbed species and the origin of the reaction between M(DPM)2 (M=Cu and Ca) and OH groups, the surface adsorbed species are studied by infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS), and the extended X-ray absorption fine structure (EXAFS). As a result, it was found that H from surface OH has moved into M(DPM)2 after the adsorption, where the four oxygen coordinated structure around Cu still exists in the adsorbed Cu(DPM)2. Introducing water vapor at 673 K to this surface results in the removal of ligand DPM from the adsorbed Cu(DPM)2. At 673 K, Cu atoms decomposed from the adsorbates aggregated on the surface. This fact supports that the interaction between the adsorbed Cu(DPM)2 and SiO2 surface is originated from that between the ligands and the surface.

scholarly journals Preparation of Ni Doped ZnO-TiO2Composites and Their Enhanced Photocatalytic Activity

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaowen Zou ◽  
Xiaoli Dong ◽  
Limei Wang ◽  
Hongchao Ma ◽  
Xinxin Zhang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Visible Region ◽  
Hydroxyl Groups ◽  
X Ray ◽  
Surface Hydroxyl ◽  
Simulated Solar Light ◽  
Transmission Electron ◽  
Doped Zno

Herein, Ni doped ZnO-TiO2composites were prepared by facile sol-gel approach and were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-visible diffuse reflectance spectroscopy (UV-Vis DRS), X-ray photoelectron spectroscopy (XPS), and photoluminescence spectroscopy (PL). The results indicated that the Ni ions can be incorporated into the lattice of TiO2structure and replace Ti. The introduction of Ni expanded light absorption of TiO2to visible region, increased amount of surface hydroxyl groups and physically adsorbed oxygen (as the electronic scavenges), and then enhanced separation rate of photogenerated carriers. The photodegradation test of reactive brilliant blue (KN-R) under simulated solar light indicated that Ni doped ZnO-TiO2composites have better photocatalytic activities, as compared to those of TiO2and ZnO-TiO2.

Grafted organic derivatives of kaolinite: I. Synthesis, chemical and rheological characterization

Clay Minerals ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 537-546 ◽  
Author(s):  
J. E. F. C. Gardolinski ◽  
G. Lagaly
Keyword(s):  
Alkyl Chain ◽  
Hydroxyl Groups ◽  
Rheological Characterization ◽  
Aqueous Dispersions ◽  
X Ray ◽  
Surface Hydroxyl ◽  
Surface Hydroxyl Groups ◽  
Transmission Electron ◽  
Yield Value ◽  
Derivatives Of

AbstractSeveral new interlayer-grafted derivatives of kaolinite were synthesized by esterification of inner-surface hydroxyl groups with alkanols, diols and glycol mono-ethers starting with the dimethyl sulphoxide intercalate. The derivatives were characterized by X-ray powder diffractometry, thermal analysis, Fourier transform infrared spectroscopy and transmission electron microscopy. The grafted molecules are arranged in monolayers between the kaolinite layers, with typical basal spacings of ~11.3 Å. Rheological studies of aqueous dispersions of the modified kaolinites revealed an exponential increase of the yield value and apparent viscosity with increasing alkyl chain length of the grafted molecules.

SURFACE-INITIATED ATOM TRANSFER RADICAL POLYMERIZATION OF HYDROXYETHYL ACRYLATE FROM ACTIVATED CARBON POWDER WITH HOMOGENIZED SURFACE GROUPS

2007 ◽  
Vol 14 (02) ◽  
pp. 269-275 ◽  
Author(s):  
PENG LIU ◽  
TINGMEI WANG
Keyword(s):  
Activated Carbon ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Photoelectron Spectroscopy ◽  
Water System ◽  
Carbon Powder ◽  
Hydroxyl Groups ◽  
Atom Transfer ◽  
Surface Hydroxyl ◽  
Surface Hydroxyl Groups

The well-defined poly(hydroxyethyl acrylate) (PHEA) brushes were grafted from the surfaces of the activated carbon (AC) powder with the controlled/"living" radical polymerization technique. First, surface functional groups of the AC powder were homogenized to hydroxyl groups by oxidizing with nitric acid and then reducing with lithium tetrahydroaluminate ( LiAlH 4) at first. Second, the surface hydroxyl groups were treated with bromoacetylbromide, and the bromoacetyl groups were introduced. And in the third step, the bromoacetyl activated carbon ( BrA-AC ) powder were used as macro-initiators for the surface-initiated atom transfer radical polymerization (SI-ATRP) of hydroxyethyl acrylate (HEA) in the presence of 1,10-phenanthroline and Cu(I)Br as catalyst in a water system. The graft parameters calculated from the elemental analyses (EA) results, conversion of monemer (C%) and percentage of grafting (PG%) were 5.74% and 28.7%, respectively, after polymerizing for 5 h. The graft polymerizations exhibited the characteristics of a controlled/"living" polymerization, and no homopolymer was found in the proposed polymerizing process. The preparation procedure of the poly(hydroxyethyl acrylate) grafted activated carbon (PHEA-AC) powder was also investigated by X-ray photoelectron spectroscopy (XPS). The PHEA-AC powder is expected to be used as selective adsorbents because of their abundant homogenized surface hydroxyl groups.

scholarly journals Preparation and Application of Keggin Silicomolybdic acid Modified Electrode

2020 ◽  
Author(s):  
Miao Liu ◽  
Mingxuan Jia ◽  
Dong Hui Li
Keyword(s):  
Glassy Carbon Electrode ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
Photoelectron Spectroscopy ◽  
Limit Of Detection ◽  
Differential Pulse ◽  
Carbon Electrode ◽  
X Ray ◽  
Linear Relationships

Abstract An innovative method for the determination of isoniazid tablets is studied through electrochemical method for the modification of glassy carbon electrode (GCE). Polyoxomolybdate, with stable structures, has not been widely used for the determination of substance. In this study, the mentioned polyoxomolybdate was characterized by Fourier transform infrared spectroscopy (FT-IR), UV-vis, X-ray diffraction (XRD), Atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS), and used to modify the glassy carbon electrode. The electrochemical performance of the polyoxomolybdate@GCE was investigated with cyclic voltammetry (CV) and differential pulse voltammetry (DPV), compared with the unmodified electrode, the proposed polyoxomolybdate modified electrode exhibited strong electro-catalytic activities towards isoniazid (INH). Under the optimized conditions, there was linear relationships between the DPV peak currents and the concentrations in the range of 1 × 10 -7 g/L to 3 × 10 -7 g/L for INH (R 2 = 0.9979), with the limit of detection (LOD) of 0.024 μg/L (based on S/N = 3). The modified electrode has proper reproducibility (RSD < 5%), stability, response time (< 3 min) and lifetime (up to 6 days).

scholarly journals Novel Hybrid Materials And Their Applications

2021 ◽  
Author(s):  
◽  
Aaron Charles Small
Keyword(s):  
Quantum Dots ◽  
Hydrogen Bonding ◽  
Magnetite Nanoparticles ◽  
Uv Light ◽  
Precipitation Method ◽  
Hydroxyl Groups ◽  
Cellulose Fibres ◽  
X Ray ◽  
Surface Hydroxyl ◽  
Surface Hydroxyl Groups

<p>The development of novel hybrid materials of cellulose fibres and substrates with nanoparticles, conducting polymers and quantum dots, opens up novel application for new packaging materials and paper based products for the ‘smart packaging’ and ‘functional products’ areas that are emerging in the paper and packaging industries. Examples of these materials which have been developed here include cellulose fibres and substrates functionalised with magnetic nanoparticles, electrically conducting polypyrrole, and photoluminescent zinc sulfide quantum dots.  Such materials were synthesised and then characterised using Alternating Gradient Magnetometry (AGM), Atomic Absorption Spectroscopy (AA), Cotec Profilometer Measurements, DC Conductivity Measurements, Photoluminescence Spectroscopy (PL), Scanning Electron Microscopy (SEM), SQUID Magnetometry, Transmission Electron Microscopy (TEM), Vibrational Sample Magnetometry (VSM), X-ray Diffraction (XRD), X-ray Fluorescence (XRF) and X-ray Photoelectron Spectroscopy (XPS).  Ferrimagnetic magnetite nanoparticles (particle size 12-26 nm) were synthesised by a simple aqueous precipitation method and had a magnetic saturation of approximately 60 emu g⁻¹, a coercive field of approximately 12-120 Oe, and a remnant magnetisation of approximately 11 emu g⁻¹.  Magnetite coated Kraft fibres (1.2 – 3.15 wt. % Fe) were synthesised by adding a colloidal suspension of magnetite nanoparticles to a suspension of Kraft fibres. The fibres retained their inherent properties, such as tensile strength and flexibility, but inherited the magnetic properties of the magnetic nanoparticles. The nanoparticles remained unchanged on bonding - presumably through hydrogen bonding between the surface hydroxyl groups of the cellulose and the oxygen present in the magnetite.  Newsprint, Kraft Board and Cotton fabric were coated with polypyrrole using a chemical polymerisation method. SEM shows a complete coating, whereby the fibres are completely encapsulated by the polymer, including individual fibrils. Again, bonding is facilitated through hydrogen bonding between the surface hydroxyl groups of the cellulose and the lone pairs of the nitrogen in the polypyrrole backbone. Samples were doped with p-toluenesulfonic acid to increase conductivity, of which up to 4 S cm⁻¹ was achieved.  The samples were coated with magnetite nanoparticles using a starch binder, and tested for their application in EMI shielding. A maximum shielding effectiveness of 43 % in the 1-18 GHz range and 47 % in the 16-40 GHz range was obtained using cotton fabrics coated with both polypyrrole and magnetite. A synergistic effect is observed on using a polypyrrole and magnetite coating.  Photoluminescent ZnS quantum dots, synthesised using an aqueous precipitation method, were doped with Mn²⁺ and Cu²⁺ to achieve emissions at approximately 600 nm (Mn²⁺) and 530 nm (Cu²⁺) on irradiation with UV light. The quantum dots had a particle size of approximately 2 nm, and were present in the zinc blende phase.  Doped ZnS-coated Kraft fibres (5 – 30 wt. % Zn) were synthesised by a number of methods, the most successful being the ‘in-situ’ method, in which a uniform and complete coating was afforded. The fibres retained their inherent properties, such as tensile strength and flexibility, but inherited the photoluminescent properties of the ZnS quantum dots. The quantum dots remained unchanged on bonding - presumably through hydrogen bonding between the surface hydroxyl groups of the cellulose and the sulfur present in the ZnS quantum dots.  ZnS quantum dots doped with Mn² and Cu²⁺ were successfully formulated for inkjet printing by capping with mercaptosuccinic acid. Upon irradiation with UV light, emissions at approximately 600 nm (Mn²⁺-doped) and 530 nm (Cu²⁺-doped) were observed. These were successfully inkjet printed in intricate patterns onto a number of substrates, including photographic quality inkjet paper, cotton, and wool.</p>

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