The Use of Lanthanum Ions and Chitosan for Boron Elimination from Aqueous Solutions

Boron is an essential element for plants and living organisms; however, it can be harmful if its concentration in the environment is too high. In this paper, lanthanum(III) ions were introduced to the structure of chitosan via an encapsulation technique and the obtained hydrogel (La-CTS) was used for the elimination of the excess of B(III) from modelling solutions. The reaction between boric acid and hydroxyl groups bound to the lanthanum coordinated by chitosan active centres was the preponderant mechanism of the bio-adsorption removal process. The results demonstrated that La-CTS removed boric acid from the aqueous solution more efficiently than either lanthanum hydroxide or native chitosan hydrogel, respectively. When the initial boron concentration was 100 mg/dm3, the maximum adsorption capacity of 11.1 ± 0.3 mg/g was achieved at pH 5 and the adsorption time of 24 h. The successful introduction of La(III) ions to the chitosan backbone was confirmed by Scanning Electron Microscopy with Energy Dispersive X-Ray Spectroscopy, Fourier-Transform Infrared Spectroscopy, X-Ray Diffraction, X-ray Photoelectron Spectroscopy, and Inductively Coupled Plasma Optical Emission Spectroscopy. Due to its high-performance boron adsorption-desorption cycle and convenient form, La-CTS seems to be a promising bio-adsorbent for water treatment.

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Chitosan Hydrogel Beads Supported with Ceria for Boron Removal

International Journal of Molecular Sciences ◽

10.3390/ijms20071567 ◽

2019 ◽

Vol 20 (7) ◽

pp. 1567 ◽

Cited By ~ 3

Author(s):

Joanna Kluczka ◽

Gabriela Dudek ◽

Alicja Kazek-Kęsik ◽

Małgorzata Gnus

Keyword(s):

Aqueous Solutions ◽

Boric Acid ◽

Inductively Coupled Plasma ◽

High Efficiency ◽

Optical Emission ◽

Freundlich Isotherm ◽

Maximum Adsorption Capacity ◽

Hydroxyl Groups ◽

Chitosan Hydrogel ◽

Chitosan Beads

In this study, a chitosan hydrogel supported with ceria (labelled Ce-CTS) was prepared by an encapsulation technique and used for the efficient removal of excess B(III) from aqueous solutions. The functionalisation of chitosan with Ce(IV) and the improvement in the adsorptive behaviour of the hydrogel were determined by SEM-EDS, FTIR, XRD, and inductively coupled plasma optical emission spectrometer (ICP-OES) analyses and discussed. The results demonstrate that Ce-CTS removes boric acid from aqueous solutions more efficiently than either cerium dioxide hydrate or raw chitosan beads, the precursors of the Ce-CTS biosorbent. The maximum adsorption capacity of 13.5 ± 0.9 mg/g was achieved at pH 7 after 24 h. The equilibrium data of boron adsorption on Ce-CTS fitted the Freundlich isotherm model, while the kinetic data followed the Elovich pseudo-second-order model, which indicated that the process was non-homogeneous. The dominant mechanism of removal was the reaction between boric acid molecules and hydroxyl groups bound to the ceria chelated by chitosan active centres. Due to its high efficiency in removing boron, good regeneration capacity and convenient form, Ce-CTS may be considered a promising biosorbent in water purification.

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Towards chemically neutral carbon cleaning processes: plasma cleaning of Ni, Rh and Al reflective optical coatings and thin Al filters for free-electron lasers and synchrotron beamline applications

Journal of Synchrotron Radiation ◽

10.1107/s1600577518014017 ◽

2018 ◽

Vol 25 (6) ◽

pp. 1642-1649 ◽

Cited By ~ 2

Author(s):

Harol Moreno Fernández ◽

Marco Zangrando ◽

Guillaume Sauthier ◽

Alejandro R. Goñi ◽

Vincent Carlino ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Free Electron ◽

Inductively Coupled Plasma ◽

High Performance ◽

Extreme Ultraviolet ◽

Filter Material ◽

Gas Mixture ◽

Carbon Contamination ◽

X Ray ◽

Chemical Surface

The choice of a reflective optical coating or filter material has to be adapted to the intended field of application. This is mainly determined by the required photon energy range or by the required reflection angle. Among various materials, nickel and rhodium are common materials used as reflective coatings for (soft) X-ray mirrors. Similarly, aluminium is one of the most commonly used materials for extreme ultraviolet and soft X-ray transmission filters. However, both of these types of optics are subject to carbon contamination, which can be increasingly problematic for the operation of the high-performance free-electron laser and synchrotron beamlines. As an attempt to remove this type of contamination, an inductively coupled plasma source has been used in conjunction with N2/O2/H2 and N2/H2 feedstock gas plasmas. Results from the chemical surface analysis of the above materials before and after plasma treatment using X-ray photoelectron spectroscopy are reported. It is concluded that a favorable combination of an N2/H2 plasma feedstock gas mixture leads to the best chemical surface preservation of Ni, Rh and Al while removing the carbon contamination. However, this feedstock gas mixture does not remove C contamination as rapidly as, for example, an N2/O2/H2 plasma which induces the surface formation of NiO and NiOOH in Ni and RhOOH in Rh foils. As an applied case, the successful carbon removal from ultrathin Al filters previously used at the FERMI FEL1 using an N2/H2 plasma is demonstrated.

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Detoxification, Active Uptake, and Intracellular Accumulation of Chromium Species by a Methane-Oxidizing Bacterium

Applied and Environmental Microbiology ◽

10.1128/aem.00947-20 ◽

2020 ◽

Vol 87 (2) ◽

Author(s):

Salaheldeen Enbaia ◽

Abdurrahman Eswayah ◽

Nicole Hondow ◽

Philip H. E. Gardiner ◽

Thomas J. Smith

Keyword(s):

Photoelectron Spectroscopy ◽

Inductively Coupled Plasma ◽

High Performance ◽

Low Cost ◽

Cell Fractionation ◽

Methylococcus Capsulatus ◽

Chromium Species ◽

Content Type ◽

X Ray ◽

Chromium Vi

ABSTRACT Despite the wide-ranging proscription of hexavalent chromium, chromium(VI) remains among the major polluting heavy metals worldwide. Aerobic methane-oxidizing bacteria are widespread environmental microorganisms that can perform diverse reactions using methane as the feedstock. The methanotroph Methylococcus capsulatus Bath, like many other microorganisms, detoxifies chromium(VI) by reduction to chromium(III). Here, the interaction of chromium species with M. capsulatus Bath was examined in detail by using a range of techniques. Cell fractionation and high-performance liquid chromatography–inductively coupled plasma mass spectrometry (HPLC–ICP-MS) indicated that externally provided chromium(VI) underwent reduction and was then taken up into the cytoplasmic and membranous fractions of the cells. This was confirmed by X-ray photoelectron spectroscopy (XPS) of intact cultures that indicated negligible chromium on the surfaces of or outside the cells. Distribution of chromium and other elements within intact and sectioned cells, as observed via transmission electron microscopy (TEM) combined with energy-dispersive X-ray spectroscopy (EDX) and electron energy loss spectroscopy (EELS), was consistent with the cytoplasm/membrane location of the chromium(III), possibly as chromium phosphate. The cells could also take up chromium(III) directly from the medium in a metabolism-dependent fashion and accumulate it. These results indicate a novel pattern of interaction with chromium species distinct from that observed previously with other microorganisms. They also suggest that M. capsulatus and similar methanotrophs may contribute directly to chromium(VI) reduction and accumulation in mixed communities of microorganisms that are able to perform methane-driven remediation of chromium(VI). IMPORTANCE M. capsulatus Bath is a well-characterized aerobic methane-oxidizing bacterium that has become a model system for biotechnological development of methanotrophs to perform useful reactions for environmental cleanup and for making valuable chemicals and biological products using methane gas. Interest in such technology has increased recently owing to increasing availability of low-cost methane from fossil and biological sources. Here, it is demonstrated that this versatile methanotroph can reduce the toxic contaminating heavy metal chromium(VI) to the less toxic form chromium(III) while accumulating the chromium(III) within the cells. This is expected to diminish the bioavailability of the chromium and make it less likely to be reoxidized to chromium(VI). Thus, M. capsulatus has the capacity to perform methane-driven remediation of chromium-contaminated water and other materials and to accumulate the chromium in the low-toxicity chromium(III) form within the cells.

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Microwave Assisted Novel Efficient Pd-free Catalyst for Suzuki C-C Coupling Reaction

10.20944/preprints201809.0458.v2 ◽

2019 ◽

Author(s):

Ghalia Alzhrani ◽

Nesreen Ahmed ◽

Elham Aazam ◽

Mohamed Mokhtar ◽

Tamer Saleh

Keyword(s):

Photoelectron Spectroscopy ◽

Inductively Coupled Plasma ◽

Coupling Reaction ◽

Optical Emission ◽

Nickel Catalysts ◽

Aryl Halides ◽

Precipitation Method ◽

Coupling Reactions ◽

Nickel Ions ◽

X Ray

Suzuki cross-coupling reaction has developed one of the furthermost effectual approaches for the synthesis of biaryls or substituted aromatic moieties from aryl halides and arylboronic acids with a palladium-catalyst in the past two era’s. Herein, Pd-free layered double hydroxide containing nickel catalysts were prepared by co-precipitation method under ultrasonic irradiation and N2 atmosphere with different molar ratios of Ni: Mg: Al and coded as (1NiLDHs-Dr), (1.5NiLDHs-Dr) and (2NiLDHs-Dr). A series of reduced catalysts under 5%H2/N2 at different temperatures were coded as 1NiLDHs-R200, 1.5NiLDHs-R200 and 2NiLDHs-R200. As-synthesized 2NiLDHs-Dr was the superlative catalyst when coupling different aryl halides with different boronic acids derivatives. Deep investigation of all catalysts was done using different techniques such as inductively coupled plasma optical emission spectroscopy (ICP-OES), x-ray photoelectron spectroscopy (XPS), powder x-ray diffraction (XRD), thermogravimetric analyses (TGA), Fourier transfer infrared (FTIR), scanning electron microscope (SEM) connected with energy dispersive x-ray (EDX) and N2-physisorption at -196 ℃. The results attained verified that ɑ-Ni(OH)2 was fashioned for 2NiLDHs-Dr catalyst and the enclosure of nickel ions in the cationic sheet of layered structure were responsible for the fascinating catalytic efficacy rather than the basic nature of material. The Ni-containing LDHs catalysts encourage forthcoming studies in Pd-free catalyzed C-C coupling reactions.

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Revealing the reactivity of the Iridium trioxide intermediate for the oxygen evolution reaction in acidic media

10.26434/chemrxiv.8040380.v1 ◽

2019 ◽

Author(s):

Paul Pearce ◽

Chunzhen Yang ◽

Antonella Iadecola ◽

Juan Rodriguez-Carvajal ◽

Gwenaëlle Rousse ◽

...

Keyword(s):

Oxygen Evolution ◽

Photoelectron Spectroscopy ◽

Oxygen Evolution Reaction ◽

Inductively Coupled Plasma ◽

Optical Emission ◽

Charge Compensation ◽

Acidic Media ◽

X Ray ◽

Inductively Coupled ◽

Reaction With Water

We report a strategy to isolate IrO3 as an intermediate for the oxygen evolution reaction (OER). Its reactivity is studied using X-ray absorption spectroscopy, X-ray and neutron diffraction and X-ray photoelectron spectroscopy. Its stability is assessed by using on-line mass spectroscopy and inductively coupled plasma optical emission spectroscopy and presented herein. Upon reaction with water in acidic conditions, we could observe the formation of a new protonated iridate phase of composition H2IrO3. Coupling OER measurements and dissolution rate determination, we could show that its activity and stability are governed by a yet ill-described charge compensation mechanism enlisting reversible bulk proton insertion inside the catalyst structure. This singular property enables an enhanced activity and stability towards dissolution compared to the stellar IrOx/SrIrO3 catalyst. Such a finding opens the route towards the design of new OER catalysts enlisting proton insertion that could be competitive for water splitting in acidic media.

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Microwave Assisted Novel Efficient Pd-free Catalyst for Suzuki C-C Coupling Reaction

10.20944/preprints201809.0458.v1 ◽

2018 ◽

Author(s):

Ghalia Alzhrani ◽

Nesreen Ahmed ◽

Elham Aazam ◽

Mohamed Mokhtar

Keyword(s):

Photoelectron Spectroscopy ◽

Inductively Coupled Plasma ◽

Coupling Reaction ◽

Optical Emission ◽

Nickel Catalysts ◽

Aryl Halides ◽

Precipitation Method ◽

Coupling Reactions ◽

Nickel Ions ◽

X Ray

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Palladium Supported on Carbon Nanotubes as a High-Performance Catalyst for the Dehydrogenation of Dodecahydro-N-ethylcarbazole

Catalysts ◽

10.3390/catal8120638 ◽

2018 ◽

Vol 8 (12) ◽

pp. 638 ◽

Cited By ~ 6

Author(s):

Mengyan Zhu ◽

Lixin Xu ◽

Lin Du ◽

Yue An ◽

Chao Wan

Keyword(s):

Carbon Nanotubes ◽

Hydrogen Storage ◽

Photoelectron Spectroscopy ◽

Inductively Coupled Plasma ◽

High Performance ◽

Fossil Fuels ◽

Hydrogen Release ◽

Hydrogen Energy ◽

Widespread Application ◽

X Ray

Hydrogen storage in the form of liquid organic hydrides, especially N-ethylcarbazole, has been regarded as a promising technology for substituting traditional fossil fuels owing to its unique merits such as high volumetric, gravimetric hydrogen capacity and safe transportation. However, unsatisfactory dehydrogenation has impeded the widespread application of N-ethylcarbazole as ideal hydrogen storage materials in hydrogen energy. Therefore, designing catalysts with outstanding performance is of importance to address this problem. In the present work, for the first time, we have synthesized Pd nanoparticles immobilized on carbon nanotubes (Pd/CNTs) with different palladium loading through an alcohol reduction technique. A series of characterization technologies, such as X-ray diffraction (XRD), inductively coupled plasma-atomic emission spectrometer (ICP-AES), X-ray photoelectron spectroscopy (XPS) and transmission electron spectroscopy (TEM) were adopted to systematically explore the structure, composition, surface properties and morphology of the catalysts. The results reveal that the Pd NPs with a mean diameter of 2.6 ± 0.6 nm could be dispersed uniformly on the surface of CNTs. Furthermore, Pd/CNTs with different Pd contents were applied in the hydrogen release of dodecahydro-N-ethylcarbazole. Among all of the catalysts tested, 3.0 wt% Pd/CNTs exhibited excellent catalytic performance with the conversion of 99.6% producing 5.8 wt% hydrogen at 533 K, low activation energy of 43.8 ± 0.2 kJ/mol and a high recycling stability (>96.4% conversion at 5th reuse).

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Rhodium Nanoparticles Stabilized by PEG-Tagged Imidazolium Salts as Recyclable Catalysts for the Hydrosilylation of Internal Alkynes and the Reduction of Nitroarenes

Catalysts ◽

10.3390/catal10101195 ◽

2020 ◽

Vol 10 (10) ◽

pp. 1195

Author(s):

Guillem Fernández ◽

Roser Pleixats

Keyword(s):

Photoelectron Spectroscopy ◽

Inductively Coupled Plasma ◽

Optical Emission ◽

Water Soluble ◽

X Ray ◽

Rhodium Nanoparticles ◽

Inductively Coupled ◽

Transmission Electron ◽

Internal Alkynes ◽

Recyclable Catalysts

PEGylated imidazolium (bromide and tetrafluoroborate) and tris-imidazolium (bromide) salts containing triazole linkers have been used as stabilizers for the preparation of water-soluble rhodium(0) nanoparticles by reduction of rhodium trichloride with sodium borohydride in water at room temperature. The nanomaterials have been characterized (Transmission Electron Microscopy, Electron Diffraction, X-ray Photoelectron Spectroscopy, Inductively Coupled Plasma-Optical Emission Spectroscopy). They proved to be efficient and recyclable catalysts for the stereoselective hydrosilylation of internal alkynes, in the presence or absence of solvent, and in the reduction of nitroarenes to anilines with ammonia-borane as hydrogen donor in aqueous medium (1:4 tetrahydrofuran/water).

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SYNTHESIS AND CHARACTERIZATION OF TERNARY AL-C-N COMPOUND

International Journal of Modern Physics B ◽

10.1142/s0217979202010993 ◽

2002 ◽

Vol 16 (06n07) ◽

pp. 1132-1137 ◽

Cited By ~ 9

Author(s):

N. JIANG ◽

S. XU ◽

K. N. OSTRIKOV ◽

E. L. TSAKADZE ◽

J. D. LONG ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Inductively Coupled Plasma ◽

Optical Emission ◽

Flow Rate Ratio ◽

In Situ Observation ◽

X Ray Diffraction ◽

X Ray ◽

Inductively Coupled

An attempt for modification of carbon nitride material by introduction of Al to form a ternary Al-C-N compound in a thin film deposited using inductively coupled plasma (ICP) assisted DC magnetron sputtering is reported. Optical emission spectroscopy (OES) is used for in-situ observation and identification of reactive species. The films were characterized using x-ray photoelectron spectroscopy (XPS) and x-ray diffraction spectroscopy (XRD). The results indicate that C-N bond is formed in the plasma. The XPS narrow scam spectra confirm the existence of C-Al, sp2C-N and sp3C-N bonds. Elemental proportion of carbon increases with the CH4/N2 flow rate ratio, and has a tendency to saturate. The film is dominated by c-AlN (111), mixed with Al4C3 and AlCN ternary compound.

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Spinel to Rock-Salt Transformation in High Entropy Oxides with Li Incorporation

Electrochem ◽

10.3390/electrochem1010007 ◽

2020 ◽

Vol 1 (1) ◽

pp. 60-74 ◽

Cited By ~ 3

Author(s):

Junbo Wang ◽

David Stenzel ◽

Raheleh Azmi ◽

Saleem Najib ◽

Kai Wang ◽

...

Keyword(s):

Rock Salt ◽

Photoelectron Spectroscopy ◽

Inductively Coupled Plasma ◽

Electrode Materials ◽

Lithium Ion ◽

Optical Emission ◽

Attenuated Total Reflection ◽

X Ray ◽

High Entropy ◽

Infinite Variety

High entropy oxides (HEOs) constitute a promising class of materials with possibly new and largely unexplored properties. The virtually infinite variety of compositions (multi-element approach) for a single-phase structure allows the tailoring of their physical properties and enables unprecedented materials design. Nevertheless, this level of versatility renders their characterization as well as the study of specific processes or reaction mechanisms challenging. In the present work, we report the structural and electrochemical behavior of different multi-cationic HEOs. Phase transformation from spinel to rock-salt was observed upon incorporation of monovalent Li+ ions, accompanied by partial oxidation of certain elements in the lattice. This transition was studied by X-ray diffraction, inductively coupled plasma-optical emission spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, and attenuated total reflection infrared spectroscopy. In addition, the redox behavior was probed using cyclic voltammetry. Especially, the lithiated rock-salt structure HEOs were found to exhibit potential for usage as negative and positive electrode materials in rechargeable lithium-ion batteries.

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