LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 9 of total 9

Search options

  1. Article ; Online: Comparative visible-light driven selective oxidation to aldehydes of phenylmethanol (benzyl alcohol) and 4-pyridinylmethanol (4-pyridinecarbinol) on N-TiO

    Samiolo, Luca / Amadelli, Rossano / Maldotti, Andrea / Molinari, Alessandra

    Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology

    2021  Volume 20, Issue 12, Page(s) 1635–1644

    Abstract: Visible light (λ > 420 nm) selective photooxidation of phenylmethanol and 4-pyridinylmethanol in ... ...

    Abstract Visible light (λ > 420 nm) selective photooxidation of phenylmethanol and 4-pyridinylmethanol in CH
    Language English
    Publishing date 2021-11-21
    Publishing country England
    Document type Journal Article
    ZDB-ID 2072584-X
    ISSN 1474-9092 ; 1474-905X
    ISSN (online) 1474-9092
    ISSN 1474-905X
    DOI 10.1007/s43630-021-00137-4
    Database MEDical Literature Analysis and Retrieval System OnLINE

    Full text online

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  2. Article ; Online: EPR spin trapping evidence of radical intermediates in the photo-reduction of bicarbonate/CO2 in TiO2 aqueous suspensions.

    Molinari, Alessandra / Samiolo, Luca / Amadelli, Rossano

    Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology

    2015  Volume 14, Issue 5, Page(s) 1039–1046

    Abstract: Using the EPR spin trapping technique, we prove that simultaneous reactions take place in illuminated suspensions of TiO2 in aqueous carbonate solutions (pH ≈ 7). The adsorbed HCO3(-) is reduced to formate as directly made evident by the detection of ... ...

    Abstract Using the EPR spin trapping technique, we prove that simultaneous reactions take place in illuminated suspensions of TiO2 in aqueous carbonate solutions (pH ≈ 7). The adsorbed HCO3(-) is reduced to formate as directly made evident by the detection of formate radicals (˙CO2(-)). In addition, the amount of OH˙ radicals from the photo-oxidation of water shows a linear dependence on the concentration of bicarbonate, indicating that electron scavenging by HCO3(-) increases the lifetime of holes. In a weakly alkaline medium, photo-oxidation of HCO3(-)/CO3(2-) to ˙CO3(-) interferes with the oxidation of water. A comparative analysis of different TiO2 samples shows that formation of ˙CO2(-) is influenced by factors related to the nature of the surface, once expected surface area effects are accounted for. Modification of the TiO2 surface with noble metal nanoparticles does not have unequivocal benefits: the overall activity improves with Pd and Rh but not with Ru, which favours HCO3(-) photo-oxidation even at pH = 7. In general, identification of radical intermediates of oxidation and reduction reactions can provide useful mechanistic information that may be used in the development of photocatalytic systems for the reduction of CO2 also stored in the form of carbonates.
    MeSH term(s) Bicarbonates/chemistry ; Bicarbonates/radiation effects ; Carbon Dioxide/chemistry ; Carbon Dioxide/radiation effects ; Electron Spin Resonance Spectroscopy ; Fluorescence ; Formates/chemistry ; Formates/radiation effects ; Hydroxyl Radical/chemistry ; Hydroxyl Radical/radiation effects ; Linear Models ; Oxidation-Reduction ; Photochemical Processes ; Spin Trapping ; Surface Properties ; Suspensions ; Titanium/chemistry ; Titanium/radiation effects ; Water/chemistry
    Chemical Substances Bicarbonates ; Formates ; Suspensions ; Water (059QF0KO0R) ; formic acid (0YIW783RG1) ; Carbon Dioxide (142M471B3J) ; titanium dioxide (15FIX9V2JP) ; Hydroxyl Radical (3352-57-6) ; Titanium (D1JT611TNE)
    Language English
    Publishing date 2015-05
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2072584-X
    ISSN 1474-9092 ; 1474-905X
    ISSN (online) 1474-9092
    ISSN 1474-905X
    DOI 10.1039/c4pp00467a
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  3. Article ; Online: An electrochemical and radiotracer investigation on lead dioxide

    Amadelli Rossano / Samiolo Luca / Velichenko Aleksandr B.

    Journal of the Serbian Chemical Society, Vol 78, Iss 12, Pp 2099-

    Influence of deposition current and temperature

    2013  Volume 2114

    Abstract: The properties of electrodeposited PbO2 are sensibly influenced by deposition current and temperature. In particular, tritium radiotracer measurements have demonstrated that protons are incorporated in the bulk of the oxide film and on its surface. The ... ...

    Abstract The properties of electrodeposited PbO2 are sensibly influenced by deposition current and temperature. In particular, tritium radiotracer measurements have demonstrated that protons are incorporated in the bulk of the oxide film and on its surface. The degree of hydration increases with increasing current and decreases with temperature, and is related to the morphological characteristics of the oxide such as roughness measured by changes of the double layer capacity. Conversely, the amount of hydrogen has negligible effects on the number of free carriers evaluated from Mott-Schottky plots. The hydration degree of the surface seems to be an important factor influencing electrocatalytic processes at high potentials such as O2 evolution and O3 formation. On less hydrated, more crystalline PbO2 surfaces the first process is inhibited, and accordingly, the second is favored.
    Keywords lead dioxide ; tritium ; electrodeposition ; electrocatalysis ; Chemistry ; QD1-999
    Language English
    Publishing date 2013-01-01T00:00:00Z
    Publisher Serbian Chemical Society
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  4. Article ; Online: Probing the role of surface energetics of electrons and their accumulation in photoreduction processes on TiO₂.

    Molinari, Alessandra / Maldotti, Andrea / Amadelli, Rossano

    Chemistry (Weinheim an der Bergstrasse, Germany)

    2014  Volume 20, Issue 25, Page(s) 7759–7765

    Abstract: We address the role of the energetics of photogenerated electrons in the reduction of 4-nitrobenzaldehyde on TiO2. This model molecule bears two functional groups featuring different reducibilities. Electrochemistry shows that reduction to 4-aminobenzyl ... ...

    Abstract We address the role of the energetics of photogenerated electrons in the reduction of 4-nitrobenzaldehyde on TiO2. This model molecule bears two functional groups featuring different reducibilities. Electrochemistry shows that reduction to 4-aminobenzyl alcohol occurs in entirely distinct potential ranges. Partial reduction of the -NO2 group, affording 4-aminobenzaldehyde, takes place through surface states at potentials positive of the flatband potential (E(fb)). Dark currents caused by reduction of the aldehyde group are observed only at potentials more negative than E(fb), and the process requires an electron accumulation regime. Photocatalysis with TiO2 suspensions agrees with the electrochemical data. In particular, reduction of the nitro group is a relatively fast process (k=0.059 s(-1)), whereas that of the aldehyde group is slower (k=0.001 s(-1)) and requires electron photoaccumulation. Control of the photogenerated charge is a prospective means for achieving chemoselective reductions.
    Language English
    Publishing date 2014-06-16
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 1478547-x
    ISSN 1521-3765 ; 0947-6539
    ISSN (online) 1521-3765
    ISSN 0947-6539
    DOI 10.1002/chem.201402039
    Database MEDical Literature Analysis and Retrieval System OnLINE

    Full text online

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  5. Article ; Online: Lead dioxide electrodes for high potential anodic processes

    Amadelli Rossano / Velichenko A.B.

    Journal of the Serbian Chemical Society, Vol 66, Iss 11-12, Pp 835-

    2001  Volume 845

    Abstract: Doping of PbO2 by cations (Fe3+, Co2+ and Ni2+), by F- and by cations and F- simultaneously is discussed as a way of improving the stability and electrochemical activity in processes occurring at high potentials. Doping allows the control of the amount ... ...

    Abstract Doping of PbO2 by cations (Fe3+, Co2+ and Ni2+), by F- and by cations and F- simultaneously is discussed as a way of improving the stability and electrochemical activity in processes occurring at high potentials. Doping allows the control of the amount of structural water in an oxide. Radiotracer experiments showed that high electrodeposition current densities favour the segregation of incorporated tritium (protons) at the surface. On the other hand, fluorine doping results in a marked decrease in the amount of surface oxygen species. The influence of doping with metal cations strongly depends on the nature of the metal. Iron behaves like fluorine, while nickel causes an accumulation of surface oxygen species. Doped PbO2 electrodes have quite good activities for the electrogeneration of ozone. In particular, Fe and Co doped PbO2 showed a current efficiency of 15-20%for this process. This result is relevant to our recent studies on “cathodic oxidation”, i.e., an ozone mediated electrochemical method in which an O2 stream is used to sweep theO2/O3 gas mixture produced at a PbO2 anode into the cathodic compartment of the same electrochemical cell containing polluting species.
    Keywords lead dioxide anodes ; doping ; ozone electrogeneration ; Chemistry ; QD1-999
    Language English
    Publishing date 2001-01-01T00:00:00Z
    Publisher Serbian Chemical Society
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  6. Article: Photocatalytic activity of MCM-organized TiO(2) materials in the oxygenation of cyclohexane with molecular oxygen.

    Maldotti, Andrea / Molinari, Alessandra / Amadelli, Rossano / Carbonell, Esther / Garcia, Hermenegildo

    Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology

    2008  Volume 7, Issue 7, Page(s) 819–825

    Abstract: The photooxygenation of cyclohexane by molecular oxygen has been investigated on two mesoporous TiO(2) materials, which have been prepared using colloidal nanoparticles as building blocks. One of the structured systems (mpTiO(2)-50) is a mixture of 50% ... ...

    Abstract The photooxygenation of cyclohexane by molecular oxygen has been investigated on two mesoporous TiO(2) materials, which have been prepared using colloidal nanoparticles as building blocks. One of the structured systems (mpTiO(2)-50) is a mixture of 50% TiO(2) and 50% SiO(2); the second one (mpTiO(2)-100) is constituted by 100% of TiO(2). Both mpTiO(2)-100 and mpTiO(2)-50 can induce cyclohexane photooxidation in repeated cycles, but with the former the yield in cyclohexanone is higher and only traces of cyclohexanol are observed. The results of experiments with different incident light intensities are reported: contrary to mpTiO(2)-50, the selectivity of mpTiO(2)-100 towards cyclohexanone is not significantly affected by the photonic flux. Based on the substrate conversion rates, incident photonic flux effects, photoluminescence and EPR spectra of the mesoporous materials, we infer that the photoreactivity of mpTiO(2)-100 and mpTiO(2)-50 is mainly controlled by textural effects. In particular, we propose that the inter-particle electron mobility that characterizes the mpTiO(2)-100 material, which is constituted exclusively of TiO(2) nanoparticles, entails a better utilization of electron traps for converting the photogenerated cyclohexyl-peroxide radicals to cyclohexanone.
    Language English
    Publishing date 2008-07
    Publishing country England
    Document type Journal Article
    ZDB-ID 2072584-X
    ISSN 1474-9092 ; 1474-905X
    ISSN (online) 1474-9092
    ISSN 1474-905X
    DOI 10.1039/b804377a
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  7. Article: Photocatalysis with organized systems for the oxofunctionalization of hydrocarbons by O2.

    Maldotti, Andrea / Molinari, Alessandra / Amadelli, Rossano

    Chemical reviews

    2003  Volume 102, Issue 10, Page(s) 3811–3836

    Language English
    Publishing date 2003-04-01
    Publishing country United States
    Document type Journal Article
    ZDB-ID 207949-5
    ISSN 1520-6890 ; 0009-2665
    ISSN (online) 1520-6890
    ISSN 0009-2665
    DOI 10.1021/cr010364p
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 4' 49/78: Show issues
    Z 4.4: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  8. Article: Photocatalytic formation of a carbamate through ethanol-assisted carbonylation of p-nitrotoluene

    Maldotti, Andrea / Amadelli, Rossano / Samiolo, Luca / Molinari, Alessandra / Penoni, Andrea / Tollari, Stefano / Cenini, Sergio

    Chemical communications. 2005 Mar. 24, , no. 13

    2005  

    Abstract: The nitroarene p-nitrotoluene is converted with a selectivity higher than 85% to the corresponding carbamate at room temperature and atmospheric pressure, using photoexcited particles of TiO2 as catalyst and EtOH as carbonylating species. ...

    Abstract The nitroarene p-nitrotoluene is converted with a selectivity higher than 85% to the corresponding carbamate at room temperature and atmospheric pressure, using photoexcited particles of TiO2 as catalyst and EtOH as carbonylating species.
    Keywords ambient temperature ; atmospheric pressure ; catalysts ; ethanol ; photocatalysis ; titanium dioxide
    Language English
    Dates of publication 2005-0324
    Size p. 1749-1751.
    Publishing place The Royal Society of Chemistry
    Document type Article
    ZDB-ID 1472881-3
    ISSN 1364-548X ; 1359-7345 ; 0009-241X
    ISSN (online) 1364-548X
    ISSN 1359-7345 ; 0009-241X
    DOI 10.1039/b418571d
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  9. Article: Photocatalytic formation of a carbamate through ethanol-assisted carbonylation of p-nitrotoluene.

    Maldotti, Andrea / Amadelli, Rossano / Samiolo, Luca / Molinari, Alessandra / Penoni, Andrea / Tollari, Stefano / Cenini, Sergio

    Chemical communications (Cambridge, England)

    2005  , Issue 13, Page(s) 1749–1751

    Abstract: The nitroarene p-nitrotoluene is converted with a selectivity higher than 85% to the corresponding carbamate at room temperature and atmospheric pressure, using photoexcited particles of TiO2 as catalyst and EtOH as carbonylating species. ...

    Abstract The nitroarene p-nitrotoluene is converted with a selectivity higher than 85% to the corresponding carbamate at room temperature and atmospheric pressure, using photoexcited particles of TiO2 as catalyst and EtOH as carbonylating species.
    Language English
    Publishing date 2005-04-07
    Publishing country England
    Document type Journal Article
    ZDB-ID 1472881-3
    ISSN 1364-548X ; 1359-7345 ; 0009-241X
    ISSN (online) 1364-548X
    ISSN 1359-7345 ; 0009-241X
    DOI 10.1039/b418571d
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

To top