Using a dual plasma process to produce cobalt--polypyrrole catalysts for the oxygen reduction reaction in fuel cells -- part II: analysing the chemical structure of the films

The chemical structure of cobalt--polypyrrole -- produced by a dual plasma process -- is analysed by means of X-ray photoelectron spectroscopy (XPS), near edge X-ray absorption spectroscopy (NEXAFS), X-ray diffraction (XRD), energy-dispersive X-Ray spectroscopy (EDX) and extended x-ray absorption spectroscopy (EXAFS).It is shown that only nanoparticles of a size of 3\,nm with the low temperature crystal structure of cobalt are present within the compound. Besides that, cobalt--nitrogen and carbon--oxygen structures are observed. Furthermore, more and more cobalt--nitrogen structures are produced when increasing the magnetron power. Linking the information on the chemical structure to the results about the catalytic activity of the films -- which are presented in part I of this contribution -- it is concluded that the cobalt--nitrogen structures are the probable catalytically active sites. The cobalt--nitrogen bond length is calculated as 2.09\,\AA\ and the carbon--nitrogen bond length as 1.38\,\AA

Teilvorhaben: "Plasmachemische Oberflächenbehandlung von Grafitfasern in einer Niederdruck-Wirbelschicht" des Verbundprojekts: "Grundlegende Untersuchungen zur plasmachemischen Behandlung von Grafitfasern für innovative Einsatzpotentiale" : Schlussbericht

[no abstract available

Morphology, Optical Properties and Photocatalytic Activity of Photo- and Plasma-Deposited Au and Au/Ag Core/Shell Nanoparticles on Titania Layers

Titania is a promising material for numerous photocatalytic reactions such as water splitting and the degradation of organic compounds (e.g., methanol, phenol). Its catalytic performance can be significantly increased by the addition of co-catalysts. In this study, Au and Au/Ag nanoparticles were deposited onto mesoporous titania thin films using photo-deposition (Au) and magnetron-sputtering (Au and Au/Ag). All samples underwent comprehensive structural characterization by grazing incidence X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Nanoparticle distributions and nanoparticle size distributions were correlated to the deposition methods. Light absorption measurements showed features related to diffuse scattering, the band gap of titania and the local surface plasmon resonance of the noble metal nanoparticles. Further, the photocatalytic activities were measured using methanol as a hole scavenger. All nanoparticle-decorated thin films showed significant performance increases in hydrogen evolution under UV illumination compared to pure titania, with an evolution rate of up to 372 μL H2 h−1 cm−2 representing a promising approximately 12-fold increase compared to pure titania

Degradation of glyphosate in water by the application of surface corona discharges

Glyphosate (GLP) is one of the most widely applied herbicides, and is found ubiquitously in the environment. The removal of glyphosate from waste water and soil is challenging and can be achieved with chemical or biological methods, which, nevertheless, suffer from different disadvantages. The application of a physical plasma for the removal of GLP in water was examined by the application of surface corona discharges in a wire-to-cylinder setup filled with argon. The plasma was ignited at the liquid surface without any additives. By applying a photometric method, GLP was detected after derivatisation with fluorenyl methoxycarbonyl chloride, whereas phosphate was determined with ammonium molybdate. A GLP degradation rate of 90.8% could be achieved within a treatment time of 30 minutes with an estimated energy efficiency of 0.32 g/kWh

Plasma‐Assisted Immobilization of a Phosphonium Salt and Its Use as a Catalyst in the Valorization of CO2

The first plasma‐assisted immobilization of an organocatalyst, namely a bifunctional phosphonium salt in an amorphous hydrogenated carbon coating, is reported. This method makes the requirement for prefunctionalized supports redundant. The immobilized catalyst was characterized by solid‐state 13C and 31P NMR spectroscopy, SEM, and energy‐dispersive X‐ray spectroscopy. The immobilized catalyst (1 mol %) was employed in the synthesis of cyclic carbonates from epoxides and CO2. Notably, the efficiency of the plasma‐treated catalyst on SiO2 was higher than those of the SiO2 support impregnated with the catalyst and even the homogeneous counterpart. After optimization of the reaction conditions, 13 terminal and four internal epoxides were converted with CO2 to the respective cyclic carbonates in yields of up to 99 %. Furthermore, the possibility to recycle the immobilized catalyst was evaluated. Even though the catalyst could be reused, the yields gradually decreased from the third run. However, this is the first example of the recycling of a plasma‐immobilized catalyst, which opens new possibilities in the recovery and reuse of catalysts

Environmental applications of plasma technology

Энергосбережение, энергоэффективные технологии и энергетический менеджмент, возобновляемые источники энерги

Chemical-reagent free in-situ phosphat sensor based on innovative opto-electrochemical principles : CaliPSo ; Abschlussbericht ; Teilprojekt INP und Unterauftrag AMT ; Berichtszeitraum: 01.10.2008 bis 31.01.2012

[no abstract available

Verbundprojekt: Spitzenforschung und Innovation in den Neuen Ländern - Light2Hydrogen - "Energie für die Zukunft - Photokatalytische Spaltung von Wasser zu Wasserstoff": TP 2; TP 3 : Schlussbericht

[no abstract available

Применения плазменной технологии синтеза и медицинского машиностроения наноструктурного материала / Фолькер Брюзер, Сандра Пеглоу, Томас фон Вёдтке

Энергосбережение, энергоэффективные технологии и энергетический менеджмент, возобновляемые источники энергииTwo topics will be presented in this presentation: nanostructured material synthesis and medical engeneering. Both low pressure and atmospheric pressure plasmas are used in these applications.Для рассмотрения представлены две темы: синтез наноструктурированных материалов и медикаментозное проектирование. При их применении используются как плазма низкого давления, так и атмосферное давление