TY - CONF A1 - Marquardt, Julien T1 - Investigating the morphology of nanostructured mixed metal oxides (Ir/TiOx) and its impact on the electrocatalytic OER-activity N2 - The electrocatalytic conversion of water into molecular hydrogen and oxygen under the utilization of excess renewable energies, such as wind power, photovoltaics and hydroelectric power is one possible pathway to establish a sustainable hydrogen economy. The obtained hydrogen is either stored and used in a fuel cell or consumed on-site in industrial applications. Water electrolysis systems (WES) are based on two half cell reactions, such as oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) which both proceed simultaneously. The OER suffers from slow reaction kinetics and thus limits the overall performance. The most promising compounds in acidic electrolysis are IrO2 and RuO2. Due to their rare abundance and extremely high price a wide use of acidic WES was prevented. Lowering the catalysts noble metal content by mixing iridium with titanium reduces the production costs. Thin films are produced by dip coating a solution of metal oxide precursors alongside with a polymer template dissolved in ethanol. The obtained samples are subsequently calcined to the remove the template and adjust crystallinity. Finally, an additional iridium deposition step was performed on the outer surface plane area. Understanding the influence of structural and morphological aspects on the OER-activity is beneficial to further optimize WES. The current presentation will thus give detailed insights to structural aspects obtained by Raman spectroscopy, small- and wide-angle X-ray scattering which are then combined with electrochemical parameters to deduce structure-activity relationships. T2 - Joint Polish-German Crystallographic Meeting 2020 CY - Wrocław, Poland DA - 24.02.2020 KW - nanostructured KW - electrocatalysis PY - 2020 AN - OPUS4-50664 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Baláž, M. A1 - Tešinský, M. A1 - Marquardt, Julien A1 - Škrobian, M. A1 - Daneu, N. A1 - Rajňák, M. A1 - Baláž, P. T1 - Synthesis of copper nanoparticles from refractory sulfides using a semi-industrial mechanochemical approach N2 - The large-scale mechanochemical reduction of binary sulfides chalcocite (Cu2S) and covellite (CuS) by elemental iron was investigated in this work. The reduction of Cu2S was almost complete after 360 min of milling, whereas in the case of CuS, a significant amount of non-reacted elemental iron could still be identified after 480 min. Upon application of more effective laboratory-scale planetary ball milling, it was possible to reach almost complete reduction of CuS. Longer milling leads to the formation of ternary sulfides and oxidation product, namely cuprospinel CuFe2O4. The rate constant calculated from the magnetometry measurements using a diffusion model for Cu2S and CuS reduction by iron in a large-scale mill is 0.056 min−0.5 and 0.037 min−0.5, respectively, whereas for the CuS reduction in a laboratory-scale mill, it is 0.1477 min−1. The nanocrystalline character of the samples was confirmed by TEM and XRD, as the produced Cu exhibited sizes up to 16 nm in all cases. The process can be easily scaled up and thus copper can be obtained much easier from refractory minerals than in traditional metallurgical approaches. KW - Mechanochemistry KW - Copper sulfides KW - Copper nanoparticles KW - Magnetometry KW - Oxidation PY - 2020 DO - https://doi.org/10.1016/j.apt.2019.11.032 VL - 31 IS - 2 SP - 782 EP - 791 PB - Elsevier B.V. AN - OPUS4-50665 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Brinker, U. A1 - Bērziņš, V. A1 - Ceriņa, A. A1 - Gerhards, G. A1 - Kalniņš, M. A1 - Schmölcke, U. A1 - Meinel, Dietmar A1 - Luebke, H. T1 - Two burials in a unique freshwater shell midden: insights into transformations of Stone Age hunter-fisher daily life in Latvia N2 - The Stone Age site Riņņukalns, Latvia, is the only well-stratified shell midden in the Eastern Baltic. In this paper, we present new interdisciplinary results concerning its dating, stratigraphy, features, and finds to shed light on the daily life of a fisher population prior to the introduction of domesticated animals. The undisturbed part of the midden consists of alternating layers of unburnt mussel shell, burnt mussel shell and fish bone, containing artefacts, some mammal and bird bones, and human burials. Two of them, an adult man and a baby, are discovered recently and date to the calibration plateau between 3350 and 3100 cal BC, and to the later 4th millennium, respectively. Stable isotopes suggest a diet based heavily on freshwater fish, and this is supported not only by ten thousands of identified fish remains, but also by a fish bone concentration nearby the skull of the man, which is interpreted as remain of a grave gift (possible fish soup). Of special interest are the baby’s stable isotope values. It shows that the mother’s diet was atypical (perhaps because she was non-local), and/or that dietary stress during pregnancy increased fractionation between the mother’s diet and her bloodstream KW - Baltic Stone Age KW - Palaeoanthropology PY - 2020 DO - https://doi.org/10.1007/s12520-020-01049-7 VL - 12 IS - 5 SP - Article number: 97 PB - Springer-Verlag GmbH CY - Germany AN - OPUS4-50653 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Aratsu, K. A1 - Takeya, R. A1 - Pauw, Brian Richard A1 - Hollamby, M.J. A1 - Kitamoto, Y. A1 - Shimizu, N. A1 - Takagi, H. A1 - Haruki, R. A1 - Adachi, S. A1 - Yagai, S. T1 - Supramolecular copolymerization driven by integrative self-sorting of hydrogen-bonded rosettes N2 - Molecular recognition to preorganize noncovalently polymerizable supramolecular complexes is a characteristic process of natural supramolecular polymers, and such recognition processes allow for dynamic self-alteration, yielding complex polymer systems with extraordinarily high efficiency in their targeted function. We herein show an example of such molecular recognition-controlled kinetic assembly/disassembly processes within artificial supramolecular polymer systems using six-membered hydrogen-bonded supramolecular complexes (rosettes). Electron-rich and poor monomers are prepared that kinetically coassemble through a temperature-controlled protocol into amorphous coaggregates comprising a diverse mixture of rosettes. Over days, the electrostatic interaction between two monomers induces an integrative self-sorting of rosettes. While the electron-rich monomer inherently forms toroidal homopolymers, the additional electrostatic interaction that can also guide rosette association allows helicoidal growth of supramolecular copolymers that are comprised of an alternating array of two monomers. Upon heating, the helicoidal copolymers undergo a catastrophic transition into amorphous coaggregates via entropy-driven randomization of the monomers in the rosette. KW - Self-assembly KW - Coaggregation KW - Scattering KW - Simulation KW - AFM PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506555 DO - https://doi.org/10.1038/s41467-020-15422-6 VL - 11 IS - 1 SP - Article number: 1623 PB - Springer Nature AN - OPUS4-50655 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - INPR A1 - Tscheuschner, Georg A1 - Schwaar, Timm A1 - Weller, Michael G. T1 - Fast Confirmation of Antibody Identity by MALDI-TOF-MS Fingerprints N2 - Thousands of antibodies for diagnostic and other analytical purposes are on the market. However, it is often difficult to identify duplicates, reagent changes, and to assign the correct original publications to an antibody. This slows down scientific progress and might even be a cause of irreproducible research and a waste of resources. Recently, activities were started to suggest the sole use of recombinant antibodies in combination with the open communication of their sequence. In this case, such uncertainties should be eliminated. Unfortunately, this approach seems to be rather a long-term vision since the development and manufacturing of recombinant antibodies remain quite expensive in the foreseeable future. Also, nearly all commercial antibody suppliers may be reluctant to publish the sequence of their antibodies, since they fear counterfeiting. De-novo sequencing of antibodies is also not feasible today for a reagent user without access to the hybridoma clone. Nevertheless, it seems to be crucial for any scientist to have the opportunity to identify an antibody undoubtedly to guarantee the traceability of any research activity using antibodies from a third party as a tool. For this purpose, we developed a method for the identification of antibodies based on a MALDI-TOF-MS fingerprint. To circumvent lengthy denaturation, reduction, alkylation, and enzymatic digestion steps, the fragmentation was performed with a simple formic acid hydrolysis step. Eighty-nine unknown monoclonal antibodies were used for this study to examine the feasibility of this approach. Although the molecular assignment of peaks was rarely possible, antibodies could be easily recognized in a blinded test, simply from their mass-spectral fingerprint. A general protocol is given, which could be used without any optimization to generate fingerprints for a database. We want to propose that in most scientific projects relying critically on antibody reagents, such a fingerprint should be established to prove and document the identity of the used antibodies and to assign a specific reagent to a datasheet of a commercial supplier, a public database record or an antibody ID. KW - Reproducibility KW - Quality Control KW - Traceability KW - Diagnostics KW - ELISA KW - Immunoassay PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506590 DO - https://doi.org/10.20944/preprints202002.0207.v1 SN - 2310-287X SP - 1 EP - 17 PB - MDPI CY - Basel AN - OPUS4-50659 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sachse, René A1 - Bernsmeier, D. A1 - Schmack, R. A1 - Häusler, I. A1 - Hertwig, Andreas A1 - Kraffert, K. A1 - Nissen, J. A1 - Kraehnert, R. T1 - Colloidal bimetallic platinum–ruthenium nanoparticles in ordered mesoporous carbon films as highly active electrocatalysts for the hydrogen evolution reaction N2 - Hydrogen features a very high specific energy density and is therefore a promising candidate for clean fuel from renewable resources. Water electrolysis can convert electrical energy into storable and transportable hydrogen gas. Under acidic conditions, platinum is the most active and stable monometallic catalyst for the hydrogen evolution reaction (HER). Yet, platinum is rare and needs to be used efficiently. Here, we report a synthesis concept for colloidal bimetallic platinum–ruthenium and rhodium–ruthenium nanoparticles (PtRuNP, RhRuNP) and their incorporation into ordered mesoporous carbon (OMC) films. The films exhibit high surface area, good electrical conductivity and well-dispersed nanoparticles inside the mesopores. The nanoparticles retain their size, crystallinity and composition during carbonization. In the hydrogen evolution reaction (HER), PtRuNP/OMC catalyst films show up to five times higher activity per Pt than Pt/C/Nafion® and PtRu/C/Nafion® reference catalysts. KW - Ordered mesoporous carbon KW - Bimetallic noble metal nanoparticles KW - Platinum-ruthenium colloid KW - Electrolysis KW - Hydrogen evolution reaction PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506868 DO - https://doi.org/10.1039/C9CY02285F SN - 2044-4753 VL - 10 IS - 7 SP - 2057 EP - 2068 PB - Royal Society of Chemistry AN - OPUS4-50686 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dittmann, Daniel A1 - Eisentraut, Paul A1 - Goedecke, Caroline A1 - Wiesner, Yosri A1 - Jekel, M A1 - Ruhl, A S A1 - Braun, Ulrike T1 - Specific adsorption sites and conditions derived by thermal decomposition of activated carbons and adsorbed carbamazepine N2 - The adsorption of organic micropollutants onto activated carbon is a favourable solution for the treatment of drinking water and wastewater. However, these adsorption processes are not sufficiently understood to allow for the appropriate prediction of removal processes. In this study, thermogravimetric analysis, alongside evolved gas analysis, is proposed for the characterisation of micropollutants adsorbed on activated carbon. Varying amounts of carbamazepine were adsorbed onto three different activated carbons, which were subsequently dried, and their thermal decomposition mechanisms examined. The discovery of 55 different pyrolysis products allowed differentiations to be made between specific adsorption sites and conditions. However, the same adsorption mechanisms were found for all samples, which were enhanced by inorganic constituents and oxygen containing surface groups. Furthermore, increasing the loadings led to the evolution of more hydrated decomposition products, whilst parts of the carbamazepine molecules were also integrated into the carbon structure. It was also found that the chemical composition, especially the degree of dehydration of the activated carbon, plays an important role in the adsorption of carbamazepine. Hence, it is thought that the adsorption sites may have a higher adsorption energy for specific adsorbates, when the activated carbon can then potentially increase its degree of graphitisation. KW - Aktivkohle KW - TED-GC/MS KW - Adsorption KW - Thermoanalytik PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506946 DO - https://doi.org/10.1038/s41598-020-63481-y VL - 10 IS - 1 SP - 6695 PB - Nature Publishing Group AN - OPUS4-50694 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zimmermann, T. A1 - von der Au, Marcus A1 - Reese, A. A1 - Klein, O. A1 - Hildebrandt, L. A1 - Pröfrock, D. T1 - Substituting HF by HBF4 – an optimized digestion method for multi-elemental sediment analysis via ICP-MS/MS N2 - Determination of elemental mass fractions in sediments plays a major role in evaluating the environmental status of aquatic ecosystems. Herewith, the optimization of a new total digestion protocol and the subsequent analysis of 48 elements in different sediment reference materials (NIST SRM 2702, GBW 07313, GBW 07311 and JMC-2) based on ICP-MS/MS detection is presented. The developed method applies microwave acid digestion and utilizes HBF4 as fluoride source for silicate decomposition. Similar to established protocols based on HF, HBF4 ensures the dissolution of the silicate matrix, as well as other refractory oxides. As HBF4 is not acutely toxic; no special precautions have to be made and digests can be directly measured via ICP-MS without specific sample inlet systems, evaporation steps or the addition of e.g. H3BO3, in order to mask excess HF. Different acid mixtures with and without HBF4 were evaluated in terms of digestion efficiency based on the trace metal recovery. The optimized protocol (5 mL HNO3, 2 mL HCL, 1 mL HBF4) allows a complete dissolution of the analyzed reference materials, as well as quantitative recoveries for a wide variety of certified analytes. Low recoveries for e.g. Sr, Ba and rare earth elements due to fluoride precipitation of HF-based digestions protocols, can be avoided by the usage of HBF4 instead. Based on the usage of high purity HBF4 all relevant trace, as well as matrix elements can be analyzed with sufficiently low LOQs (0.002 μg L−1 for U up to 6.7 μg L−1 for Al). In total, 34 elements were within a recovery range of 80%–120% for all three analyzed reference materials GBW 07313, GBW 07311 and JMC-2. 14 elements were outside a recovery range of 80%–120% for at least one of the analyzed reference materials. KW - Reference Materials KW - Sediment KW - HF free Digestion PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-510480 DO - https://doi.org/10.1039/D0AY01049A SP - 1 EP - 10 PB - Royal Society of Chemistry AN - OPUS4-51048 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Raschpichler, C. A1 - Goroncy, C. A1 - Langer, B. A1 - Antonsson, E. A1 - Wassermann, B. A1 - Graf, C. A1 - Klack, Patrick A1 - Lischke, T. A1 - Rühl, E. T1 - Surface Properties and Porosity of Silica Particles Studied by Wide-Angle Soft X-ray Scattering N2 - Wide-angle soft X-ray scattering on free silica particles of different porosity prepared in a beam is reported. The explored q region is mostly dominated by features due to surface roughness and bulk porosity. A comprehensive experimental and theoretical analysis of silica particles of different porosity is presented for various incident photon energies. A correlation analysis, based on the theory of Porod, is used to test the validity of exact Mie theory in different pore density limits. The ability of the discrete dipole scattering model (DDSCAT) to resolve local effects, caused by various pore distributions, is discussed. Characteristic differences between the soft X-ray scattering patterns of the particle samples of different surface properties and porosity are detected. For all mentioned cases, it was confirmed that the effective radius concept of the Guinier model can be successfully extended to Mie theory and DDSCAT in describing the additive contributions of the primary particles, including a thin inhomogeneous solvent-rich surface shell and empty bulk pores. Close agreement, within ±15%, between the calculated and observed pore sizes and porosity values is reached. The influence of pores is alternatively described either in terms of secondary Mie scattering, which is modulated by the local internal electrical field within the particles, or by an independent Mie scattering process induced by the incident field on isolated pores. It is found that for the typical pore/particle size ratios the latter approach presents the best choice. KW - Wide-Angle Soft X‑ray Scattering KW - Silica KW - Porosity PY - 2020 DO - https://doi.org/10.1021/acs.jpcc.0c04308 SN - 1932-7447 SN - 1932-7455 VL - 124 SP - 16663 EP - 16674 AN - OPUS4-51089 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Medeiros, V.L. A1 - Goulart de Araujo, L. A1 - Ratero, D.R. A1 - Paula, A.S. A1 - Ferreira Molina, E. A1 - Jaeger, Christian A1 - Takehiro Marumo, J. T1 - Synthesis and physicochemical characterization of a novel adsorbent based on yttrium silicate: A potential material for removal of lead and cadmium from aqueous media N2 - A new metallosilicate based on yttrium was synthesized and characterized by XRD, FT-IR, 29Si MAS-NMR, and 89Y MAS-NMR. The mixed framework of the material was confirmed by the detection of distinct chemical shift groups using 29Si MAS-NMR (at -82 to -87 ppm, -91 to -94 ppm, -96 to -102 ppm, and -105 to -108 ppm), as well as four distinct chemical shifts in the 89Y MAS-NMR spectrum (at -89, -142, -160, and -220 ppm). Adsorption and kinetic analyses indicated the potential of the new material for the removal of lead and cadmium from aqueous media. The adsorption results for lead indicated that dynamic equilibrium was reached after five hours, with total lead removal of around 94 %, while for cadmium it was reached in the first hour, with total Cadmium removal of around 74 %. The adsorptions of lead and cadmium were modeled using pseudo-first order (PFO) and pseudo-second order (PSO) kinetic models. Although both models provided high R2 values (0.9903 and 0.9980, respectively), the PSO model presented a much lower χ2 red value (4.41×10−4), compared to the PFO model (2.12×10−3), which indicated that the rate-limiting step was probably due to the chemisorption of lead from the solution onto the yttrium-based metallosilicate. KW - Yttrium silicates KW - 29Si KW - 89Y MAS-NMR KW - Adsorption KW - Chemisorption KW - Cadmium and lead remediation PY - 2020 DO - https://doi.org/10.1016/j.jece.2020.103922 VL - 8 SP - 103922 PB - Elsevier Ltd. AN - OPUS4-51292 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -