TY - JOUR A1 - Westwood, S. A1 - Martos, G. A1 - Josephs, R. A1 - Choteau, T. A1 - Wielgosz, R. A1 - Davies, S. A1 - Moawad, M. A1 - Tarrant, G. A1 - Chan, B. A1 - Alamgir, M. A1 - de Rego, E. A1 - Wollinger, W. A1 - Garrido, B. A1 - Fernandes, J. A1 - de Sena, R. A1 - Oliveira, R. A1 - Melanson, J. A1 - Bates, J. A1 - Mai Le, P. A1 - Meija, J. A1 - Quan, C. A1 - Huang, T. A1 - Zhang, W. A1 - Ma, R. A1 - Zhang, S. A1 - Hao, Y. A1 - He, Y. A1 - Song, S. A1 - Wang, H. A1 - Su, F. A1 - Zhang, T. A1 - Li, H. A1 - Lam, W. A1 - Wong, W. A1 - Fung, W. A1 - Philipp, Rosemarie A1 - Dorgerloh, Ute A1 - Meyer, Klas A1 - Piechotta, Christian A1 - Riedel, Juliane A1 - Westphalen, Tanja A1 - Giannikopoulou, P. A1 - Alexopoulos, Ch. A1 - Kakoulides, E. A1 - Kitamaki, Y. A1 - Yamazaki, T. A1 - Shimizu, Y. A1 - Kuroe, M. A1 - Numata, M. A1 - Pérez-Castorena, A. A1 - Balderas-Escamilla, M. A1 - Garcia-Escalante, J. A1 - Krylov, A. A1 - Mikheeva, A. A1 - Beliakov, M. A1 - Palagina, M. A1 - Tkachenko, I. A1 - Spirin, S. A1 - Smirnov, V. A1 - Tang Lin, T. A1 - Pui Sze, C. A1 - Juan, W. A1 - Lingkai, W. A1 - Ting, L. A1 - Quinde, L. A1 - Yizhao, C. A1 - Lay Peng, S. A1 - Fernandes-Whaley, M. A1 - Prevoo-Franzsen, D. A1 - Quinn, L. A1 - Nhlapo, N. A1 - Mkhize, D. A1 - Marajh, D. A1 - Chamane, S. A1 - Ahn, S. A1 - Choi, K. A1 - Lee, S. A1 - Han, J. A1 - Baek, S. A1 - Kim, B. A1 - Marbumrung, S. A1 - Jongmesuk, P. A1 - Shearman, K. A1 - Boonyakong, C. A1 - Bilsel, M. A1 - Gündüz, S. A1 - Ün, I. A1 - Yilmaz, H. A1 - Bilsel, G. A1 - Gökçen, T. A1 - Clarkson, C. A1 - Warren, J. A1 - Achtar, E. T1 - Mass fraction assignment of Bisphenol-A high purity material N2 - The CCQM-K148.a comparison was coordinated by the BIPM on behalf of the CCQM Organic Analysis Working Group for NMIs and DIs which provide measurement services in organic analysis under the CIPM MRA. It was undertaken as a "Track A" comparison within the OAWG strategic plan. CCQM-K148.a demonstrates capabilities for assigning the mass fraction content of a solid organic compound having moderate molecular complexity, where the compound has a molar mass in the range (75 - 500) g/mol and is non-polar (pKow < −2), when present as the primary organic component in a neat organic solid and where the mass fraction content of the primary component in the material is in excess of 950 mg/g. Participants were required to report the mass fraction of Bisphenol A present in one supplied unit of the comparison material. Participants using a mass balance method for the assignment were also required to report their assignments of the impurity components present in the material. Methods used by the seventeen participating NMIs or DIs were predominantly based on either stand-alone mass balance (summation of impurities) or qNMR approaches, or the combination of data obtained using both methods. The results obtained using thermal methods based on freezing-point depression methods were also reported by a limited number of participants. There was excellent agreement between assignments obtained using all three approaches to assign the BPA content. The assignment of the values for the mass fraction content of BPA consistent with the KCRV was achieved by most of the comparison participants with an associated relative standard uncertainty in the assigned value in the range (0.1 - 0.5)%. KW - Bisphenol-A KW - Purity assessment KW - Interlaboratory key comparison KW - Metrology PY - 2021 DO - https://doi.org/10.1088/0026-1394/58/1A/08015 VL - 58 IS - 1A SP - 08015 PB - IOP Publishing AN - OPUS4-54188 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Abou-Ras, D. A1 - Caballero, R. A1 - Fischer, C.-H. A1 - Kaufmann, C.A. A1 - Lauermann, I. A1 - Mainz, R. A1 - Mönig, H. A1 - Schöpke, A. A1 - Stephan, C. A1 - Streeck, C. A1 - Schorr, S. A1 - Eicke, A. A1 - Döbeli, M. A1 - Gade, B. A1 - Hinrichs, J. A1 - Nunney, T. A1 - Dijkstra, H. A1 - Hoffmann, V. A1 - Klemm, D. A1 - Efimova, V. A1 - Bergmaier, A. A1 - Dollinger, G. A1 - Wirth, Thomas A1 - Unger, Wolfgang A1 - Rockett, A.A. A1 - Perez-Rodriguez, A. A1 - Alvarez-Garcia, J. A1 - Izquierdo-Roca, V. A1 - Schmid, T. A1 - Choi, P.-P. A1 - Müller, M. A1 - Bertram, F. A1 - Christen, J. A1 - Khatri, H. A1 - Collins, R.W. A1 - Marsillac, S. A1 - Kötschau, I. T1 - Comprehensive comparison of various techniques for the analysis of elemental distributions in thin films N2 - The present work shows results on elemental distribution analyses in Cu(In,Ga)Se2 thin films for solar cells performed by use of wavelength-dispersive and energy-dispersive X-ray spectrometry (EDX) in a scanning electron microscope, EDX in a transmission electron microscope, X-ray photoelectron, angle-dependent soft X-ray emission, secondary ion-mass (SIMS), time-of-flight SIMS, sputtered neutral mass, glow-discharge optical emission and glow-discharge mass, Auger electron, and Rutherford backscattering spectrometry, by use of scanning Auger electron microscopy, Raman depth profiling, and Raman mapping, as well as by use of elastic recoil detection analysis, grazing-incidence X-ray and electron backscatter diffraction, and grazing-incidence X-ray fluorescence analysis. The Cu(In,Ga)Se2 thin films used for the present comparison were produced during the same identical deposition run and exhibit thicknesses of about 2 µm. The analysis techniques were compared with respect to their spatial and depth resolutions, measuring speeds, availabilities, and detection limits. KW - Elemental distributions KW - Comparison KW - Depth profiling KW - Chemical mapping KW - Thin films KW - Solar cells KW - Chalcopyrite-type KW - Cu(In,Ga)Se2 PY - 2011 DO - https://doi.org/10.1017/S1431927611000523 SN - 1431-9276 SN - 1435-8115 VL - 17 IS - 5 SP - 728 EP - 751 PB - Cambridge University Press CY - New York, NY AN - OPUS4-24506 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Climent Terol, Estela A1 - Mondragón, L. A1 - Martínez-Mánez, Ramon A1 - Sancenón, F. A1 - Marcos, M. Dolores A1 - Murguía, J.R. A1 - Amorós, P. A1 - Rurack, Knut A1 - Pérez-Payá, E. T1 - Selektiver, hoch empfindlicher und schneller Nachweis genomischer DNA mit gesteuerten Materialien am Beispiel von Mycoplasma N2 - Mit DNA verschlossene und mit Farbstoff beladene mesoporöse Siliciumdioxid-Nanopartikel wurden zum Nachweis von Mycoplasma bis zu einer Nachweisgrenze von ca. 70 genomischen DNA-Kopien pro µL in real kontaminierten Zellkulturmedien ohne die Hilfe von PCR-Techniken eingesetzt. KW - DNA KW - Gesteuerte Materialien KW - Mesoporöse Träger KW - Mycoplasma KW - Sonden PY - 2013 DO - https://doi.org/10.1002/ange.201302954 SN - 0044-8249 SN - 0932-2140 SN - 1521-3757 VL - 125 IS - 34 SP - 9106 EP - 9110 PB - Wiley-VCH CY - Weinheim AN - OPUS4-28970 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Climent Terol, Estela A1 - Mondragón, L. A1 - Martínez-Mánez, Ramon A1 - Sancenón, F. A1 - Marcos, M. Dolores A1 - Murguía, J.R. A1 - Amorós, P. A1 - Rurack, Knut A1 - Pérez-Payá, E. T1 - Selective, highly sensitive, and rapid detection of genomic DNA by using gated materials: Mycoplasma detection N2 - Come and gate it: DNA-capped mesoporous silica nanoparticles loaded with a dye are used to detect the common contaminate Mycoplasma in real contaminated cell-culture media without needing polymerase chain reaction (PCR) techniques, at a detection limit in the range of 70 DNA genome copies µL-1. KW - DNA KW - Gated materials KW - Mesoporous materials KW - Mycoplasma KW - Sensors PY - 2013 DO - https://doi.org/10.1002/anie.201302954 SN - 1433-7851 SN - 1521-3773 SN - 0570-0833 VL - 52 IS - 34 SP - 8938 EP - 8942 PB - Wiley-VCH CY - Weinheim AN - OPUS4-28976 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pérez, P. A1 - Cabeza, Sandra A1 - Garcés, G. A1 - Adeva, Paloma T1 - Influence of long period stacking ordered phase arrangements on thecorrosion behaviour of extruded Mg97Y2Zn1 alloy N2 - The influence of second phase arrangements on the corrosion resistance of extruded Mg97Y2Zn1 alloy has been evaluated in a 0.1 M NaCl solution. The microstructure of the alloy consists of a high volume fraction of coarse elongated particles of a long period stacking ordered phase aligned along the extrusion direction. Corrosion rate of transversal sections is lower than that of longitudinal sections. Such difference is attributed to the different orientation of second phases in longitudinal and transversal sections. The corrosion front advances mainly perpendicular to the surface in transversal samples while perpendicular and lateral growth occur in longitudinal samples KW - passive films KW - Magnesium alloys KW - anodic dissolution PY - 2016 DO - https://doi.org/10.1016/j.corsci.2016.02.024 SN - 0010-938X VL - 107 SP - 107 EP - 112 PB - Elsevier Ltd. CY - Oxford, UK AN - OPUS4-36358 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Garcés, G. A1 - Perez, P. A1 - Cabeza, Sandra A1 - Lin, H.K. A1 - Kim, S. A1 - Gan, W. A1 - Adeva, Paloma T1 - Reverse tension /compression asymmetry of a Mg–Y–Zn alloys N2 - Room temperature mechanical behavior of extruded Mg–Y–Zn alloys with varying fractions of LPSO phase was studied in tension and compression along the extrusion direction. The microstructure is characterized by elongated LPSO fibers along the extrusion direction within the magnesium matrix. Moreover, the magnesium matrix presents a bimodal grain structure with dynamically-recrystallized grains and deformed, elongated grains with the basal plane parallel to the extrusion direction. The beginning of plasticity depends on the volume fraction of deformed and DRX grains. Alloys with low volume fraction of LPSO phase(o10vol%),with a high volume fraction of deformed grains, show the typical behavior of extruded magnesium alloys where yield stress in tension is higher than in compression. This effect is, however, reversed as the volume fraction of the LPSO phase increases since DRX grains are majority. KW - plasticity KW - Magnesium alloy KW - LPSO PY - 2015 DO - https://doi.org/doi:10.1016/j.msea.2015.09.003 VL - 647 SP - 287 EP - 293 PB - Elsevier B.V. CY - Amsterdam, Netherlands AN - OPUS4-36359 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Westwood, S. A1 - Josephs, R. A1 - Daireaux, A. A1 - Wielgosz, R. A1 - Davies, S. A1 - Kang, M. A1 - Ting, H. A1 - Philipp, Rosemarie A1 - Malz, Frank A1 - Shimizu, Y. A1 - Frias, E. A1 - Pérez, M. A1 - Apps, P. A1 - Fernandes-Whaley, M. A1 - De Vos, B. A1 - Wiagnon, K. A1 - Ruangrittinon, N. A1 - Wood, S. A1 - Duewer, D.L. A1 - Schantz, M.M. A1 - Bedner, M. A1 - Hancock, D. A1 - Esker, J. T1 - An international comparison of mass fraction purity assignment of theophylline: CCQM pilot study CCQM-P20.e (Theophylline) PY - 2009 DO - https://doi.org/10.1088/0026-1394/46/1A/08019 SN - 0026-1394 SN - 1681-7575 VL - 46 IS - 08019 SP - 1 EP - 37 PB - Inst. of Physics Publ. CY - Bristol AN - OPUS4-20030 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cabeza, Sandra A1 - Garcés, G. A1 - Pérez, P. A1 - Adeva, Paloma T1 - Properties of WZ21 (%wt) alloy processed by a powder metallurgy route N2 - Microstructure, mechanical properties and corrosion behaviour of WZ21 (%wt.) alloy prepared by a powder metallurgy route from rapidly solidified powders have been studied. Results were compared to those of the same alloy prepared through a conventional route of casting and extrusion. The microstructure of the extruded ingot consisted of α-Mg grains and Mg3Zn3Y2 (W-phase) and LPSO-phase particles located at grain boundaries. Moreover, stacking faults were also observed within α-Mg grains. The alloy processed by the powder metallurgy route exhibited a more homogeneous and finer microstructure, with a grain size of 2 µm. In this case W-phase and Mg24Y5 phase were identified, but not the LPSO-phase. The microstructural refinement induced by the use of rapidly solidified powders strengthened the alloy at room temperature and promoted superplasticity at higher strain rates. Corrosion behaviour in PBS medium evidenced certain physical barrier effect of the almost continuous arrangements of second phases aligned along the extrusion direction in conventionally processed WZ21 alloy, with a stable tendency around 7 mm/year. On the other hand, powder metallurgy processing promoted significant pitting corrosion, inducing accelerated corrosion rate during prolonged immersion times. KW - Magnesium KW - RE KW - Microstructure KW - Creep KW - Corrosion PY - 2015 DO - https://doi.org/10.1016/j.jmbbm.2015.02.022 SN - 1751-6161 SN - 1878-0180 VL - 46 SP - 115 EP - 126 PB - Elsevier Ltd. CY - Amsterdam [u.a.] AN - OPUS4-32704 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Álvarez-García, J. A1 - Izquierdo-Roca, V. A1 - Pistor, P. A1 - Schmid, Thomas A1 - Pérez-Rodríguez, A. ED - Abou-Ras, D. ED - Kirchartz, T. ED - Rau, U. T1 - Raman spectroscopy on thin films for solar cells N2 - In the present chapter, the capabilities of Raman spectroscopy for the advanced characterisation of thin films for solar cells are reviewed. Raman spectroscopy is an optical, nondestructive technique based on the inelastic scattering of photons with elemental vibrational excitations in the material. The line shape and position of the Raman bands are determined by the crystalline structure and chemical composition of the measured samples, being sensitive to the presence of crystalline defects, impurities and strain. Presence of peaks characteristic of different phases also allows for the identification of secondary phases that are strongly related to the growth and process conditions of the films. All these aspects account for a strong interest in the analysis of the Raman spectra, providing a powerful nondestructive analytical tool for the structural and chemical assessment of the films. In addition, the combination of a Raman spectrometer with an optical microscope also allows for achieving a high spatial resolutions (of below 1 µm) when mapping surfaces and analyzing depth-resolved phase distributions in thin films. The present chapter is divided into four main sections: The two first ones are devoted to a revision of the Fundamentals of Raman spectroscopy (Section 17.2) and Vibrational modes in crystalline materials (Section 17.3). Section 17.4 deals with the main experimental considerations involved in the design and implementation of a Raman scattering setup. This is followed by a detailed description of the application of Raman scattering for the structural and chemico-physical analysis of thin film photovoltaic materials (Section 17.5), with the identification of crystalline structure and secondary phases, evaluation of film crystallinity, analysis of chemical composition of semiconductor alloys, characterisation of nanocrystalline and amorphous layers, stress effects and crystal orientations. This includes the description of corresponding state of the art and recent case examples that illustrate the capabilities of the Raman technique for the advanced characterisation of layers and process monitoring in thin-film photovoltaic technologies. KW - Thin-film solar cells KW - Polycrystalline materials KW - Raman spectroscopy KW - Raman microscopy PY - 2016 UR - http://eu.wiley.com/WileyCDA/WileyTitle/productCd-3527339922.html SN - 978-3-527-33992-1 SP - 469 EP - 499 PB - Wiley & Sons, Ltd. CY - Oxford, UK AN - OPUS4-37451 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Garces, G. A1 - Perez, P. A1 - Cabeza, Sandra A1 - Lin, H. K. A1 - Kim, S. A1 - Gan, W. A1 - Adeva, Paloma T1 - Reverse tension/compression asymmetry of a Mg-Y-Zn alloys containing LPSO phases N2 - Room temperature mechanical behavior of extruded Mg–Y–Zn alloys with varying fractions of LPSO phase was studied in tension and compression along the extrusion direction. The microstructure is characterised by elongated LPSO fibers along the extrusion direction within the magnesium matrix. Moreover, the magnesium matrix presents a bimodal grain structure with dynamically-recrystallized grains and deformed, elongated grains with the basal plane parallel to the extrusion direction. The beginning of plasticity depends on the volume fraction of deformed and DRX grains. Alloys with low volume fraction of LPSO phase (<10 vol%), with a high volume fraction of deformed grains, show the typical behavior of extruded magnesium alloys where yield stress in tension is higher than in compression. This effect is, however, reversed as the volume fraction of the LPSO phase increases since DRX grains are majority. PY - 2015 DO - https://doi.org/10.1016/j.msea.2015.09.003 SN - 0921-5093 SN - 1873-4936 VL - 647 SP - 287 EP - 293 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-35175 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kepsutlu, B. A1 - Wycisk, V. A1 - Achazi, K. A1 - Kapishnikov, S. A1 - Perez-Berna, A.J. A1 - Guttmann, P. A1 - Cossmer, Antje A1 - Pereiro, E. A1 - Ewers, H. A1 - Ballauff, M. A1 - Schneider, G. A1 - McNally, J.G. T1 - Cells Undergo Major Changes in the Quantity of Cytoplasmic Organelles after Uptake of Gold Nanoparticles with Biologically Relevant Surface Coatings N2 - Here, we use cryo soft X-ray tomography (cryo-SXT), which delivers 3D ultrastructural volumes of intact cells without chemical fixation or staining, to gain insight about nanoparticle uptake for nanomedicine. We initially used dendritic polyglycerol sulfate (dPGS) with potential diagnostic and therapeutic applications in inflammation. Although dPGS-coated gold nanoparticle (dPGS-AuNP) uptake followed a conventional endocytic/degradative pathway in human lung epithelial cell lines (A549), with cryo-SXT, we detected ∼5% of dPGS-AuNPs in the cytoplasm, a level undetectable by confocal light microscopy. We also observed ∼5% of dPGS-AuNPs in a rarely identified subcellular site, namely, lipid droplets, which are important for cellular energy metabolism. Finally, we also found substantial changes in the quantity of cytoplasmic organelles upon dPGS-AuNP uptake over the 1–6 h incubation period; the number of small vesicles and mitochondria significantly increased, and the number of multivesicular bodies and the number and volume of lipid droplets significantly decreased. Although nearly all organelle numbers at 6 h were still significantly different from controls, most appeared to be returning to normal levels. To test for generality, we also examined cells after uptake of gold nanoparticles coated with a different agent, polyethylenimine (PEI), used for nucleic acid delivery. PEI nanoparticles did not enter lipid droplets, but they induced similar, albeit less pronounced, changes in the quantity of cytoplasmic organelles. We confirmed these changes in organelle quantities for both nanoparticle coatings by confocal fluorescence microscopy. We suggest this cytoplasmic remodeling could reflect a more common cellular response to coated gold nanoparticle uptake. KW - Cellular trafficking KW - Confocal laser scanning microscopy KW - Cytoplasmic remodeling KW - Dendritic polyglycerol sulfate KW - Polyethylenimine KW - 3D ultrastructural analysis KW - Cryo-soft X-ray tomography PY - 2020 DO - https://doi.org/10.1021/acsnano.9b09264 VL - 14 IS - 2 SP - 2248 EP - 2264 AN - OPUS4-50464 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pérez Blanes, H. A1 - Ghiasi, P. A1 - Sandkühler, J. A1 - Yesilcicek, Yasemin A1 - Pentzien, Simone A1 - Conradi, Andrea A1 - Prinz, Carsten A1 - Al-Sabbagh, Dominik A1 - Thünemann, Andreas A1 - Ozcan, Ozlem A1 - Witt, Julia T1 - High CO2 reduction activity on AlCrCoCuFeNi multi-principal element alloy nanoparticle electrocatalysts prepared by means of pulsed laser ablation N2 - Noble metal-free nanoparticles (NPs) based on multi-principal element alloys (MPEAs) were synthesized using a one-step pulsed laser ablation in liquids (PLALs) method for the electrochemical reduction of CO2. Laser ablation was performed in pure water or poly-(diallyldimethylammonium chloride) (PDADMAC)-containing an aqueous solution of Al8Cr17Co17Cu8Fe17Ni33 MPEA targets. Transmission electron microscopy (TEM) measurements combined with energy dispersive X-ray (EDX) mapping were used to characterize the structure and composition of the laser-generated MPEA nanoparticles (MPEA-NPs). These results confirmed the presence of a characteristic elemental distribution of a core-shell phase structure as the predominant NP species. The electrocatalytic performance of the laser-generated MPEA-NPs was characterized by linear sweep voltammetry (LSV) demonstrating an enhanced electrocatalytic CO2 activity for PDADMAC-stabilized NPs. The findings of these investigations indicate that MPEAs have great potential to replace conventional, expensive noble metal electrocatalysts. KW - Multi-principal element alloys KW - Chemically Complex Materials KW - CCMat KW - Electrocatalysis KW - Carbon dioxide reduction KW - Pulsed laser ablation PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594018 DO - https://doi.org/10.1016/j.jmrt.2023.05.143 VL - 24 SP - 9434 EP - 9440 PB - Elsevier BV AN - OPUS4-59401 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Paskin, A. A1 - Couasnon, T. A1 - Perez, J. P. H. A1 - Lobanov, S. S. A1 - Blukis, R. A1 - Reinsch, Stefan A1 - Benning, L. G. T1 - Nucleation and Crystallization of Ferrous Phosphate Hydrate via an Amorphous Intermediate N2 - The fundamental processes of nucleation and crystallization are widely observed in systems relevant to material synthesis and biomineralization; yet most often, their mechanism remains unclear. In this study, we unravel the discrete stages of nucleation and crystallization of Fe3(PO4)2·8H2O (vivianite). We experimentally monitored the formation and transformation from ions to solid products by employing correlated, time-resolved in situ and ex situ approaches. We show that vivianite crystallization occurs in distinct stages via a transient amorphous precursor phase. The metastable amorphous ferrous phosphate (AFEP) intermediate could be isolated and stabilized. We resolved the differences in bonding environments, structure, and symmetric changes of the Fe site during the transformation of AFEP to crystalline vivianite through synchrotron X-ray absorption spectroscopy at the Fe K-edge. This intermediate AFEP phase has a lower water content and less distorted local symmetry, compared to the crystalline end product vivianite. Our combined results indicate that a nonclassical, hydration-induced nucleation and transformation driven by the incorporation and rearrangement of water molecules and ions (Fe2+ and PO4 3−) within the AFEP is the dominating mechanism of vivianite formation at moderately high to low vivianite supersaturations (saturation index ≤ 10.19). We offer fundamental insights into the aqueous, amorphous-to-crystalline transformations in the Fe2+−PO4 system and highlight the different attributes of the AFEP, compared to its crystalline counterpart. KW - Nucleation KW - Crystallization KW - Vivianite KW - Ferrous phosphate hydrate PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-580696 DO - https://doi.org/10.1021/jacs.3c01494 SN - 0002-7863 VL - 145 IS - 28 SP - 15137 EP - 15151 PB - ACS Publications AN - OPUS4-58069 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Füllenbach, L.C. A1 - Perez, J. P. H. A1 - Freeman, H.M. A1 - Thomas, A.N. A1 - Mayanna, S. A1 - Parker, J. E. A1 - Göttlicher, J. A1 - Steininger, R. A1 - Radnik, Jörg A1 - Benning, L.G. A1 - Oelkers, E.H. T1 - Nanoanalytical Identification of Siderite Dissolution-Coupled Pb Removal Mechanisms from Oxic and Anoxic Aqueous Solutions N2 - Lead(II) is a toxic pollutant often found in metalcontaminated soils and wastewaters. In acidic aqueous environments, Pb(II) is highly mobile. Chemical treatment strategies of such systems therefore often include neutralization agents and metal sorbents. Since metal solubility and the retention potential of sorbents depend on the redox state of the aqueous system, we tested the efficiency of the naturally occurring redox-sensitive ferrous iron carbonate mineral siderite to remove Pb(II) from acidic aqueous solutions in batch experiments under oxic and anoxic conditions over a total of 1008 h. Siderite dissolution led to an increase in reactive solution pH from 3 to 5.3 and 6.9, while 90 and 100% of the initial aqueous Pb(II) (0.48 × 10−3 mol kg−1) were removed from the oxic and anoxic systems, respectively. Scanning and transmission electron microscopy, combined with X-ray absorption and photoelectron spectroscopy, indicated that under oxic conditions, Pb(II) was consumed by cerussite precipitation and inner-sphere surface complexation to secondary goethite. Under anoxic conditions, Pb(II) was removed by the rapid precipitation of cerussite. This efficient siderite dissolution-coupled sequestration of Pb(II) into more stable solid phases demonstrates this potential method for contaminated water Treatment regardless of the redox environment. KW - Siderite KW - X-ray absorption spectroscopy KW - X-ray photoelectron spectroscopy KW - Wastewater treatment PY - 2020 DO - https://doi.org/10.1021/acsearthspacechem.0c00180 VL - 4 IS - 11 SP - 1966 EP - 1977 PB - ACS Publication AN - OPUS4-51961 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chen, Z. A1 - Perez, J. P. H. A1 - Smales, Glen Jacob A1 - Blukis, R. A1 - Pauw, Brian Richard A1 - Stammeier, J. A. A1 - Radnik, Jörg A1 - Smith, A. J. A1 - Benning, L. G. T1 - Impact of organic phosphates on the structure and composition of short-range ordered iron nanophases N2 - Organic phosphates (OP) are important nutrient components for living cells in natural environments, where they readily interact with ubiquitous iron phases such as hydrous ferric oxide, ferrihydrite (FHY). FHY partakes in many key bio(geo)chemical reactions including iron-mediated carbon storage in soils, or iron-storage in living organisms. However, it is still unknown how OP affects the formation, structure and properties of FHY. Here, we document how β-glycerophosphate (GP), a model OP ligand, affects the structure and properties of GP–FHY nanoparticles synthesized by coprecipitation at variable nominal molar P/Fe ratios (0.01 to 0.5). All GP–FHY precipitates were characterized by a maximum solid P/Fe ratio of 0.22, irrespective of the nominal P/Fe ratio. With increasing nominal P/Fe ratio, the specific surface area of the GP–FHY precipitates decreased sharply from 290 to 3 m2 g−1, accompanied by the collapse of their pore structure. The Fe–P local bonding environment gradually transitioned from a bidentate binuclear geometry at low P/Fe ratios to monodentate mononuclear geometry at high P/Fe ratios. This transition was accompanied by a decrease in coordination number of edge-sharing Fe polyhedra, and the loss of the corner-sharing Fe polyhedra. We show that Fe(III) polymerization is impeded by GP, and that the GP–FHY structure is highly dependent on the P/Fe ratio. We discuss the role that natural OP-bearing Fe(III) nanophases have in biogeochemical reactions between Fe–P and C species in aquatic systems. KW - Organic phosphates KW - Iron nanophases KW - Scattering KW - Diffraction KW - Nanomaterials KW - Coprecipitation KW - Carbon storage PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599399 DO - https://doi.org/10.1039/d3na01045g SN - 2516-0230 SP - 1 EP - 13 PB - Royal Society of Chemistry (RSC) CY - Cambridge AN - OPUS4-59939 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - C. Pardo Pérez, L. A1 - Arndt, A. A1 - Stojkovikj, S. A1 - Y. Ahmet, I. A1 - T. Arens,, J. A1 - Dattila, F. A1 - Wendt, R. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Davies, V. A1 - Höflich, K. A1 - Köhnen, E. A1 - Tockhorn, P. A1 - Golnak, R. A1 - Xiao, J. A1 - Schuck, G. A1 - Wollgarten, M. A1 - López, N. A1 - T. Mayer, M. T1 - Determining Structure-Activity Relationships in Oxide Derived CuSn Catalysts During CO2 Electroreduction Using X-Ray Spectroscopy N2 - The development of earth-abundant catalysts for selective electrochemical CO2 conversion is a central challenge. Cu-Sn bimetallic catalysts can yield selective CO2 reduction toward either CO or formate. This study presents oxide-derived Cu-Sn catalysts tunable for either product and seeks to understand the synergetic effects between Cu and Sn causing these selectivity trends. The materials undergo significant transformations under CO2 reduction conditions, and their dynamic bulk and surface structures are revealed by correlating observations from multiple methods—X-ray absorption spectroscopy for in situ study, and quasi in situ X-ray photoelectron spectroscopy for surface sensitivity. For both types of catalysts, Cu transforms to metallic Cu0 under reaction conditions. However, the Sn speciation and content differ significantly between the catalyst types: the CO-selective catalysts exhibit a surface Sn content of 13 at. % predominantly present as oxidized Sn, while the formate-selective catalysts display an Sn content of ≈70 at. % consisting of both metallic Sn0 and Sn oxide species. Density functional theory simulations suggest that Snδ+ sites weaken CO adsorption, thereby enhancing CO selectivity, while Sn0 sites hinder H adsorption and promote formate production. This study reveals the complex dependence of catalyst structure, composition, and speciation with electrochemical bias in bimetallic Cu catalysts. KW - Electrochemical CO2 conversion KW - Cu catalysts KW - X-ray absorption spectroscopy PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-547116 DO - https://doi.org/10.1002/aenm.202103328 SN - 1614-6832 VL - 12 IS - 5 SP - 2103328 PB - Wiley-VCH GmbH AN - OPUS4-54711 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -