TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Inter-laboratory comparison on shape of bipyramidal TiO2 nanoparticles by TEM N2 - The TiO2 material selected for the present inter-laboratory comparison (ILC) was the bipyramidal anatase UT001 batch synthesized hydrothermally by University of Turin in the frame of the EU/FP7 Project SETNanoMetro and carefully prepared on TEM grids by BAM to be distributed to the ILC participants. A clear measurement protocol including data analysis and reporting (including an xls reporting template) has been also prepared by BAM. 14 of 18 participants have measured and reported results which have been already checked by BAM as being conform to the agreed protocol. After receiving the last results (of 4 participants) the ILC data evaluation will be carried out by BAM in line with agreed ISO/TC229 procedures as for the other case sudies. T2 - Annual Meeting of ISO/TC 229 Nanotechnologies CY - Singapore, Republic of Singapore DA - 07.11.2016 KW - TiO2 KW - Nanoparticles KW - Inter-laboratory comparison KW - Shape KW - TEM KW - Particle size distribution PY - 2016 AN - OPUS4-38868 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Iannarelli, L. T1 - Shape engineered TiO2 nanoparticles in Caenorhabditis elegans: a Raman imaging based approach to assist tissue-specific toxicological studies N2 - In vivo detailed spatial distribution of TiO2 NPs was here investigated for the first time using a 2D chemical imaging analysis based on Confocal Raman Spectroscopy. The invertebrate nematode C. elegans was employed as prototypical model of living organism. Rod, bipyramidal and quasi-spherical engineered TiO2 NPs with different primary particle sizes and agglomeration states were prepared, characterized and then administered to nematodes. Exploiting the typical fingerprint of TiO2 in the Raman spectrum, we monitored the biodistribution of NPs inside the worm using a non-invasive, label-free method. The high spatial resolution chemical imaging and the specificity of the Raman technique in the localization of TiO2 NPs helped in the design of behavioral C. elegans studies aimed at elucidating the relationship among the size, shape, and agglomeration state of NPs and their ability to induce specific toxic effects. T2 - 16th European Conference on Applications of Surface and Interface Analysis ECASIA'15 CY - Fortaleza, Brazil DA - 14.08.2016 KW - TiO2 KW - Nanoparticles KW - Raman imaging KW - Toxicological studies PY - 2016 AN - OPUS4-38240 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, R. T1 - SEM or TEM for the characterization of nanoparticles? N2 - Scanning Electron Microscopy (SEM) or Transmission Electron Microscopy (TEM) ? This is a question, nowadays discussed in EM labs of research and industry involved in the characterization and metrology of nanoparticles. The Scanning principle is adapted to TEM, the Transmission mode is adapted to Ultra High Resolution SEM. Can modern SEM replace TEM, reach atomic resolution even without Cs corrector or nm lateral resolution for X-ray Spectroscopy (EDX)? Due to the development of a New Cold Field Emission (NCFE) electron source Hitachi SEMs SU9000 and SU8200 can deliver routinely sub-nm image resolution and EDX mappings at very high count rates and a lateral EDX resolution of a few nm. A TiO2 sample provided by BAM was analysed at 30 kV using low kV STEM – simultaneously with the Through-the-lens (TTL) SE detector, the Bright Field transmission and Dark Field transmission signals. By this method a pixel-precise information of the particle’s surface using SE, its chemical nature using DF-STEM and its crystalline structure using Bright Field signal is given in one 40sec scan. The advantage of this observation mode compared to Ultra Low Voltage imaging is outlined. T2 - 7. NRW Nano-Konferenz CY - Münster, Germany DA - 07.12.2016 KW - SEM KW - TEM KW - Nanoparticles PY - 2016 AN - OPUS4-38936 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Available particle-sizing techniques at work for the classification as a nanomaterial - How reliable it really is? N2 - The capability of currently available particle sizing techniques for reliable classification of materials that potentially fall under the EU Definition of a nanomaterial is discussed. A systematic quantitative evaluation of the sizing techniques is presented together with representative case studies of analysis of industrially relevant materials. Recommendations on the most appropriate and efficient use of techniques for different types of material are given. T2 - Frontiers of Nanomaterial Characterization CY - Tokyo, Japan DA - 28.05.2017 KW - Nanomaterial classification KW - Nanoparticles KW - Number-weighted median size KW - Particle size analysis KW - Characterization techniques PY - 2017 AN - OPUS4-40474 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Evaluation of particle sizing techniques for implementation of the EC Definition of a nanomaterial N2 - Many techniques are available for measuring particle size distribution. For ideal materials (spherical particles, well dispersed) it is possible to evaluate the Performance of these methods. The performance of the analytical instrumentation for the purpose of classifying materials according to EC Definition is unknown. In this work the performance of commercially available particle sizing techniques on representative NanoDefine set of real-world testing materials (RTM) and quality control materials (QCM) for the implementation of the Definition is evaluated. T2 - Final NanoDefine Outreach Event Classification of nanomaterials according to the EU definition CY - Brüssel, Belgium DA - 19.09.2017 KW - Nanomaterial classification KW - Particle sizing techniques KW - Nanoparticles KW - EC definition of a nanomaterial PY - 2017 UR - http://www.nanodefine.eu/index.php/nanodefine-meetings/125-final-outreach-event-2017 AN - OPUS4-42507 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Volume specific surface area (VSSA) by BET: concept and demonstration on industrial materials N2 - Volume specific surface area (VSSA) as measured by BET constituites a simple and reliable solution to (most) powders. Porous, coated, polydisperse/multimodal materials are to be treated with care, i.e. doubled by analysis with electron microscopy or more advanced BET analysis (e.g. t-plot)for each material in part. T2 - Final NanoDefine Outreach Event: Classification of nanomaterials according to the EU definition CY - Brüssel, Belgium DA - 19.09.2017 KW - VSSA KW - BET KW - Nanoparticles KW - Powder KW - Nanomaterial classfication PY - 2017 UR - http://www.nanodefine.eu/index.php/nanodefine-meetings/125-final-outreach-event-2017 AN - OPUS4-42509 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Measurement of nanoparticle size and shape distribution – Current situation and outlook N2 - The EC Recommendation on the definition of nanomaterial, based solely on size of the constituent particles, foresees development of harmonised measurement methods ensuring ‘consistent results across materials and over time’. The EU/FP7 research project NanoDefine has been exclusively dedicated to support the implementation of this EC Recommendation for the European Union’s legislation. For the first time, measurement techniques able to determine the size of nanoparticles have been evaluated systematically on a well-defined set of quality control materials (spherical, monodisperse) as well as industrial materials of complex shapes and considerable polydispersity. Particularly based on the analytical performance of the measurement techniques as tested on the challenging real-world particulate materials, it was possible to formulate recommendations for use of a new tiered approach consisting of screening and confirmatory techniques. Thus, a consistent framework of guidance for nanomaterial identification according to the EC Definition has been issued in form of the NanoDefiner e-tool, with a transparent decision flow scheme and an extensive user manual. Selected examples of analysis and classification as nano-/non-nanomaterials will be given, highlighting the limits of applicability of the available measurement techniques in dependence on sample properties. On some recent relevant developments in sample preparation – as a crucial part for an accurate analysis - will be also reported. Further, ISO/TC 229 ‘Nanotechnologies’ activities aiming at establishing accurate TEM and SEM measurement of NP size and shape as robust, traceable, standard procedures are highlighted. With participation of BAM, study groups have been organizing inter-laboratory comparisons on well-selected NP systems according to the market needs, such as aggregated or shape-controlled titania nano-powder for which size and shape distribution of primary particles must be measured accurately. T2 - Symposium Preparation, Characterization and Processing of Nano and Submicron Powders CY - Berlin, Germany DA - 14.06.2018 KW - Nanoparticles KW - Nanomaterial KW - EC definition KW - Nanoparticle size distribution PY - 2018 AN - OPUS4-45191 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Shape controlled TiO2 nanoparticles as candidates for nano-CRM’s – an ISO case study N2 - Extraction of true, 3D shape (and size) of non-spherical nanoparticles (NPs) is associated with errors by conventional 2D electron microscopy using projection images. Significant efforts within the ISO technical committee TC 229 ‘Nanotechnologies’ are aimed at establishing accurate TEM and SEM measurement of NP size and shape as robust, standard procedures. Study groups have been organizing inter-laboratory comparisons on well-selected NP systems according to the market needs, such as aggregated titania nano-powder for which size and shape distribution of primary crystallites of irregular shape must be measured accurately. To be noticed is e. g. the fact that the measurement procedure allows only manual selection of the particles clearly distinguishable for analysis as well as manual definition of the contour of the imaged NPs. An inter-laboratory exercise on titania NPs (pure anatase, grown by hydrothermal synthesis) of well-defined non-spherical shape, i.e. bipyramidal has been recently started within ISO/TC 229 under similar conditions as for the irregular shaped titania. Overlapped particles were allowed to be considered, as long as they are clearly distinguishable. One decisive NP selection criterion was to analyze only those NPs with a roundness value below 0.7, i.e. the NPs laying on the support foil and, hence, with projection areas clearly deviating from perfect circles (R=1). The overall evaluation (for 15 labs) of the size descriptors (area, Feret, minFeret, perimeter) and shape descriptors (aspect ratio, roundness, compactness, extent) by analysis of variance is just to be finished and included in ISO/WD 21363 Nanotechnologies -- Protocol for particle size distribution by transmission electron microscopy. T2 - NanoWorkshop 2018 (Workshop on reference nanomaterials, current situation and needs: development, measurement, standardization) CY - Berlin, Germany DA - 14.05.2018 KW - Titanium oxide KW - Nanoparticles KW - Shape-controlled KW - Electron microscopy KW - Reference material PY - 2018 AN - OPUS4-44996 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Controlled deposition of nanoparticles by electrospray for improved analysis by imaging techniques N2 - Of many experimental techniques for measuring particle sizes and size distributions, electron microscopy (EM) is still considered as the gold standard, especially in the nano range (1–100 nm). Furthermore, high-resolution X-ray spectroscopy (EDX) in conjunction with EM can be applied to individual NPs. Preparation of an EM sample for generic particulate materials is a difficult task. Usually the particles in a suspension are deposited on a support. However, this procedure includes the drying of larger solvent amounts on the substrate itself, and this can affect the spatial distribution of the deposited particles. One possibility to overcome this is the use of an electrospray system, where the suspension of particles is sprayed onto the substrate in charged droplets that are so small that they either dry off on the substrate immediately without affecting the position of particles, or even already during their flight time to the substrate. Additionally, the charging of particles minimizes agglomeration and aggregation, maximizing the collection of the EM grids. The prototype of an electrospray deposition system from RAMEM under its trademark IONER (www.ioner.eu) was tested. Electrospray is theoretically described since a long time, but no dedicated commercial instruments are available for the preparation of TEM grids yet, apart from electrostatic deposition of aerosols.2 Several materials have been sprayed onto TEM grids and the resulting particle distributions were evaluated. Operation parameters such as the sample flow-rate, capillary – substrate distance, electric field strength and sampling period length have been optimized. It was found that the particles deposited by electrospray generally show a much more homogeneous spatial distribution on the substrate and a substantial increase of the number of single particles (suited to automatic analysis). T2 - RSC-NPL Symposium: Nanoparticle concentration – critical needs and state-of-the-art measurement CY - London, UK DA - 24.04.2018 KW - Electrospray deposition KW - Nanoparticles KW - Electron microscopy PY - 2018 AN - OPUS4-44802 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Volume specific surface area (VSSA) by BET as a reliable metric for (nano)particle size analysis for powders N2 - We discuss the role of the volume specific surface area (VSSA) as determined from the specific surface area measured by the (extended) Brunauer-Emmett-Teller (BET) technique, in the identification process of powdered nano- and non-nanomaterials in line with the EU definition of nanomaterial. Results obtained in the NanoDefine project demonstrate that under appropriate conditions, VSSA can be used as proxy to the number-based particle size distribution. The extent of agreement between nano/non-nano classification by electron microscopy (EM) and classification by VSSA is investigated systematically on a large set of diverse particulate substances, representing most of the cases expected in regulatory practice. Thus, parameters such as particle shape, size polydispersity/multi-modality, and particle (inner or coating) porosity are evaluated. Based on these results, we derive a tiered screening strategy for powders, involving the use of VSSA for the purpose of implementing the definition of nanomaterial, and recommend it for inclusion in a technical guidance for the implementation of the definition. T2 - RSC-NPL Symposium: Nanoparticle concentration – critical needs and state-of-the-art measurement CY - London, UK DA - 24.04.2018 KW - Nanoparticles KW - Nanomaterial KW - Particle size distribution KW - BET KW - VSSA PY - 2018 AN - OPUS4-44801 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Improved traceability chain of nanoparticle size measurements N2 - The overall objective of project Improved traceability chain of nanoparticle size measurements is to improve the traceability chain for nanoparticle size measurements. The main impact will be achieved by manifold contributions to standard documents for CEN/TC 352 “Nanotechnologies”, which directly addresses the research needs of CEN, CENELEC and ETSI mandated by EC to develop standards for methods and reference materials to accurately measure the size and size distribution of nanoparticles. This will take place in collaboration with ISO/TC229 ‘Nanotechnologies’, ISO/TC24/SC4 ‘Particle characterization’ and ISO/TC201 ‘Surface analysis’/ SC9 ‘Scanning probe microscopy’. T2 - EMPIR 2017 Review Conference CY - Monaco DA - 9.11.2017 KW - Nanoparticles KW - Traceability KW - Electron micrsocopy KW - Size KW - Shape PY - 2017 AN - OPUS4-43019 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sötebier, Carina A1 - Bierkandt, Frank A1 - Rades, Steffi A1 - Jakubowski, Norbert A1 - Panne, Ulrich A1 - Weidner, Steffen T1 - Sample loss in asymmetric flow field-flow fractionation coupled to inductively coupled plasma-mass spectrometry of silver nanoparticles N2 - In this work, sample losses of silver nanoparticles (Ag NPs) in asymmetrical flow field-flow fractionation (AF4) have been systematically investigated with the main focus on instrumental conditions like focusing and cross-flow parameters as well as sample concentration and buffer composition. Special attention was drawn to the AF4 membrane. For monitoring possible silver depositions on the membrane, imaging laser ablation coupled to inductively coupled plasma mass spectrometry (LA-ICP-MS) was used. Our results show that the sample residue on the membrane was below 0.6% of the total injected amount and therefore could be almost completely avoided at low sample concentrations and optimized conditions. By investigation of the AF4 flows using inductively coupled plasma mass spectrometry (ICP-MS), we found the recovery rate in the detector flow under optimized conditions to be nearly 90%, while the cross-flow, slot-outlet flow and purge flow showed negligible amounts of under 0.5%. The analysis of an aqueous ionic Ag standard solution resulted in recovery rates of over 6% and the ionic Ag content in the sample was found to be nearly 8%. Therefore, we were able to indicate the ionic Ag content as the most important source of sample loss in this study. KW - Asymmetric flow filed-flow fractionation KW - ICP-MS KW - Nanoparticles KW - Sample loss KW - Quantification PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-336171 DO - https://doi.org/10.1039/c5ja00297d SN - 0267-9477 SN - 1364-5544 VL - 30 IS - 10 SP - 2214 EP - 2222 PB - Royal Society of Chemistry CY - London AN - OPUS4-33617 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Usmani, Shirin T1 - Wood protection with nanoparticles: MgF2 and CaF2 N2 - Alkaline earth metal fluoride nanoparticles have been investigated for application in wood protection. Sols of MgF2 and CaF2 were synthesized and their efficacy was tested against fungi and termites (Rehmer 2016, Krahl et al. 2016). The sols were characterized by XRD and SEM. The wood specimens were vacuum impregnated with nanoparticles and then exposed to fungi and termites according to EU certified test conditions. Our results show that wood impregnated with metal fluoride nanoparticles significantly reduce cellulose hydrolysis by fungi and termites. The wood samples were exposed to brown-rot fungi; Coniophora puteana and Poria placenta. Between the two fungi, the overall mass lost due to fungal degradation was lower for treated (MgF2 and CaF2) wood samples exposed to Coniophora puteana. Thus, the metal fluoride nanoparticles impregnated in the wood samples were more efficient in reducing cellulose degradation from Coniophora puteana than from Poria placenta. However the mass loss in samples treated with MgF2 was similar to those treated with CaF2, irrespective of type of fungi. Therefore, it is likely that fungal degradation in treated samples was dependent on the biocidal action of fluorides rather than on the differences in chemical and physical properties of MgF2 and CaF2, respectively. Conversely, for termite exposure, wood samples treated with MgF2 had lower cellulose degradation compared to those treated with CaF2. A possible explanation for this difference in results could be fungi and termites use separate mechanisms for cellulose hydrolysis which will be further investigated. Future experiments include testing the leaching potential of MgF2 and CaF2 nanoparticles from wood. The results from the leaching experiment will test if metal fluoride nanoparticles can provide long-term and environmentally safe protection to wood. T2 - International Research Group (IRG48) Scientific Conference on Wood Protection CY - Ghent, Belgium DA - 04.06.2017 KW - Fluoride KW - Nanoparticles KW - Brown-rot fungi KW - Termites PY - 2017 AN - OPUS4-41019 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Usmani, Shirin M. T1 - Wood protection with MgF2 and CaF2 nanoparticles N2 - Sol-gel synthesis was used to prepare nanoparticles of MgF2 and CaF2. These nanoparticles were tested for their application in wood protection. In comparison to control samples, wood specimens treated with MgF2 and CaF2 showed lower mass loss under exposure to termites and fungi. Samples treated with MgF2 performed better at protecting wood from cellulose degradation when exposed to termites. Conversely, in the presence of fungi, mass loss in treated samples was similar irrespective of the chemical composition (MgF2 and CaF2) of the treatment. A possible explanation for this difference in results between termites and fungi could be their different mechanism of cellulose hydrolysis. Thus, future wood preservatives would need to be customized according to their specific application. T2 - 19th International Sol-Gel Conference CY - Liege, Belgium DA - 03.09.2017 KW - Nanoparticles KW - Wood protection KW - Fungi KW - Termites PY - 2017 AN - OPUS4-42541 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nakadi, Flavio V. T1 - Single-event analysis of discrete entities using microwave-induced nitrogen plasma–mass spectrometry N2 - ICP-MS has become a standard for (ultra)trace elemental analysis due to its excellent sensitivity and multi-element capabilities. However, its widespread use is hampered by spectral interferences—especially in the low mass range (<81 amu)—primarily arising from Ar-based polyatomic ions, such as ArO+ and Ar2+, which compromise the accurate quantification of key elements like Fe and Se.1 Over the years, improvements such as collision/reaction cells and sector-field configurations have helped mitigate these interferences, albeit often at the cost of instrument complexity and increased operational burden.The microwave-induced nitrogen plasma (MINP) source, sustained by microwaves at atmospheric pressure and using nitrogen as the plasma gas, offers a fundamentally different plasma environment. Nitrogen is not only more economical (40-60%) and readily available than Ar, but also avoids the generation of problematic Ar-based interferences. While MINP had been previously applied in optical emission and bulk mass spectrometry,2 its implementation in single-event detection had not yet been demonstrated. This study pioneers the application of MINP-MS in single-event mode for real-time, high-throughput characterization of NPs, cells, and MPs. The evaluation began with Fe2O3 NPs monitoring the 56Fe nuclide, with a limit of detection of 8.6 ag for Fe, equivalent to a particle size threshold of 19 nm—surpassing the detection capabilities of quadrupole-based ICP-MS systems. Size distribution results obtained by SP-MINP-MS for Fe2O3 NPs (20–70 nm) matched closely with transmission electron microscopy (TEM) and dynamic light scattering (DLS), confirming the method’s accuracy. For Se, despite its high ionization energy, metallic SeNPs (150 and 250 nm) were reliably quantified by monitoring 80Se. A calibration curve constructed using SeNP standards yielded excellent linearity (R2 = 0.9994). This approach was further extended to single-cell analysis, using Se-enriched yeast (SELM-1 CRM) as a model. A transport efficiency-independent calibration strategy was employed, relying on SeNPs to determine Se content per cell. The results showed strong agreement with data from conventional SC-ICP-MS, with average Se masses of ~65 fg per cell, validating the performance of SC-MINP-MS for biological systems. Additionally, the instrument's capability to handle large, low atomic number particles was demonstrated via the analysis of polystyrene (PS) and polytetrafluoroethylene (PTFE) MPs. These MPs (2.5–3.0 µm) were quantified by monitoring 12C+ signals and applying a calibration strategy using citric acid as a standard. The resulting size distributions closely matched nominal sizes, reinforcing the system’s robustness for micrometer-sized polymeric materials. Event durations ranging from 470 to over 900 µs were consistent with literature values for single-entity ICP-MS and correlated well with particle size. These findings establish single-event MINP-MS as a promising analytical platform for analyzing discrete entities. It provides significant advantages over conventional Ar-based ICP-MS, including reduced interferences, lower operational cost, and comparable or superior sensitivity for analytes such as Fe and Se. By avoiding the limitations of Ar-based plasmas and enabling accurate quantification across a wide range of particle types and sizes, MINP-MS in single-event mode opens new avenues for high-resolution, interference-free elemental analysis at the individual entity level. T2 - 17th Rio Symposium on Atomic Spectrometry (17th RSAS) CY - São Pedro City, Brazil DA - 09.11.2025 KW - MICAP-MS KW - Nitrogen plasma KW - Nanoparticles KW - Cells KW - Microplastic KW - Single particle KW - Single event KW - ICP-MS PY - 2025 AN - OPUS4-64954 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heilmann, Maria T1 - Size-Tunable Ni-Cu Core-Shell Nanoparticles: Structure, Composition, and Catalytic Activity N2 - Nanoparticles (NPs) have become important materials for a variety of chemical technologies, including catalysis. One of the main challenges is the reduction of green house gases, such as CO2. One opportunity besides the capturing is the conversion to synthesis gas via the reverse water-gas shift reaction. A facile and efficient method is described for the solvothermal synthesis of size-tunable, stable, and uniform NiCu core-shell NPs. The diameter of the NPs can be tuned in a range from 6 nm to 30 nm and the Ni:Cu ratio from 30:1 to 1:1. The NPs are structurally characterized with combination of transmission electron microscopy, anomalous small-angle X-ray scattering, X-ray photoelectron spectroscopy, and X-ray absorption fine structure. Using these analytical methods, a core-shell-shell structure their chemical composition is elucidated. A depletion from the core to the shell is observed, with the core consisting of NiCu alloy, surrounded by an inner Ni-rich shell and an outer NiO shell. The SiO2-supported NiCu core-shell NPs show pronounced selectivity of >99% for CO in the catalytic reduction of CO2 to CO using hydrogen as reactant (reverse water–gas shift reaction). T2 - Nanoalloys: recent developments and future perspectives Faraday Discussion CY - London, UK DA - 21.09.2022 KW - Nanoparticles KW - Core-shell KW - Catalysis PY - 2022 AN - OPUS4-56831 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heilmann, Maria A1 - Prinz, Carsten A1 - Bienert, Ralf A1 - Wendt, R. A1 - Kunkel, B. A1 - Radnik, Jörg A1 - Hoell, A. A1 - Wohlrab, S. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Emmerling, Franziska T1 - Size-Tunable Ni–Cu Core–Shell Nanoparticles—Structure, Composition, and Catalytic Activity for the Reverse Water–Gas Shift Reaction N2 - A facile and efficient methodology is described for the solvothermal synthesis of size-tunable, stable, and uniform NiCu core–shell nanoparticles (NPs) for application in catalysis. The diameter of the NPs is tuned in a range from 6 nm to 30 nm and to adjust the Ni:Cu ratio from 30:1 to 1:1. Furthermore, the influence of different reaction parameters on the final NPs is studied. The NPs are structurally characterized by a method combination of transmission electron microscopy, anomalous small-angle X-ray scattering, X-ray absorption fine structure, and X-ray photoelectron spectroscopy. Using these analytical methods, it is possible to elucidate a core–shell–shell structure of all particles and their chemical composition. In all cases, a depletion from the core to the shell is observed, with the core consisting of NiCu alloy, surrounded by an inner Ni-rich shell and an outer NiO shell. The SiO2-supported NiCu core–shell NPs show pronounced selectivity of >99% for CO in the catalytic reduction of CO2 to CO using hydrogen as reactant (reverse water–gas shift reaction) independent of size and Ni:Cu ratio. KW - Nanoparticles KW - Core-shell KW - Catalysis PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543606 DO - https://doi.org/10.1002/adem.202101308 SN - 1438-1656 SP - 1 EP - 13 PB - Wiley VCH AN - OPUS4-54360 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heilmann, Maria T1 - Synthesis of bimetallic nickel nanoparticles as catalysts for the Sabatier reaction N2 - Nanoparticles (NP) have become important materials for a variety of chemical technologies. The enhanced surface-area-to-volume ratio of NPs, making them excellent for use as catalyst, in analytical assays, and for antimicrobial applications. Nickel NPs have exhibited immense potential as important catalyst for the Sabatier reaction, i.e. converting waste to energy via transformation of CO2 into CH4, and could replace the rare earth elements such as Ru, PT, or Rh. In this work we describe the solvothermal synthesis of monometallic and bimetallic nickel nanoparticles. Monodisperse monometallic Ni NPs were synthesized using Oleylamin as solvent and reducing agent. The nanoparticles were investigated using small angle scattering (SAXS), scanning transmission electron microscopy (STEM) and energy dispersive X-ray spectroscopy (EDX), showing that the NPs are stable while the surface is not entirely covered. However, Ni has a high propensity to undergo oxidation, and becoming deactivated by coke formation. Hence, we further explore the preparation of bimetallic NPs, where a second metal is added to stabilize the Ni. Bimetallic Cu-Ni NPs were synthesized by simultaneous solvothermal reduction. These bimetallic NPs exhibit excellent catalytic properties are promising candidates to be used as catalysts for efficient energy storage. T2 - 31. Tag der Chemie 2019 CY - Berlin, Germany DA - 11.07.2019 KW - Nanoparticles KW - Catalysis KW - Synthesis PY - 2019 AN - OPUS4-50171 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heilmann, Maria T1 - Synthesis of bimetallic nickel nanoparticles as catalysts for the Sabatier reaction N2 - Nanoparticles (NPs) have become important materials for a variety of chemical technologies. The enhanced surface-area-to-volume ratio of NPs, making them excellent for use as catalyst, in analytical assays, and for antimicrobial applications. Nickel NPs have exhibited immense potential as important catalyst for the Sabatier reaction, i.e. converting waste to energy via transformation of CO2 into CH4, and could replace the rare earth elements such as Ru, PT, or Rh. In this work we describe the solvothermal synthesis of monometallic and bimetallic nickel nanoparticles. Monodisperse monometallic Ni NPs were synthesized using Oleylamin as solvent and reducing agent. The nanoparticles were investigated using small angle scattering (SAXS), scanning transmission electron microscopy (STEM) and energy dispersive X-ray spectroscopy (EDX), showing that the NPs are stable while the surface is not entirely covered. However, Ni has a high propensity to undergo oxidation, and becoming deactivated by coke formation. Hence, we further explore the preparation of bimetallic NPs, where a second metal is added to stabilize the Ni. Bimetallic Cu-Ni NPs were synthesized by simultaneous solvothermal reduction. These bimetallic NPs exhibit excellent catalytic properties are promising candidates to be used as catalysts for efficient energy storage. T2 - Adlershofer Forschungsforum 2019 CY - Berlin, Germany DA - 11.11.2019 KW - Nanoparticles KW - Catalysis KW - Synthesis PY - 2019 AN - OPUS4-50173 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heilmann, Maria T1 - Synthesis of bimetallic nickel nanoparticles for catalysis N2 - We present the synthesis of monodisperse monometallic Ni nanoparticles (NPs) and bimetallic NiCu respectively NiCo NPs. The NPs were investigated using SAXS, STEM, EDX, and XANES, showing that the NPs are size tunable and stable while the surface is not entirely covered. Nickel NPs have exhibited immense potential as important catalyst for the Sabatier reaction, i.e. converting waste to energy via transformation of CO2 into CH4. T2 - 11th Joint BER II and BESSY II User Meeting CY - Berlin, Germany DA - 04.12.2019 KW - Nanoparticles KW - Catalysis KW - Synthesis PY - 2019 AN - OPUS4-50172 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -