TY - CONF A1 - Radnik, Jörg A1 - Benettoni, P. A1 - Stryhanyuk, H. A1 - Wagner, S. A1 - Hachenberger, Y. A1 - Jungnickel, H. A1 - Tentschert, J. T1 - Analytical and Characterisation Excellence in nanomaterial risk assessment: A tiered approach Task2.5 N2 - The final results of Task 2.5 "Optimization of sample preparation for characterization of ENPs using TOF-SIMS under real-life conditions (a.) UfZ: polymer template; b.) BAM: pressing of pellets)" were presented. T2 - ACEnano General Meeting CY - Amsterdam, The Netherlands DA - 05.03.2020 KW - Nanoparticles KW - ToF-SIMS KW - Preparation PY - 2020 AN - OPUS4-50572 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mino, L. A1 - Pellegrino, F. A1 - Rades, Steffi A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan A1 - Spotto, G. A1 - Maurino, V. A1 - Martra, G. T1 - Beyond shape engineering of TiO2 nanoparticles: Post-synthesis treatment dependence of surface hydration, hydroxylation, Lewis acidity and photocatalytic activity of TiO2 anatase nanoparticles with dominant {001} or {101} facets JF - ACS Applied Nano Materials N2 - TiO2 anatase nanoparticles are among the relevant players in the field of light-responsive semiconductor nanomaterials used to face environmental and energy issues. In particular, shape-engineered TiO2 anatase nanosheets with dominant {001} basal facets gained momentum because of the possibility to exploit different and/or improved functional behaviors with respect to usual bipyramidal TiO2 anatase nanoparticles, mainly exposing {101} facets. Nevertheless, such behavior depends in a significant extent on the physicochemical features of surfaces exposed by nanosheets. They can vary in dependence on the presence or removal degree of capping agents, namely, fluorides, used for shape-engineering, and experimental investigations in this respect are still a few. Here we report on the evolution of interfacial/ surface features of TiO2 anatase nanosheets with dominant {001} facets from pristine nanoparticles fluorinated both in the bulk and at their surface to nanoparticles with F− free surfaces by treatment in a basic solution and to totally F− free nanoparticles by calcination at 873 K. The nanoparticles fluorine content and its subsequent evolution is determined by complementary techniques (ion chromatography, TOF-SIMS, XPS, AES, SEM-EDX), probing different depths. In parallel, the evolution of the electronic properties and the Ti valence state is monitored by UV−vis spectroscopy and XPS. The calcination treatment results in {001} facets poorly hydroxylated, hydrated, and hydrophilic, which appear as surface features consequent to the expected (1 × 4) reconstruction. Moreover, IR spectroscopy of CO adsorbed as probe molecule indicates that the Lewis acidity of Ti4+ sites exposed on (1 × 4) reconstructed {001} facets of calcined TiO2 nanosheets is weaker than that of cationic centers on {101} facets of bipyramidal TiO2 anatase nanoparticles. The samples have also been tested in phenol photodegradation highlighting that differences in surface hydration, hydroxylation, and Lewis acidity between TiO2 nanoparticles with nanosheet (freed by F− by calcination at 873 K) and bipyramidal shape have a strong impact on the photocatalytic activity that is found to be quite limited for the nanoparticles mainly exposing (1 × 4) reconstructed {001} facets. KW - Nanoparticles KW - TiO2 KW - F- doping KW - Shape-controlled nanoparticles KW - Nanosheets PY - 2018 DO - https://doi.org/10.1021/acsanm.8b01477 SN - 2574-0970 VL - 1 IS - 9 SP - 5355 EP - 5365 PB - ACS Publications CY - Washington, DC, U.S.A. AN - OPUS4-46157 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Radnik, Jörg A1 - Knigge, Xenia A1 - Andresen, Elina A1 - Resch-Genger, Ute A1 - Cant, D.J.H. A1 - Shard, A.G. A1 - Clifford, C.A. T1 - Composition, thickness, and homogeneity of the coating of core–shell nanoparticles—possibilities, limits, and challenges of X-ray photoelectron spectroscopy JF - Analytical and Bioanalytical Chemistry N2 - Core–shell nanoparticles have attracted much attention in recent years due to their unique properties and their increasing importance in many technological and consumer products. However, the chemistry of nanoparticles is still rarely investigated in comparison to their size and morphology. In this review, the possibilities, limits, and challenges of X-ray photoelectron spectroscopy (XPS) for obtaining more insights into the composition, thickness, and homogeneity of nanoparticle coatings are discussed with four examples: CdSe/CdS quantum dots with a thick coating and a small core; NaYF4-based upconverting nanoparticles with a large Yb-doped core and a thin Er-doped coating; and two types of polymer nanoparticles with a poly(tetrafluoroethylene) core with either a poly(methyl methacrylate) or polystyrene coating. Different approaches for calculating the thickness of the coating are presented, like a simple numerical modelling or a more complex simulation of the photoelectron peaks. Additionally, modelling of the XPS background for the investigation of coating is discussed. Furthermore, the new possibilities to measure with varying excitation energies or with hard-energy X-ray sources (hard-energy X-ray photoelectron spectroscopy) are described. A discussion about the sources of uncertainty for the determination of the thickness of the coating completes this review. KW - X-ray spectroscopy KW - Nanoparticles KW - Spectroscopy / Instrumentation KW - Spectroscopy / Theory PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-548305 DO - https://doi.org/10.1007/s00216-022-04057-9 VL - 414 IS - 15 SP - 4331 EP - 4345 PB - SpringerNature AN - OPUS4-54830 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sordello, F. A1 - Prozzi, M. A1 - Hodoroaba, Vasile-Dan A1 - Radnik, Jörg A1 - Pellegrino, F. T1 - Increasing the HER efficiency of photodeposited metal nanoparticles over TiO2 using controlled periodic illumination JF - Journal of Catalysis N2 - Although the use of noble metal catalysts can increase the efficiency of hydrogen evolution reaction, the process is still limited by the characteristics of the metal-hydrogen (M−H) bond, which can be too strong or too weak, depending on the metal employed. Studies revealed that the hydrogen affinity for the metal surface (i.e. H absorption/desorption) is regulated also by the potential at the metal nanoparticles. Through controlled periodic illumination (CPI) of a series of metal/TiO2 suspensions, here we demonstrated that an increase of the HER efficiency is possible for those photodeposited metals which have a Tafel slope below 125 mV. Two possible explanations are here reported, in both of them the M−H interaction and the metal covering level play a prominent role, which also depend on the prevailing HER mechanism (Volmer-Heyrovsky or Volmer-Tafel). KW - Controlled periodic illumination KW - Hydrogen evolution reaction KW - Titanium dioxide KW - Photoreforming KW - Volcano plot KW - Sabatier KW - Nanoparticles PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-589875 DO - https://doi.org/10.1016/j.jcat.2023.115215 VL - 429 SP - 1 EP - 7 PB - Elsevier B.V. AN - OPUS4-58987 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Knigge, Xenia A1 - Guo, Z. A1 - Valsami-Jones, E. A1 - Hodoroaba, Vasile-Dan A1 - Radnik, Jörg T1 - Influence of Sterilization on the Surface of Nanoparticles Studied with XPS / HAXPES in Comparison to SEM / EDS JF - Microscopy and Microanalysis N2 - Nanosafety is becoming increasingly important as nanomaterials are widely used in industrial processes and consumer products. For nanotoxicity measurements prior sterilization of the samples is necessary, but as structure activity relationships are made with properties of pristine particles, the question arises, if the sterilization process has an impact on the physico-chemical properties of nanoparticles and thus on the biological behavior. This question will be addressed in this talk. For this purpose, results from SEM and EDS measurements are combined with those of a novel lab-based HAXPES spectrometer in order to obtain a more complete picture. At the end, an influence of sterilization will be evident, which indicates a restructuring of the nanoparticles owing to sterilization. T2 - Microscopy & Microanalysis 2022 CY - Portland, USA DA - 31.07.2022 KW - XPS KW - HAXPES KW - SEM KW - EDS KW - Nanoparticles PY - 2022 DO - https://doi.org/10.1017/S1431927622004287 VL - 28 SP - 986 EP - 988 PB - Cambridge University Press AN - OPUS4-55352 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg A1 - Müller, Anja T1 - Introduction to photoelectronspectroscopy N2 - A short introduction to XPS/ESCA with the focus on nanoparticles and the preparation of such particles for the measurements T2 - Meeting of ACE Nano CY - Berlin, Germany DA - 18.02.2019 KW - ESCA/XPS KW - Nanoparticles KW - Preparation PY - 2019 AN - OPUS4-47437 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Knigge, Xenia A1 - Radnik, Jörg T1 - Physico-chemical characterization of Ce0.9Zr0.1O2 nanoparticles by XPS / HAXPES / SEM N2 - Here a dataset of XPS, HAXPES and SEM measurements for the physico-chemical characterization of Ce0.9Zr0.1O2 nanoparticles is presented. The measurements are part of the H2020 project “NanoSolveIT”. KW - HAXPES KW - XPS KW - SEM KW - Ce0.9Zr0.1O2 KW - Nanoparticles PY - 2023 DO - https://doi.org/10.5281/zenodo.7986672 PB - Zenodo CY - Geneva AN - OPUS4-57758 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Knigge, Xenia A1 - Radnik, Jörg T1 - Physico-chemical characterization of CeO2/Co3O4 nanoparticles by XPS / HAXPES / SEM N2 - Here a dataset of XPS, HAXPES and SEM measurements for the physico-chemical characterization of CeO2/Co3O4 nanoparticles is presented. The measurements are part of the H2020 project “NanoSolveIT”. KW - HAXPES KW - XPS KW - SEM KW - Nanoparticles KW - CeO2/Co3O4 PY - 2023 DO - https://doi.org/10.5281/zenodo.7989698 PB - Zenodo CY - Geneva AN - OPUS4-57760 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Knigge, Xenia A1 - Radnik, Jörg T1 - Physico-chemical characterization of Fe3O4 nanoparticles by XPS / HAXPES / SEM N2 - Here a dataset of XPS, HAXPES and SEM measurements for the physico-chemical characterization of Fe3O4 nanoparticles is presented. The measurements are part of the H2020 project “NanoSolveIT”. KW - HAXPES KW - XPS KW - SEM KW - Fe3O4 KW - Nanoparticles PY - 2023 DO - https://doi.org/10.5281/zenodo.7990085 PB - Zenodo CY - Geneva AN - OPUS4-57759 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Knigge, Xenia A1 - Radnik, Jörg T1 - Physico-chemical characterization of sterile Fe3O4 nanoparticles by XPS / HAXPES / SEM N2 - Here a dataset of XPS, HAXPES and SEM measurements for the physico-chemical characterization of sterile Fe3O4 nanoparticles is presented. The measurements are part of the H2020 project “NanoSolveIT”. KW - HAXPES KW - XPS KW - SEM KW - Fe3O4 KW - Nanoparticles PY - 2023 DO - https://doi.org/10.5281/zenodo.7990301 PB - Zenodo CY - Geneva AN - OPUS4-57764 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -