Periodic Reporting for period 2 - LINCHPIN (A platform to LINk between CHemistry and PhysIcs of colloidal Nanomaterials)
Berichtszeitraum: 2021-07-01 bis 2022-12-31
Today’s emerging questions in colloidal science go far beyond the precise control of nanoparticle size. The synthetic and theoretical efforts focus on a wide range of nanomaterials with unique electronic properties as they carry on a potential to have impact on highly relevant societal themes ranging from electronic devices, energy conversion to energy storage. The particularly important recent examples include the transition metal chalcogenides, and nitrides. In this context studying the electronic structure of the central metal atom and differentiating between various metal ligands during synthesis has become of paramount importance for the chemistry of materials. The current scientific climate sets the groundwork for photon-in-photon-out spectroscopy to take chemistry of nanomaterials to a new level and to make a LINk between the CHemical and PhysIcal aspects of the emergence of Nanostructures in solution (LINCHPIN).
We will achieve the ambitious goal of filling the gap on the reaction time scale, in the vision exceeding the conventional approaches, which includes the novel concept of a platform to study the chemical reactions at elevated temperatures and at the relevant time scales.
We will achieve the ambitious goal of filling the gap on the reaction time scale, in the vision exceeding the conventional approaches, which includes the novel concept of a platform to study the chemical reactions at elevated temperatures and at the relevant time scales.
We have started working on exploring effects, which are of fundamental importance for the in situ experiments in solution but were so far not addressed. They evolved around the question of sensitivity of the method in solution and if and how x-rays change the chemical reactions. We first showcase, on example of CoO formation (Nature Comm. 2021) and Cu hollowing (Nature Comm. 2022), how in situ studies with so called “photon-hungry” techniques can be realized.
We demonstrate that the high energy resolution of HERFD-XANES makes it sensitive to subtle changes in the local chemical environment of the absorbing atom. We reveal that initially cobalt (III) acetylacetonate precursors rapidly reduces to square-planar cobalt (II) acetylacetonate and coordinates to two solvent molecules and only then condensate to cobalt oxide. Thus, we directly access the molecular level of the nanomaterial synthesis. Moreover, we have developed protocols how to estimate and mitigate the beam damage during the colloidal synthesis in non-aqueous environment for micro- and nano-focused X-ray beam.
Additionally, in a collaboration with Prof. Sikora (expert in magnetic materials) from AGH university in Cracow we could show that Magnetic Circular Dichroism in Resonant Inelastic X-ray Scattering enables assessment of the site distribution and magnetic state of metal ions in the superparamagnetic iron oxide nanoparticles. Here we contributed with our reactor for studies in colloidal solution (Nanoscale 2020).
In parallel we have been working on (a) in situ photon-in photon-out studies of transition metal sulfides and nitrides growth in non-aqueous solution and (b) micro-reactors engineering to address shorter reaction time scales.
We demonstrate that the high energy resolution of HERFD-XANES makes it sensitive to subtle changes in the local chemical environment of the absorbing atom. We reveal that initially cobalt (III) acetylacetonate precursors rapidly reduces to square-planar cobalt (II) acetylacetonate and coordinates to two solvent molecules and only then condensate to cobalt oxide. Thus, we directly access the molecular level of the nanomaterial synthesis. Moreover, we have developed protocols how to estimate and mitigate the beam damage during the colloidal synthesis in non-aqueous environment for micro- and nano-focused X-ray beam.
Additionally, in a collaboration with Prof. Sikora (expert in magnetic materials) from AGH university in Cracow we could show that Magnetic Circular Dichroism in Resonant Inelastic X-ray Scattering enables assessment of the site distribution and magnetic state of metal ions in the superparamagnetic iron oxide nanoparticles. Here we contributed with our reactor for studies in colloidal solution (Nanoscale 2020).
In parallel we have been working on (a) in situ photon-in photon-out studies of transition metal sulfides and nitrides growth in non-aqueous solution and (b) micro-reactors engineering to address shorter reaction time scales.
To advance fundamental knowledge in chemistry of electronic nanomaterials, our main objective is in the further course of LINCHPIN to rigorously study the emergence of electronic structure in solution with photon-in photon-out spectroscopy with high temporal, spatial and energy resolution. So far we have mainly addressed the energy resolution, thus our future efforts towards high temporal and spatial resolutions will be intensify. This will be reached with the micro-reactor, which is currently under development.
The tight coupling between the development of a methodology and its application to study a highly relevant class of nanomaterials, for example 2D-layered structures and metal nitrides, is expected to accelerate both knowledge acquisition and the transfer of engineering-based developments and tools into new scientific applications. The proposed micro-reactors along with experimental spectroscopic protocols and the concurrent fundamental knowledge create a paradigm shift for in situ time resolved experiments with an impact in many other fields from catalysis, and sustainable flow chemistry to biomedical applications.
The tight coupling between the development of a methodology and its application to study a highly relevant class of nanomaterials, for example 2D-layered structures and metal nitrides, is expected to accelerate both knowledge acquisition and the transfer of engineering-based developments and tools into new scientific applications. The proposed micro-reactors along with experimental spectroscopic protocols and the concurrent fundamental knowledge create a paradigm shift for in situ time resolved experiments with an impact in many other fields from catalysis, and sustainable flow chemistry to biomedical applications.