Two dimensional spectroscopy is a powerful dynamical study method that has been developed in the last two decades. In 2D IR there are three experimental time periods during which the system vibrational modes of interest are excited, evolved to different frequencies and finally emit a non linear signal that is heterodyne detected by temporal and spatial overlapping with a local oscillator. With this approach we are able to determine vibrational coupling, mode anharmonicities and relative orientation of transition dipole moments which help us to obtain the structural kinetics and molecular dynamics of the system.We can study interaction between functional groups which can be indicators of bond formation or dissociation using 2D IR.[3] In this work we aim to use 2D IR to compare the molecular dynamic in a monolayer interface of an immobilized catalyst in the presence and absence of solvent. Homogenous catalysts have the advantage of higher interaction with the reactants and thus showing high efficiency. However, because of difficulties in separation of such catalysts from the products and non-reusability, immobilization of homogeneous catalysts has been considered. Although immobilization decreases the expenses of separation and purifying the products which is especially important in pharmaceutical industries, it does not always maintain the high activity of the homogeneous catalysts. Solvent addition to immobilized catalysts can affect its efficiency because of changing the molecular dynamic of the system.[4] 2D IR approach help us to understand the structural evolution rate of such systems through spectral diffusion analysis and vibrational relaxation lifetime.
Single atom catalysts (SACs) based on 2D materials are identified to be efficient in many catalytic reaction. In this work, the catalytic performance of Pd/Pt embedded planar carbon nitride (CN) for CO oxidation, has been investigated via spin$-$polarized density functional theory calculations. We find that Pd/Pt can be firmly anchored in the porous CN monolayer due to the strong hybridization between Pd/Pt-d orbitals and adjacent N-2p orbitals. The resulting high adsorption energy and large diffusion barrier of Pd/Pt, ensuring the remarkable stability of the catalyst Pd/Pt@CN during CO oxidat…
Surface roughness of particle monolayer is one of its fundamental characteristics, conventionally described in terms of power spectral density. We derive a general equation for this function and demonstrate its similarity to those applied in the theory of scattering. We validate our analytical results by comparison with numerical results for a system with parameters corresponding to typical experimental conditions. We also demonstrate a practical application of our approach for spectral analysis of the monolayer image. Our theoretical model provides a general framework for a cheap and easy par…
Prediction of CO2 reduction reaction intermediates and products on transition metal-doped r-GeSe monolayers:A combined DFT and machine learning approach
Molecular stochastic process on gold surface observed in broadband-infrared, background-suppressed, sum frequency generation spectroscopy: picosecond heat transfer to self-assembled monolayers
Chiral Porphyrin Monolayers on Ferromagnetic Thin Films: Ultrafast Spectroscopy of Hybrid Interfaces
Faculty of Chemistry, Adam Mickiewicz University（亚当·密茨凯维奇大学化学系）；Center for Advanced Technologies, Adam Mickiewicz University（亚当·密茨凯维奇大学先进技术中心）；Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research（德累斯顿-罗斯多夫亥姆霍兹中心离子束物理与材料研究所）；Faculty of Physics and Astronomy, Adam Mickiewicz University（亚当·密茨凯维奇大学物理与天文学系）
We present a many-body formalism for the simulation of time-resolved nonlinear spectroscopy and apply it to study the coherent interaction between excitons and trions in doped transition-metal dichalcogenides. Although the formalism can be straightforwardly applied in a first-principles manner, for simplicity we use a parameterized band structure and a static model dielectric function, both of which can be obtained from a calculation using the $GW$ approximation. Our simulation results shed light on the interplay between singlet and triplet trions in molybdenum- and tungsten-based compounds. O…
Monolayers of transition metal dichalcogenides (TMdC) are promising candidates for realization of a new generation of optoelectronic devices. The optical properties of these two-dimensional materials, however, vary from flake to flake, or even across individual flakes, and change over time, all of which makes control of the optoelectronic properties challenging. There are many different perturbations that can alter the optical properties, including charge doping, defects, strain, oxidation, and water intercalation. Identifying which perturbations are present is usually not straightforward and …
Converting earth-abundant dinitrogen into value-added chemical ammonia is a significant yet challenging topic. Electrocatalytic nitrogen reduction reaction (NRR), compared with conventional Haber-Bosch process, is an energy-saving and environmentally friendly approach. The major task of electrocatalytic NRR is to find electrocatalysts which can activate dinitrogen effectively and exhibit high selectivity and stability. Single atom catalysts can act as a good solution. In this work, by means of first-principles density functional theory, molecular dynamics calculations, and a two-step screening…
Using a dual plasma process to produce cobalt--polypyrrole catalysts for the oxygen reduction reaction in fuel cells -- part II: analysing the chemical structure of the films
Novel photoelectrocatalysts that use sunlight to power the CO$_2$ reduction reaction will be crucial for carbon-neutral power and energy-efficient industrial processes. Scalable photoelectrocatalysts must satisfy a stringent set of criteria, such as stability under operating conditions, product selectivity, and efficient light absorption. Two-dimensional materials can offer high specific surface area, tunability, and potential for heterostructuring, providing a fresh landscape of candidate catalysts. From a set of promising bulk CO$_2$ reduction photoelectrocatalysts, we screen for candidate m…
