Structural Evolution of Ammonium Paratungstate During Thermal Decomposition

In der Arbeit werden Untersuchungen an Ammoniumparafolframat (APW)vorgestellt. Die Zersetzung von APW wurde mittels in situ XAS, in situ XRD und TG/DSC untersucht. Während der thermischen Zersetzung von APW finden die hauptsächlichen Veränderungen bei ungefähr 500 K statt, verbunden mit kompletter Strukturreorganisation.In this work investigations on ammonium paratungstate (APT) are presented. The decomposition of APT was elucidated by the comlementary techniques in situ XAS, in situ XRD, and TG/DSC. During the thermal treatment of APT, major changes occur at 500 K where a complete structural rearrangement takes place

Pt and Pd Nanoparticle Crystallization in the Sol-Gel-Derived Thin SiO₂ Films

The crystallization and distribution the features of Pt, Pd and Pt/Pd nanoparticles in spin-on glass SiO2 films were studied within a wide range of the dopant concentrations in silica sol (from 10 to 80 mol.% Pt, Pd or Pt/Pd per 100 mol.% Si). The grazing incidence X-ray diffraction (GIXRD) characterization revealed that the formation of 4–8 nm sized crystalline Pt, Pd and Pt/Pd nanoparticles in SiO2 films began at the dopant concentrations of at least 10 mol.% Pt and/or Pd per 100 mol.% Si. The nanoparticles obtained from sols with the lower Pt, Pd or Pt/Pd concentrations were characterized by an amorphous structure. The dopants distribution over the film thickness (~21–47 nm) was studied using X-ray reflectometry. The effect of the dopant concentration, spin-coating modes and heat treatment temperature on the film thickness was characterized. When only one of the dopants (Pt or Pd) was introduced into the silica sol, the resulting nanoparticles were preferentially localized close to the film surface. When dopants were used together, the Pt/Pd nanoparticles were distributed more evenly

Aminated Graphene Nanomesh: Theoretical and Experimental Insights into Process of Decorating, Topology and Electron Properties

The physicochemical nature of the amino group NH2’s landing on the basal plane of the graphene and on the edge atoms of the graphene nanomesh was revealed. The mechanism of covalent binding between the NH2 groups and the carbon atoms of the graphene and the GNM was discovered in silico by the SCC DFTB method. The maximum amount ratio of the amino groups to carbon atoms equaled 4.8% for GNM and 4.6% for the basal plane. The established values of the concentration and the trend of change in the work function of electrons are experimentally confirmed

Aminated Graphene Nanomesh: Theoretical and Experimental Insights into Process of Decorating, Topology and Electron Properties

The physicochemical nature of the amino group NH2’s landing on the basal plane of the graphene and on the edge atoms of the graphene nanomesh was revealed. The mechanism of covalent binding between the NH2 groups and the carbon atoms of the graphene and the GNM was discovered in silico by the SCC DFTB method. The maximum amount ratio of the amino groups to carbon atoms equaled 4.8% for GNM and 4.6% for the basal plane. The established values of the concentration and the trend of change in the work function of electrons are experimentally confirmed