Uncovering local structural motif in nanomaterials is essential because atomic arrangements on the very local scale may have significant impact on the material properties. Furthermore, understanding synthesis-structure relations is crucial for rational design processes of novel nanocompounds. Total scattering experiments with Pair Distribution Function (PDF) analysis has proven itself as a powerful tool for studying short-range order of inorganic compounds. By applying PDF methods in time-resolved studies, insights into material formation and structural changes can be obtained. Thereby, a range of processes, e.g., syntheses and electrochemical systems, can be carefully investigated.

In the studies presented here, transition metal (Nb, W, Hf, and Ni, Fe, Co) oxides and hydroxides have been synthesized by applying simple solvothermal syntheses approaches. Preceding studies revealed that a variety of transition metal oxides show promising properties for energy-storage solutions. However, this thesis focuses on providing a finer understanding of the local structural motifs and synthesis-structure relations.

First, X-ray total scattering with subsequent PDF analysis was used to study the structure of a size-series of niobium oxide nanoparticles. The studies revealed that the local structure differs from the average global structure. The formation pathway of niobium oxide nanoparticles from NbCl5 in benzyl alcohol was further investigated through in situ PDF studies. Niobium oxide nanoparticles form from single [NbClxO6-x] octahedra, which grow into larger clusters of corner-sharing networks of [NbO6] octahedra. Analysis of the nanoparticle growth showed that extended defects evolved during the growth process.
Using a Pearson Correlation Coefficient (PCC) approach, additional experiments on niobium oxide formation with varying solvents were examined. PCC analysis was used to automate the structure database search for structural solutions, and to quantitively show, how the structure of small niobium oxide nanoparticles is challenging to distinguish with PDF analysis. Using operando X-ray total scattering, local structural changes in the niobium oxide nanoparticles during electrochemically Li-ion insertion were suggested. In perspective of the niobium oxide system, formation of tungsten and hafnium oxides were investigated under comparable synthesis conditions, revealing similar pathways.

Spinel cobalt iron oxide nanoparticles were synthesized through a solvothermal synthesis approach. The synthesized nanoparticles characteristics were thoroughly examined using X-ray total scattering and PDF analysis, microscopy, spectroscopy, and neutron scattering experiments. The choice of solvent in the syntheses (water or tert-butanol) had a direct influence on the crystallite size of the formed nanoparticles. It was found that the smallest nanoparticles (2 nm) had a higher iron content on the tetrahedral sites, enlarged ADP values and a more contracted lattice, which was attributed to oxidation of the small particles.

X-ray total scattering studies were also used to investigate the structure of hydrothermally synthesized nickel iron layered double hydroxides (LDH). The effects of varying the Ni:Fe ratios were investigated, showing that with a 1:1 ratio, a spinel phase forms alongside the LDH phase. PDF analysis further demonstrated that the layered material resembled turbostratic disorder.

Lastly, the structure of NiFe-LDH material was investigated under oxygen evolution reaction (OER) conditions using operando X-ray total scattering. Here, structural changes were observed under OER potentials. Contractions of both inter- and intralayer distances and a non-reversible crystallite size decrease were observed.