Prussian blue (PB) and its analogs (PBAs) are interesting materials for electrochemical applications due to their tunable redox chemistry and open framework structure. In this study, hexacyanoferrates (HCF) containing iron (FeHCF), cobalt (CoHCF), and nickel (NiHCF) were synthesized via potentiostatic electrodeposition. Cyclic voltammetry revealed distinct redox behaviors. Morphological characterization (SEM, EDX) demonstrated uniform, pyramidal film growth for FeHCF and CoHCF. Otherwise, NiHCF presented a cracked film with cubic clusters on top due to residual stress. Despite this, homogeneous element distribution was found for all samples. Structural characterization (TEM and XRD) confirmed a cubic lattice crystal structure for all films, with systematic lattice contraction from Fe to Co to Ni due to decreasing atomic radius. Raman and XPS data revealed a shift toward Fe²⁺ dominant oxidation states and modifications in C≡N bonding, with the influence of K⁺ and water occupancy in the PBAs framework. These findings illustrate how metal substitution and deposition parameters can tune the structural and electrochemical properties of PBA films, presenting a strategic route to design tailored electrodes.

Understanding how electrolyte composition influences the structural factors governing charge storage in Prussian Blue analogues (PBAs) requires disentangling the coupled effects of ion desolvation, structural disorder, and transport pathway connectivity. Here, we demonstrate that electrolyte identity induces structural disorder, which correlates with transport dispersion observed under identical electrochemical conditions. To establish this relationship, Fe-, Co-, and Ni-based hexacyanoferrate thin films were electrodeposited in chloride electrolytes (KCl, NaCl, NH$4Cl, and LiCl), enabling a comparative investigation of structure--transport correlations across multiple length scales.While all systems crystallize in the cubic PBAs structure, pronounced electrolyte-dependent variations in lattice parameter, defect density, and local coordination environment are observed. Na+ induces lattice expansion but simultaneously promotes vacancy formation, microstrain, and structural heterogeneity, whereas K+ and NH4+ yield more coherent frameworks with reduced disorder. Raman spectroscopy reveals that increasing structural disorder broadens the distribution of local coordination environments, which directly translates into a distributed electrochemical response.Electrochemical impedance spectroscopy reveals that charge storage is governed by coupled ion--electron transport processes, with impedance increasing by more than one order of magnitude from FeHCF to NiHCF. Importantly, the constant phase element (CPE) exponent systematically decreases with increasing Raman band broadening, revealing a strong correlation between structural disorder and transport dispersion.These results demonstrate that electrolyte identity controls not only lattice dimensions but, more critically, the topology and connectivity of defect networks. Optimal electrochemical performance therefore arises from a balance between structural coherence and accessible transport pathways, rather than lattice expansion alone.

Assemblies of plasmonic nanoparticles (NPs) support hybridized modes of localized surface plasmons (LSPs), which delocalize in geometrically well-ordered arrangements. Here, the hybridization behavior of LSPs in geometrically completely disordered two-dimensional arrangements of Au NPs fabricated by an e-beam synthesis method is studied. Employing electron energy loss spectroscopy in a scanning transmission electron microscope and numerical simulations, the disorder-driven spatial and spectral localization of the coupled LSP modes that depends on the NP thickness is revealed. Below a NP thickness of 0.4 nm, localization increases toward higher hybridized LSP mode energies. In comparison, above 10 nm thickness, a decrease of localization toward higher mode energies is observed. In the intermediate thickness regime, a transition of the energy dependence of the localization between the two limiting cases, exhibiting a mode energy with minimal localization, is observed. It is shown that this behavior is mainly driven by the energy and thickness dependence of the polarizability of the individual NPs.