The fabrication of three-dimensional assemblies consisting of large quantities of nanowires is of great technological importance for various applications including (electro-)catalysis, sensitive sensing, and improvement of electronic devices. Because the spatial distribution of the nanostructured material can strongly influence the properties, architectural design is required in order to use assembled nanowires to their full potential. In addition, special effort has to be dedicated to the development of efficient methods that allow precise control over structural parameters of the nanoscale building blocks as a means of tuning their characteristics. This paper reports the direct synthesis of highly ordered large-area nanowire networks by a method based on hard templates using electrodeposition within nanochannels of ion track-etched polymer membranes. Control over the complexity of the networks and the dimensions of the integrated nanostructures are achieved by a modified template fabrication. The networks possess high surface area and excellent transport properties, turning them into a promising electrocatalyst material as demonstrated by cyclic voltammetry studies on platinum nanowire networks catalyzing methanol oxidation. Our method opens up a new general route for interconnecting nanowires to stable macroscopic network structures of very high integration level that allow easy handling of nanowires while maintaining their connectivity.

Porphyrin-based metal–organic frameworks (MOFs), exemplified by MOF-525, PCN-221, and PCN-224, are promising systems for catalysis, optoelectronics, and solar energy conversion. However, subtle differences between synthetic protocols for these three MOFs give rise to vast discrepancies in purported product outcomes and description of framework topologies. Here, based on a comprehensive synthetic and structural analysis spanning local and long-range length scales, we show that PCN-221 consists of Zr6O4(OH)4 clusters in four distinct orientations within the unit cell, rather than Zr8O6 clusters as originally published, and linker vacancies at levels of around 50%, which may form in a locally correlated manner. We propose disordered PCN-224 (dPCN-224) as a unified model to understand PCN-221, MOF-525, and PCN-224 by varying the degree of orientational cluster disorder, linker conformation and vacancies, and cluster–linker binding. Our work thus introduces a new perspective on network topology and disorder in Zr-MOFs and pinpoints the structural variables that direct their functional properties.

Operando X-ray absorption spectroscopy (XAS) has been used to study the adsorbates and structural changes and their dependence on potential, existing during the ethanol oxidation reaction (EOR) on carbon-supported Pt, PtRu, and PtSn anode catalysts. Conventional EXAFS was applied to identify nanoparticle structure and particle size. The ∆µ-XANES technique was used to investigate adsorbed species with potential. On pure Pt, an overall increase in ∆µ amplitude exists under EOR compared to that existing during the methanol oxidation reaction (MOR). This increased amplitude was attributed mainly to the C 1 species on the surface during the EOR; these C 1 species and CO become oxidized when O(H) come down on the surface. On PtRu catalysts, the O(H) formation and C-species oxidation begins at lower potentials compared to Pt. The ligand effect from oxidized RuO x islands is operative in PtRu and responsible for the performance enhancement. On PtSn, we observe O(H) at nearly all potentials, which may be explained by a very strong ligand effect involving SnO x . The operando ∆µ and EXAFS results enable the determination of relative active surface areas, particle structure, and adsorbate coverages with potential of C species, OH, and O providing new insights into the role of OH in the EOR.