Electrospun Iridium-Based Nanofiber Catalysts for Oxygen Evolution Reaction: Influence of Calcination on Activity-Stability Relation.

The enhanced utilization of noble metal catalysts through highly porous nanostructures is crucial to advancing the commercialization prospects of proton exchange membrane water electrolysis (PEMWE). In this study, hierarchically structured IrO-based nanofiber catalyst materials for acidic water electrolysis are synthesized by electrospinning, a process known for its scalability and ease of operation. A calcination study at various temperatures from 400 to 800 °C is employed to find the best candidates for both electrocatalytic activity and stability.

Detecting Early-Stage Cohesion Due to Calcium Silicate Hydration with Rheology and Surface Force Apparatus.

Extremely robust cohesion triggered by calcium silicate hydrate (C-S-H) precipitation during cement hardening makes concrete one of the most commonly used man-made materials. Here, in this proof-of-concept study, we seek an additional nanoscale understanding of early-stage cohesive forces acting between hydrating model tricalcium silicate (CS) surfaces by combining rheological and surface force measurements. We first used time-resolved small oscillatory rheology measurements (SAOSs) to characterize the early-stage evolution of the cohesive properties of a CS paste and a C-S-H gel.

Visualization of Ion|Surface Binding and In Situ Evaluation of Surface Interaction Free Energies via Competitive Adsorption Isotherms.

Function and properties at biologic as well as technological interfaces are controlled by a complex and concerted competition of specific and unspecific binding with ions and water in the electrolyte. It is not possible to date to directly estimate by experiment the interfacial binding energies of involved species in a consistent approach, thus limiting our understanding of how interactions in complex (physiologic) media are moderated. Here, we employ a model system utilizing polymers with end grafted amines interacting with a negatively charged mica surface.

Photocorrosion of ZnO Single Crystals during Electrochemical Water Splitting.

Degradation and dissolution of transparent semiconducting oxides is central to various areas, including design of catalysts and catalysis conditions, as well as passivation of metal surfaces. In particular, photocorrosion can be significant and plays a central role during photoelectrochemical activity of transparent semiconducting oxides. Here, we utilize an electrochemical flow cell combined with an inductively coupled plasma mass spectrometer (ICP-MS) to enable the in situ study of the time-resolved release of zinc into solution under simultaneous radiation of UV-light.

Adsorption and Diffusion Moderated by Polycationic Polymers during Electrodeposition of Zinc.

Electrodeposition of metals is relevant to much of materials research including catalysis, batteries, antifouling, and anticorrosion coatings. The sacrificial characteristics of zinc used as a protection for ferrous substrates is a central corrosion protection strategy used in automotive, aviation, and DIY industries. Zinc layers are often used for protection by application to a base metal in a hot dip galvanizing step; however, there is a significant interest in less energy and material intense electroplating strategies for zinc.