Efficiency and selectivity of electrochemical reactions is controlled by the micro-environments within the electric double layer (EDL) forming the electrode-electrolyte interface. In electrocatalysis, additives can direct interfacial structure, enhancing activities....

High-entropy alloy nanoparticles (HEA NPs) constitute an interesting material class with high potential as heterogeneous catalysts due to their exceptional compositional and structural tunability and the complex interplay of different element-specific surface sites. Laser ablation in liquids (LAL) is a kinetically controlled synthesis method that allows the generation of colloidal HEA NPs. With CrMnFeCoNi-NPs, a facile control of the NP phase structure, switching between crystalline and amorphous via applied laser pulse duration, has been previously reported, attributed to the different particle solidification times and metalloidic carbon incorporation pathways. However, neither the replacement of the oxygen-affine Mn by the sp2-carbon coupling element Cu, nor the transferability of the pulsed laser fabrication process from bulk target to micropowder feedstock processing, has been studied. In the present work, we use scanning transmission electron microscopy, equipped with energy-dispersive X-ray spectroscopy (STEM-EDX), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), and X-ray diffraction (XRD) to demonstrate the transferability of internal phase structure tunability to the CrFeCoNiCu alloy and confirm ns- and ps-pulsed LAL yielding amorphous and crystalline HEA NPs, respectively, with diameters of 10-40 nm. Furthermore, we examine the generation of CrMnFeCoNi and CrFeCoNiCu nanoparticles by scalable, fully continuous ns-pulsed microparticle laser fragmentation in liquid (MP-LFL) using a high-power UV-laser and find the emergence of amorphous phase structures only in the Cu-containing nanoparticles, a phenomenon we attribute to copper-catalyzed carbon incorporation into the HEA NPs. These studies are complemented by a detailed characterization of the surface electrochemistry of the HEA NPs via alkaline cyclic voltammetry (CV) and elemental compositions in surface-near volumes, quantified by X-ray photoelectron spectroscopy (XPS). We elucidate that primarily the chemical composition (Mn vs. Cu) and, only to a lower extent, the phase structure (amorphous vs. crystalline) determine the surface potential, electrochemical stability upon multiple CV cycling, and surface element distribution of the particles. Finally, the activity of the HEA NPs in the oxygen evolution reaction (OER) is evaluated via linear sweep voltammetry (LSV), where we find amorphous CrMnFeCoNi HEA NPs to be more active (lower overpotential, higher current density) than their crystalline counterparts, motivating future application-focused work and transfer to other material systems and relevant reactions.

Sum frequency generation (SFG) spectroscopy was applied to investigate D₂O adsorption on atomic layer deposition (ALD)–grown Al₂O₃, ZrO₂, and TiO₂ films at 94 ± 1 K. Film composition and thickness...

Resonant catalysis theory predicts that applying an intermittent stimulus, such as charge, strain, heat or light, at frequencies on the timescale higher than the catalytic turnover frequency, can enhance activity...

Creating and curating new data to augment heuristics is a forthcoming approach to materials science in the future. Highly improved properties are advantageous even with "commodity polymers" that do not need to undergo new synthesis, high-temperature processes, or extensive reformulation. With artificial intelligence and machine learning (AI/ML), optimizing synthesis and manufacturing methods will enable higher throughput and innovative directed experiments. Simulation and modeling to create digital twins with statistical and logic-derived design, such as the design of experiments (DOE), will be superior to trial-and-error approaches when working with polymer materials. This paper describes and demonstrates protocols for understanding hierarchical approaches in optimizing the polymerization and copolymerization process via AI/ML to target specific properties, using model monomers such as styrene and acrylate. The key is self-driving continuous flow chemistry reactors with sensors (instruments) and real-time ML with an online monitoring set-up that allows a feedback loop mechanism. We provide initial results using ML refinement of the classical Mayo-Lewis equation (MLE), time-series data, and an autonomous flow reactor system build-up as a future data-generating station. More importantly, it lays the ground for precision control of the copolymerization process. In the future, it should be possible to undertake collaborative human-AI-guided protocols for the autonomous fabrication of new polymers guided by literature and available data sources targeting new properties.

Crystallization-driven self-assembly (CDSA) offers a powerful approach for constructing well-defined nanostructures; however, achieving precise control over two-dimensional (2D) platelet formation remains challenging, particularly for poly(L-lactide) (PLLA). In this work, we developed a seeded growth strategy using a mixture of homopolymers and diblock polymers to prepare PLLA platelets. In this system, homopolymers facilitate the formation of 2D platelets and enhance crystallization kinetics, while diblock polymers stabilize the platelets and provide functional moieties through their corona-forming block. By systematically optimizing temperature, polymer composition, and polymer length, we achieved size-controllable platelets. Furthermore, we successfully transferred the platelet preparation from batch to a continuous flow system to enable scalable production. This study contributes to the advancement of biodegradable and biocompatible nanoparticles, offering new possibilities for their application in biomedical and functional materials.

Driven by the persisting poor understanding of the electrocatalytic hydrogen evolution reaction (HER) in alkaline medium, we studied the interfacial water structure at a polycrystalline Au surface using a combination...