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Metallic nanoparticles are widely explored for boosting light-matter coupling, optoelectronic response, and improving photocatalytic performance of two-dimensional (2D) materials. However, the target area is restricted to either top or bottom of the 2D flakes. Here, we introduce an approach for edge-specific nanoparticle decoration via light-assisted reduction of silver ions and merging of silver seeds. We observe arrays of the self-limited in size silver nanoparticles along tungsten diselenide WSe2 nanoribbon edges. The density of nanoparticles is tunable by adjusting the laser fluence. Scanning electron microscopy, atomic force microscopy, and Raman spectroscopy are used to investigate the size, distribution, and photo-response of the deposited plasmonic nanoparticles on the quasi-one-dimensional nanoribbons. We report an on-surface synthesis path for creating mixed-dimensional heterostructures and heterojunctions with potential applications in opto-electronics, plasmonics, and catalysis, offering improved light matter coupling, optoelectronics response, and photocatalytic performance of 2D materials.

There is evidence from the near‐infrared observations of space missions of the presence of carbonates on the surface of several ocean worlds. However, their genesis remains unresolved. We investigate the hypothesis that these carbonates may be in the form of clathrites assuming that clathrate hydrates are stable phases in the crust and ocean of these ocean worlds. In order to support this, we studied a sample of a potential clathrite from the Hydrate Ridge cold seep (Cascadia Subduction Zone), the carbonate rock fossil of clathrate hydrates, as a terrestrial analogue. We characterised the mineralogy and texture of the sample by using a coupled confocal Raman microscope and scanning electron microscopy instrument with the aim of identifying possible geo‐ and biosignatures, which could be relevant for future missions of exploration to ocean worlds and Mars. Our results show that aragonite is the dominant mineral phase in the clathrite sample, but Mg‐calcite and dolomite were also identified. These three carbonates constitute a pattern related to clathrate hydrate formation and dissociation processes. Dolomite was defined as a biosignature of gas hydrate microbiomes because it was integrated within Mg‐calcite grains precipitated after clathrate hydrate dissociation. Nevertheless, no spectral changes were observed in Raman bands of carbonate minerals that would indicate the influence of clathrate hydrates in their genesis. We also observed that Raman band positions of the associated framboidal pyrites are a characteristic signature of the associated framboid‐like texture because its potential as biosignature may only be attributed by biochemical analysis. [ABSTRACT FROM AUTHOR]

Electrodepositing insulating lithium peroxide (Li2O2) is the key process during discharge of aprotic Li-O2 batteries and determines rate, capacity, and reversibility. Current understanding states that the partition between surface adsorbed and dissolved lithium superoxide governs whether Li2O2 grows as a conformal surface film or larger particles, leading to low or high capacities, respectively. However, better understanding governing factors for Li2O2 packing density and capacity requires structural sensitive in situ metrologies. Here, we establish in situ small- and wide-angle X-ray scattering (SAXS/WAXS) as a suitable method to record the Li2O2 phase evolution with atomic to submicrometer resolution during cycling a custom-built in situ Li-O2 cell. Combined with sophisticated data analysis, SAXS allows retrieving rich quantitative structural information from complex multiphase systems. Surprisingly, we find that features are absent that would point at a Li2O2 surface film formed via two consecutive electron transfers, even in poorly solvating electrolytes thought to be prototypical for surface growth. All scattering data can be modeled by stacks of thin Li2O2 platelets potentially forming large toroidal particles. Li2O2 solution growth is further justified by rotating ring-disk electrode measurements and electron microscopy. Higher discharge overpotentials lead to smaller Li2O2 particles, but there is no transition to an electronically passivating, conformal Li2O2 coating. Hence, mass transport of reactive species rather than electronic transport through a Li2O2 film limits the discharge capacity. Provided that species mobilities and carbon surface areas are high, this allows for high discharge capacities even in weakly solvating electrolytes. The currently accepted Li-O2 reaction mechanism ought to be reconsidered. [ABSTRACT FROM AUTHOR]

The corrosion resistance of the steel grades 1.4509 and 1.4301 against sodium and calcium chloride, at 650 and 750 °C is investigated by means of cyclic exposure tests (CETs) in dry air. The formation of chromates as well as volatile metal chlorides and oxychlorides leads to non‐protective oxide scales on both steel grades. At 650 and 750 °C and in presence of a salt layer the alloy 1.4301 shows a higher corrosion resistance than the material 1.4509. At 750 °C and in presence of salt, the surface of the steel grade 1.4301 is transformed from a face centered cubic (fcc) to a body centered cubic (bcc) lattice, due to corrosion induced de‐alloying. The surfaces of both tested materials deplete in chromium, especially at 750 °C. Consequently, the corrosion resistance of the materials exposed to CET decreases sharply in aqueous corrodants. [ABSTRACT FROM AUTHOR]

Enzyme‐modified electrodes are core components of electrochemical biosensors for diagnostic and environmental analytics and have promising applications in bioelectrocatalysis. Despite huge research efforts spanning decades, design of enzyme electrodes for superior performance remains challenging. Nanoporous gold (npAu) represents advanced electrode material due to high surface‐to‐volume ratio, tunable porosity, and intrinsic redox activity, yet its coupling with enzyme catalysis is complex. Here, the study reports a flexible‐modular approach to modify npAu with functional enzymes by combined material and protein engineering and use a tailored assortment of surface and in‐solution methodologies for characterization. Self‐assembled monolayer (SAM) of mercaptoethanesulfonic acid primes the npAu surface for electrostatic adsorption of the target enzyme (flavocytochrome P450 BM3; CYT102A1) that is specially equipped with a cationic protein module for directed binding to anionic surfaces. Modulation of the SAM surface charge is achieved by electrochemistry. The electrode‐adsorbed enzyme retains well the activity (33%) and selectivity (complete) from in‐solution. Electrochemically triggered nanoscale stirring in the internal porous network of npAu‐SAM enhances speed (2.5‐fold) and yield (3.0‐fold) of the enzyme immobilization. Biocatalytic reaction is fueled from the electrode via regeneration of its reduced coenzyme (NADPH). Collectively, the study presents a modular design of npAu‐based enzyme electrode that can support flexible bioelectrochemistry applications. [ABSTRACT FROM AUTHOR]