Uncovering the Network Modifier for Highly Disordered Amorphous Li-Garnet Glass-Ceramics.

Highly disordered amorphous LiLaZrO (aLLZO) is a promising class of electrolyte separators and protective layers for hybrid or all-solid-state batteries due to its grain-boundary-free nature and wide electrochemical stability window. Unlike low-entropy ionic glasses such as LiPON (LiPON), these medium-entropy non-Zachariasen aLLZO phases offer a higher number of stable structure arrangements over a wide range of tunable synthesis temperatures, providing the potential to tune the LBU-Li transport relation. It is revealed that lanthanum is the active "network modifier" for this new class of highly disordered Li conductors, whereas zirconium and lithium serve as "network formers".

Thermal Stability of Au Rhombic Dodecahedral Nanocrystals Can Be Greatly Enhanced by Coating Their Surface with an Ultrathin Shell of Pt.

Rhombic dodecahedral nanocrystals have been considered particularly difficult to synthesize because they are enclosed by {110}, a low-index facet with the greatest surface energy. Recently, we demonstrated the use of seed-mediated growth for the facile and robust synthesis of Au rhombic dodecahedral nanocrystals (AuRD). While the unique shape and surface structure of AuRD are desirable for potential applications in plasmonics and catalysis, respectively, their high surface energy makes them highly susceptible to thermal degradation.

Single-Atom Catalysts for Selective Oxygen Reduction: Transition Metals in Uniform Carbon Nanospheres with High Loadings.

Transition metal single-atom catalysts (SACs) in uniform carbon nanospheres have gained tremendous interest as electrocatalysts owing to their low cost, high activity, and excellent selectivity. However, their preparation typically involves complicated multistep processes that are not practical for industrial use. Herein, we report a facile one-pot method to produce atomically isolated metal atoms with high loadings in uniform carbon nanospheres without any templates or postsynthesis modifications.

Multifunctional Coatings on Sulfide-Based Solid Electrolyte Powders with Enhanced Processability, Stability, and Performance for Solid-State Batteries.

Sulfide-based solid-state electrolytes (SSEs) exhibit many tantalizing properties including high ionic conductivity and favorable mechanical properties for next-generation solid-state batteries. Widespread adoption of these materials is hindered by their intrinsic instability under ambient conditions, which makes them difficult to process at scale, and instability at the Li||SSE and cathode||SSE interfaces, which limits cell performance and lifetime. Atomic layer deposition is leveraged to grow thin Al O coatings on Li PS Cl powders to address both issues simultaneously.

Design of Atomic Ordering in MoNbCT MXenes for Hydrogen Evolution Electrocatalysis.

The need for novel materials for energy storage and generation calls for chemical control at the atomic scale in nanomaterials. Ordered double-transition-metal MXenes expanded the chemical diversity of the family of atomically layered 2D materials since their discovery in 2015. However, atomistic tunability of ordered MXenes to achieve ideal composition-property relationships has not been yet possible.

Chiral assemblies of pinwheel superlattices on substrates.

The unique topology and physics of chiral superlattices make their self-assembly from nanoparticles highly sought after yet challenging in regard to (meta)materials. Here we show that tetrahedral gold nanoparticles can transform from a perovskite-like, low-density phase with corner-to-corner connections into pinwheel assemblies with corner-to-edge connections and denser packing. Whereas corner-sharing assemblies are achiral, pinwheel superlattices become strongly mirror asymmetric on solid substrates as demonstrated by chirality measures.

High-Entropy 2D Carbide MXenes: TiVNbMoC and TiVCrMoC.

Two-dimensional (2D) transition metal carbides and nitrides, known as MXenes, are a fast-growing family of 2D materials. MXenes 2D flakes have + 1 ( = 1-4) atomic layers of transition metals interleaved by carbon/nitrogen layers, but to-date remain limited in composition to one or two transition metals. In this study, by implementing four transition metals, we report the synthesis of multi-principal-element high-entropy MCT MXenes.

Atomistic insights into the nucleation and growth of platinum on palladium nanocrystals.

Despite the large number of reports on colloidal nanocrystals, very little is known about the mechanistic details in terms of nucleation and growth at the atomistic level. Taking bimetallic core-shell nanocrystals as an example, here we integrate in situ liquid-cell transmission electron microscopy with first-principles calculations to shed light on the atomistic details involved in the nucleation and growth of Pt on Pd cubic seeds. We elucidate the roles played by key synthesis parameters, including capping agent and precursor concentration, in controlling the nucleation site, diffusion path, and growth pattern of the Pt atoms.

Local electronic structure variation resulting in Li 'filament' formation within solid electrolytes.

Solid electrolytes hold great promise for enabling the use of Li metal anodes. The main problem is that during cycling, Li can infiltrate along grain boundaries and cause short circuits, resulting in potentially catastrophic battery failure. At present, this phenomenon is not well understood.

Kinetically Controlled Synthesis of Rhodium Nanocrystals with Different Shapes and a Comparison Study of Their Thermal and Catalytic Properties.

We report the synthesis of Rh nanocrystals with different shapes by controlling the kinetics involved in the growth of preformed Rh cubic seeds. Specifically, Rh nanocrystals with cubic, cuboctahedral, and octahedral shapes can all be obtained from the same cubic seeds under suitable reduction kinetics for the precursor. The success of such a synthesis also relies on the use of a halide-free precursor to avoid oxidative etching, as well as the involvement of a sufficiently high temperature to remove Br ions from the seeds while ensuring adequate surface diffusion.

Elucidating Interfacial Stability between Lithium Metal Anode and Li Phosphorus Oxynitride via Electron Microscopy.

Li phosphorus oxynitride (LiPON) is one of a very few solid electrolytes that have demonstrated high stability against Li metal and extended cyclability with high Coulombic efficiency for all solid-state batteries (ASSBs). However, theoretical calculations show that LiPON reacts with Li metal. Here, we utilize electron microscopy to observe the dynamic evolutions at the LiPON-Li interface upon contacting and under biasing.

Toward Controlling Filament Size and Location for Resistive Switches via Nanoparticle Exsolution at Oxide Interfaces.

Memristive devices are among the most prominent candidates for future computer memory storage and neuromorphic computing. Though promising, the major hurdle for their industrial fabrication is their device-to-device and cycle-to-cycle variability. These occur due to the random nature of nanoionic conductive filaments, whose rupture and formation govern device operation.

Scalable neutral HO electrosynthesis by platinum diphosphide nanocrystals by regulating oxygen reduction reaction pathways.

Despite progress in small scale electrocatalytic production of hydrogen peroxide (HO) using a rotating ring-disk electrode, further work is needed to develop a non-toxic, selective, and stable O-to-HO electrocatalyst for realizing continuous on-site production of neutral hydrogen peroxide. We report ultrasmall and monodisperse colloidal PtP nanocrystals that achieve HO production at near zero-overpotential with near unity HO selectivity at 0.27 V vs.

Oxygen Exchange in Dual-Phase LaSrMnO-CeO Composites for Solar Thermochemical Fuel Production.

Increasing the capacity and kinetics of oxygen exchange in solid oxides is important to improve the performance of numerous energy-related materials, especially those for the solar-to-fuel technology. Dual-phase metal oxide composites of LaSrMnO-%CeO, with = 0, 5, 10, 20, 50, and 100, have been experimentally investigated for oxygen exchange and CO splitting thermochemical redox reactions. The prepared metal oxide powders were tested in a temperature range from 1000 to 1400 °C under isothermal and two-step cycling conditions relevant for solar thermochemical fuel production.

Lithium-Battery Anode Gains Additional Functionality for Neuromorphic Computing through Metal-Insulator Phase Separation.

Specialized hardware for neural networks requires materials with tunable symmetry, retention, and speed at low power consumption. The study proposes lithium titanates, originally developed as Li-ion battery anode materials, as promising candidates for memristive-based neuromorphic computing hardware. By using ex- and in operando spectroscopy to monitor the lithium filling and emptying of structural positions during electrochemical measurements, the study also investigates the controlled formation of a metallic phase (Li Ti O ) percolating through an insulating medium (Li Ti O ) with no volume changes under voltage bias, thereby controlling the spatially averaged conductivity of the film device.

Colloidal silver diphosphide (AgP) nanocrystals as low overpotential catalysts for CO reduction to tunable syngas.

Production of syngas with tunable CO/H ratio from renewable resources is an ideal way to provide a carbon-neutral feedstock for liquid fuel production. Ag is a benchmark electrocatalysts for CO-to-CO conversion but high overpotential limits the efficiency. We synthesize AgP nanocrystals (NCs) with a greater than 3-fold reduction in overpotential for electrochemical CO-to-CO reduction compared to Ag and greatly enhanced stability.

Synthesis of CaO Nanocrystals and Their Spherical Aggregates with Uniform Sizes for Use as a Biodegradable Bacteriostatic Agent.

As a solid precursor to O and hydrogen peroxide (H O ), calcium peroxide (CaO ) has found widespread use in applications related to disinfection and contaminant degradation. The lack of uniform nanoparticles, however, greatly limits the potential use of this material in other applications related to medicine. Here, a new route to the facile synthesis of CaO nanocrystals and their spherical aggregates with uniform, controllable sizes is reported.

Ruthenium Nanoframes in the Face-Centered Cubic Phase: Facile Synthesis and Their Enhanced Catalytic Performance.

Owing to their highly open structure and a large number of low-coordination sites on the surface, noble-metal nanoframes are intriguing for catalytic applications. Here, we demonstrate the rational synthesis of Ru cuboctahedral nanoframes with enhanced catalytic performance toward hydrazine decomposition. The synthesis starts from Pd nanocubes, which quickly undergo truncation at the corners as a consequence of oxidative etching caused by Br ions.

Reversibly tuning the surface state of Ag via the assistance of photocatalysis in Ag/BiOCl.

Silver (Ag) nanoparticles can be spontaneously oxidized and present in different oxidized surface phases. The impact of oxidation induced photo absorption property and related photocatalytic activity are still unclear in Ag-decorated semiconductor photocatalysts. Herein, Ag-decorated BiOCl with the metallic Ag to oxidized Ag were employed to investigate the effect of surface state of Ag on relative photocatalyst properties.

Ru Octahedral Nanocrystals with a Face-Centered Cubic Structure, {111} Facets, Thermal Stability up to 400 °C, and Enhanced Catalytic Activity.

Ruthenium nanocrystals with both a face-centered cubic ( fcc) structure and well-controlled facets are attractive catalytic materials for various reactions. Here we report a simple method for the synthesis of Ru octahedral nanocrystals with an fcc structure and an edge length of 9 nm. The success of this synthesis relies on the use of 4.

2D/2D heterojunction of TiC/g-CN nanosheets for enhanced photocatalytic hydrogen evolution.

Photocatalytic hydrogen evolution from water has received enormous attention due to its ability to address a number of global environmental and energy-related issues. Here, we synthesize 2D/2D Ti3C2/g-C3N4 composites by electrostatic self-assembly technique and demonstrate their use as photocatalysts for hydrogen evolution under visible light irradiation. The optimized Ti3C2/g-C3N4 composite exhibited a 10 times higher photocatalytic hydrogen evolution performance (72.

Photothermal transformation of Au-Ag nanocages under pulsed laser irradiation.

Pulsed laser irradiation has emerged as an effective means to photothermally transform plasmonic nanostructures after their use in different biomedical applications. However, the ability to predict the products after photothermal transformation requires extensive ex situ studies. Here, we report a systematic study of the photothermal transformation of Au-Ag nanocages with a localized surface plasmon resonance at ca.