Tuning the selectivity of bimetallic Cu electrocatalysts for CO reduction using atomic layer deposition.

Cu-Zn bimetallic catalysts were synthesized on 3-D gas diffusion electrodes using atomic layer deposition (ALD) techniques. Electrochemical CO reduction was evaluated, and a significant variation in the product selectivity was observed compared to unmodified Cu catalysts. As low as a single ALD cycle of ZnO resulted in a reduction of CH production and shift towards CO selectivity, which is attributed to changes in the chemical state of the surface.

Eliminating chemo-mechanical degradation of lithium solid-state battery cathodes during >4.5 V cycling using amorphous NbO coatings.

Lithium solid-state batteries offer improved safety and energy density. However, the limited stability of solid electrolytes (SEs), as well as irreversible structural and chemical changes in the cathode active material, can result in inferior electrochemical performance, particularly during high-voltage cycling (>4.3 V vs Li/Li).

Bioinspired Zwitterionic Nanowires with Simultaneous Biofouling Reduction and Release.

Marine biofouling is a complex and dynamic process that significantly increases the carbon emissions from the maritime industry by increasing drag losses. However, there are no existing non-toxic marine paints that can achieve both effective fouling reduction and efficient fouling release. Inspired by antifouling strategies in nature, herein, a superoleophobic zwitterionic nanowire coating with a nanostructured hydration layer is introduced, which exhibits simultaneous fouling reduction and release performance.

Lamination of >21% Efficient Perovskite Solar Cells with Independent Process Control of Transport Layers and Interfaces.

Transport layer and interface optimization is critical for improving the performance and stability of perovskite solar cells (PSCs) but is restricted by the conventional fabrication approach of sequential layer deposition. While the bottom transport layer is processed with minimum constraints, the narrow thermal and chemical stability window of the halide perovskite (HP) layer severely restricts the choice of top transport layer and its processing conditions. To overcome these limitations, we demonstrate lamination of HPs─where two transport layer-perovskite half-stacks are independently processed and diffusion-bonded at the HP-HP interface─as an alternative fabrication strategy that enables self-encapsulated solar cells.

Lithium Metal Anodes: Advancing our Mechanistic Understanding of Cycling Phenomena in Liquid and Solid Electrolytes.

Lithium metal anodes have the potential to be a disruptive technology for next-generation batteries with high energy densities, but their electrochemical performance is limited by a lack of fundamental understanding into the mechanistic origins that underpin their poor reversibility, morphological evolution (including dendrite growth), and interfacial instability. The goal of this perspective is to summarize the current state-of-the-art understanding of these phenomena, and highlight knowledge gaps where additional research is needed. The various stages of cycling are described sequentially, including nucleation, growth, open-circuit rest periods, and electrodissolution (stripping).

Subtractive Patterning of Nanoscale Thin Films Using Acid-Based Electrohydrodynamic-Jet Printing.

As an alternative to traditional photolithography, printing processes are widely explored for the patterning of customizable devices. However, to date, the majority of high-resolution printing processes for functional nanomaterials are additive in nature. To complement additive printing, there is a need for subtractive processes, where the printed ink results in material removal, rather than addition.

Atomic Layer Deposition of Cu Electrocatalysts on Gas Diffusion Electrodes for CO Reduction.

Electrochemical reduction of CO using Cu catalysts enables the synthesis of C products including CH and CHOH. In this study, Cu catalysts were fabricated using plasma-enhanced atomic layer deposition (PEALD), achieving conformal deposition of catalysts throughout 3-D gas diffusion electrode (GDE) substrates while maintaining tunable control of Cu nanoparticle size and areal loading. The electrochemical CO reduction at the Cu surface yielded a total Faradaic efficiency (FE) > 75% for C products.

Visible-Light-Driven Photocatalysts for Self-Cleaning Transparent Surfaces.

Highly transparent photocatalytic self-cleaning surfaces capable of harvesting near-visible (365-430 nm) photons were synthesized and characterized. This helps to address a current research gap in self-cleaning surfaces, in which photocatalytic coatings that exhibit activity at wavelengths longer than ultraviolet (UV) generally have poor optical transparency, because of broadband scattering and the attenuation of visible light. In this work, the wavelength-dependent photocatalytic activity of Pt-modified TiO (Pt-TiO) particles was characterized, which exhibited activity for wavelengths up to 430 nm.

Integrating Structural Colors with Additive Manufacturing Using Atomic Layer Deposition.

We demonstrate tunable structural color patterns that span the visible spectrum using atomic layer deposition (ALD). Asymmetric metal-dielectric-metal structures were sequentially deposited with nickel, zinc oxide, and a thin copper layer to form an optical cavity. The color response was precisely adjusted by tuning the zinc oxide (ZnO) thickness using ALD, which was consistent with model predictions.

Durable Liquid- and Solid-Repellent Elastomeric Coatings Infused with Partially Crosslinked Lubricants.

Surfaces that are resistant to both liquid fouling and solid fouling are critical for many industrial and biomedical applications. However, surfaces developed to address these challenges thus far have been generally susceptible to mechanical damage. Herein, we report the design and fabrication of robust solid- and liquid-repellent elastomeric coatings that incorporate partially crosslinked lubricating chains within a durable polymer matrix.

Geometric Optimization of Bismuth Vanadate Core-Shell Nanowire Photoanodes using Atomic Layer Deposition.

In this study, systematic geometric tuning of core-shell nanowire (NW) architectures is used to decouple the contributions from light absorption, charge separation, and charge transfer kinetics in photoelectrochemical water oxidation. Core-shell-shell NW arrays were fabricated using a combination of hydrothermal synthesis of ZnO and atomic layer deposition (ALD) of SnO and BiVO. The length and spacing of the NW scaffold, as well as the BiVO film thickness, were systematically tuned to optimize the photoelectrochemical performance.

Molecular layer deposition of Li-ion conducting "Lithicone" solid electrolytes.

We demonstrate the fabrication of Li-containing ("lithicone") thin films prepared via molecular layer deposition (MLD) using lithium tert-butoxide and ethylene glycol. X-ray photoelectron spectroscopy reveals that the stoichiometry of the lithicone is LiCO (H omitted), with C-O-Li moieties present in the film. The bonding environment of lithicone is distinct from that of lithium carbonate or MLD alucone films.

Area-Selective Atomic Layer Deposition Patterned by Electrohydrodynamic Jet Printing for Additive Manufacturing of Functional Materials and Devices.

There is an increasing interest in additive nanomanufacturing processes, which enable customizable patterning of functional materials and devices on a wide range of substrates. However, there are relatively few techniques with the ability to directly 3D print patterns of functional materials with sub-micron resolution. In this study, we demonstrate the use of additive electrohydrodynamic jet (e-jet) printing with an average line width of 312 nm, which acts as an inhibitor for area-selective atomic layer deposition (AS-ALD) of a range of metal oxides.

Inkjet-defined site-selective (IDSS) growth for controllable production of in-plane and out-of-plane MoS device arrays.

Along with the increasing interest in MoS2 as a promising electronic material, there is also an increasing demand for nanofabrication technologies that are compatible with this material and other relevant layered materials. In addition, the development of scalable nanofabrication approaches capable of directly producing MoS2 device arrays is an imperative task to speed up the design and commercialize various functional MoS2-based devices. The desired fabrication methods need to meet two critical requirements.

Enhanced Interfacial Toughness of Thermoplastic-Epoxy Interfaces Using ALD Surface Treatments.

Interfacial fracture and delamination of polymer interfaces can play a critical role in a wide range of applications, including fiber-reinforced composites, flexible electronics, and encapsulation layers for photovoltaics. However, owing to the low surface energy of many thermoplastics, adhesion to dissimilar material surfaces remains a critical challenge. In this work, we demonstrate that surface treatments using atomic layer deposition (ALD) on poly(methyl methacrylate) (PMMA) and fluorinated ethylene propylene (FEP) lead to significant increases in surface energy, without affecting the bulk mechanical response of the thermoplastic.

Biotemplated Morpho Butterfly Wings for Tunable Structurally Colored Photocatalysts.

Morpho sulkowskyi butterfly wings contain naturally occurring hierarchical nanostructures that produce structural coloration. The high aspect ratio and surface area of these wings make them attractive nanostructured templates for applications in solar energy and photocatalysis. However, biomimetic approaches to replicate their complex structural features and integrate functional materials into their three-dimensional framework are highly limited in precision and scalability.

Rational Design of Hyperbranched Nanowire Systems for Tunable Superomniphobic Surfaces Enabled by Atomic Layer Deposition.

Superomniphobic surfaces display contact angles of θ* > 150° and low contact angle hysteresis with virtually all high and low surface tension liquids. The introduction of hierarchical scales of texture can increase the contact angles and decrease the contact angle hysteresis of superomniphobic surfaces by reducing the solid-liquid contact area. Thus far, it has not been possible to fabricate superomniphobic surfaces with three or more hierarchical scales of texture where the size, spacing, and angular orientation of features within each scale of texture can be independently varied and controlled.

Dendrites and Pits: Untangling the Complex Behavior of Lithium Metal Anodes through Operando Video Microscopy.

Enabling ultra-high energy density rechargeable Li batteries would have widespread impact on society. However the critical challenges of Li metal anodes (most notably cycle life and safety) remain unsolved. This is attributed to the evolution of Li metal morphology during cycling, which leads to dendrite growth and surface pitting.

Management and Outcomes of Bleeding Events in Patients in the Emergency Department Taking Warfarin or a Non-Vitamin K Antagonist Oral Anticoagulant.

Background: Most comparisons of bleeding patients who are taking warfarin or a non-vitamin K oral anticoagulant (NOAC) have been limited to admitted patients and major bleeding events in well-controlled, clinical trial settings.

Objectives: We describe the clinical characteristics, interventions, and outcomes in patients who are taking warfarin or a NOAC who presented to the emergency department (ED) with any bleeding event.

Methods: We conducted a structured, retrospective, observational study of nonvalvular atrial fibrillation, pulmonary embolism, or deep vein thrombosis warfarin- or NOAC-treated patients presenting with any bleeding event to a large, academic ED between January 2012 and March 2015.

Macroporous p-GaP Photocathodes Prepared by Anodic Etching and Atomic Layer Deposition Doping.

P-type macroporous gallium phosphide (GaP) photoelectrodes have been prepared by anodic etching of an undoped, intrinsically n-type GaP(100) wafer and followed by drive-in doping with Zn from conformal ZnO films prepared by atomic layer deposition (ALD). Specifically, 30 nm ALD ZnO films were coated on GaP macroporous films and then annealed at T = 650 °C for various times to diffuse Zn in GaP. Under 100 mW cm(-2) white light illumination, the resulting Zn-doped macroporous GaP consistently exhibit strong cathodic photocurrent when measured in aqueous electrolyte containing methyl viologen.

Bioinspired Multifunctional Paper-Based rGO Composites for Solar-Driven Clean Water Generation.

Reusing polluted water through various decontamination techniques has appeared as one of the most practical approaches to address the global shortage of clean water. Rather than relying on single decontamination mechanism, herein we report the preparation and utilization of paper-based composites for multifunctional solar-driven clean water generation that is inspired by the multiple water purification approaches in biological systems. The reduced graphene oxide (rGO) sheets within such composites can efficiently remove organic contaminants through physical adsorption mechanism.