We demonstrate low energy, forming and compliance-free operation of a resistive memory obtained by the partial oxidation of a two-dimensional layered van-der-Waals semiconductor: hafnium disulfide (HfS). Semiconductor-oxide heterostructures are achieved by low temperature (<300 °C) thermal oxidation of HfS under dry conditions, carefully controlling process parameters. The resulting HfOS/HfS heterostructures are integrated between metal contacts, forming vertical crossbar devices.
View Article and Find Full Text PDFWith no effective treatments for functional recovery after injury, spinal cord injury (SCI) remains one of the unresolved healthcare challenges. Human induced pluripotent stem cell (hiPSC) transplantation is a versatile patient-specific regenerative approach for functional recovery after SCI. Injectable electroconductive hydrogel (ECH) can further enhance the cell transplantation efficacy through a minimally invasive manner as well as recapitulate the native bioelectrical microenvironment of neural tissue.
View Article and Find Full Text PDFThe liquid-phase exfoliation process has been successfully applied to nonlayered materials to produce quasi-2D nanoplatelets. A slight variation in bonding anisotropy in the starting material can result in the formation of 2D platelet-shaped particles with a relatively low aspect ratio. This advancement offers a promising strategy to create 2D materials from previously unexplored materials.
View Article and Find Full Text PDFElectrochemical upcycling of end-of-life polyethylene terephthalate (PET) using renewable electricity offers a route to generate valuable chemicals while processing plastic wastes. However, it remains a huge challenge to design an electrocatalyst with reliable structure-property relationships for PET valorization. Herein, spinel CoO with rich oxygen vacancies for improved activity toward formic acid (FA) production from PET hydrolysate is reported.
View Article and Find Full Text PDFThe oxygen evolution reaction (OER) is a key reaction in the production of green hydrogen by water electrolysis. In alkaline media, the current state of the art catalysts used for the OER are based on non-noble metal oxides. However, despite their huge potential as OER catalysts, these materials exhibit various disadvantages including lack of stability and conductivity that hinder the wide-spread utilization of these materials in alkaline electrolyzer devices.
View Article and Find Full Text PDFCorrelative methods to characterize single entities by electrochemistry and microscopy/spectroscopy are increasingly needed to elucidate structure-function relationships of nanomaterials. However, the technical constraints often differ depending on the characterization techniques to be applied in combination. One of the cornerstones of correlative single-entity electrochemistry (SEE) is the substrate, which needs to achieve a high conductivity, low roughness, and electrochemical inertness.
View Article and Find Full Text PDFHere, we demonstrate the production of 2D nanosheets of arsenic disulfide (AsS) via liquid-phase exfoliation of the naturally occurring mineral, orpiment. The resultant nanosheets had mean lateral dimensions and thicknesses of 400 and 10 nm, and had structures indistinguishable from the bulk. The nanosheets were solution mixed with carbon nanotubes and cast into nanocomposite films for use as anodes in potassium-ion batteries.
View Article and Find Full Text PDFSemiconducting transition metal dichalcogenides are important optoelectronic materials thanks to their intense light-matter interaction and wide selection of fabrication techniques, with potential applications in light harvesting and sensing. Crucially, these applications depend on the lifetimes and recombination dynamics of photogenerated charge carriers, which have primarily been studied in monolayers obtained from labour-intensive mechanical exfoliation or costly chemical vapour deposition. On the other hand, liquid phase exfoliation presents a high throughput and cost-effective method to produce dispersions of mono- and few-layer nanosheets.
View Article and Find Full Text PDFPurpose: Epidemiological and logistical reasons are slowing the clinical validation of the molecular imaging biomarkers in the initial stages of neurocognitive disorders. We provide an updated systematic review of the recent advances (2017-2022), highlighting methodological shortcomings.
Methods: Studies reporting the diagnostic accuracy values of the molecular imaging techniques (i.
Flexible and adaptable polymer composites with high-performance reliability over wide temperature range are imperative for various applications. However, the distinct filler-matrix thermomechanical behaviors often cause severe structure damage and performance degradation upon large thermal shock. To address this issue, a general strategy is proposed to construct leakage-free, self-adaptive, stable percolation networks in polymer composites over wide temperature (77-473 K) with biphasic GaIn alloy.
View Article and Find Full Text PDFCobalt oxide (CoO)-based nanostructures have the potential as low-cost materials for lithium-ion (Li-ion) and sodium-ion (Na-ion) battery anodes with a theoretical capacity of 890 mAh/g. Here, we demonstrate a novel method for the production of CoO nanoplatelets. This involves the growth of flower-like cobalt oxyhydroxide (CoOOH) nanostructures at a polarized liquid|liquid interface, followed by conversion to flower-like CoO via calcination.
View Article and Find Full Text PDFACS Appl Mater Interfaces
August 2023
Transparent conductors (TCs) represent key components in many applications from optoelectronic devices to electromagnetic shielding. While commercial applications typically use thin films of indium tin oxide, this material is brittle and increasingly scarce, meaning higher performing and cheaper alternatives are sought after. Solution-processible metals would be ideal owing to their high conductivities and printability.
View Article and Find Full Text PDFThe research proposes to investigate the psychological reasons that may explain women's addiction to smoking during pregnancy and the perception of combustible cigarettes, electronic cigarettes and heated tobacco cigarettes. The sample included 30 participants who smoke or people who previously smoked who chose to quit or continue smoking during pregnancy. The data was gathered via a semi-structured interview and developed from three research questions: feelings, opinions and perceptions of pregnant women toward e-cigarettes, heated tobacco cigarettes, and combustible cigarettes.
View Article and Find Full Text PDFNickel-iron layered double hydroxides are known to be one of the most highly active catalysts for the oxygen evolution reaction in alkaline conditions. The high electrocatalytic activity of the material however cannot be sustained within the active voltage window on timescales consistent with commercial requirements. The goal of this work is to identify and prove the source of inherent catalyst instability by tracking changes in the material during OER activity.
View Article and Find Full Text PDFPseudocapacitive charge storage in TiCT MXenes in acid electrolytes is typically described as involving proton intercalation/deintercalation accompanied by redox switching of the Ti centres and protonation/deprotonation of oxygen functional groups. Here we conduct nanoscale electrochemical measurements in a unique experimental configuration, restricting the electrochemical contact area to a small subregion (0.3 µm) of a monolayer TiCT flake.
View Article and Find Full Text PDFOne of the weaknesses of silicon-based batteries is the rapid deterioration of the charge-storage capacity with increasing cycle numbers. Pure silicon anodes tend to suffer from poor cycling ability due to the pulverization of the crystal structure after repeated charge and discharge cycles. In this work, we present the synthesis of a hollow nanostructured SiO material for lithium-ion anode applications to counter this drawback.
View Article and Find Full Text PDFVery recently, it has been reported that mixed transition metal oxide (TMO)/MXene catalysts show improved performance over TMO only catalysts for the oxygen evolution reaction (OER). However, the reasoning behind this observation is unknown. In this work mixed Co(OH)/TiCT were prepared and characterized for the OER using ex situ and operando spectroscopy techniques in order to initiate the understanding of why mixed TMO/MXene materials show better performances compared to TMO only catalysts.
View Article and Find Full Text PDF2D material hydrogels have recently sparked tremendous interest owing to their potential in diverse applications. However, research on the emerging 2D MXene hydrogels is still in its infancy. Herein, we show a universal 4D printing technology for manufacturing MXene hydrogels with customizable geometries, which suits a family of MXenes such as NbCT, TiCT, and MoTiCT.
View Article and Find Full Text PDFRecently, there is a growing interest in road safety assessments based on the examination of the characteristics of the road aimed at identifying the presence of risk factors. This approach, named road assessment program or network wide road safety assessment, is required by the EU Directive 2019/1936 on road infrastructure safety management. Reliable procedures for assessing the inherent safety of all the elements of the road network are required to conduct roadway safety assessments.
View Article and Find Full Text PDFIron oxide (Fe O ) is an abundant and potentially low-cost material for fabricating lithium-ion battery anodes. Here, the growth of α-Fe O nano-flowers at an electrified liquid-liquid interface is demonstrated. Sonication is used to convert these flowers into quasi-2D platelets with lateral sizes in the range of hundreds of nanometers and thicknesses in the range of tens of nanometers.
View Article and Find Full Text PDFDeveloping a simple, cheap, and scalable synthetic method for the fabrication of functional nanomaterials is crucial. Carbon-based nanowire nanocomposites could play a key role in integrating group IV semiconducting nanomaterials as anodes into Li-ion batteries. Here, we report a very simple, one-pot solvothermal-like growth of carbonaceous germanium (C-Ge) nanowires in a supercritical solvent.
View Article and Find Full Text PDFLithium-sulfur battery is one of promising candidates for next-generation energy storage device due to the sulfur cathode material with low cost and nontoxicity, and super high theoretical energy density (nearly 2600Wh kg ) and specific energy (2567Wh kg ). Sulphur, however, poses a few interesting challenges before it can gain widespread utilisation. The biggest issue is known as the polysulphide shuttling effect which contributes to rapid capacity loss after cycling.
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