Confronting the Issues Associated with the Practical Implementation of Zinc Blende-type SiC Anodes for Efficient and Reversible Storage of Lithium Ions

Electrochemically active zinc blende anodic materials have been envisioned to host Li+ ions at tetrahedrally configured interstitial sites, resulting in minimum volumetric expansion. Despite the silicon carbide (β-SiC) being a zinc blende system with a high theoretical specific capacity (∼1430 mAh/g) and structural robustness, it has not been studied to the extent that its other peers like Si/graphite/Sn/Al, etc. have been. By identifying and addressing the issues that currently limit commercially available β-SiC’s practically achivable storage ability, we can unlock its potential as a viable anodic material for Li+-ion battery (LIB). In this work, comprehensive structural studies on commercially procured different batches of β-SiC unveil the presence of a native suboxide passivation layer. This suboxide layer adversely affects the Li+-ions diffusion kinetics besides poor initial Coulombic efficiency and inferior reversible capacity (∼79 mAh/g @ 128th cycle). The removal of this suboxide passivation layer immediately brings a 5-fold increase in Li+-ions diffusion kinetics and an ∼53% increase in the first reversible specific capacity. The study shows the need for further assistance to increase the Li+-ions diffusion, and the surface modification by N-doped carbon is found to be competent enough to bring an ∼35-fold increase in overall lithium diffusion kinetics. This results in a noticeable increase in reversible specific capacity by more than an order of magnitude from ∼79 to ∼930 mAh/g. The modified SiC-based anodes are found to be compatible when paired with commercially available LiCoO2 in full-cells. The LiCoO2//SiC-based full cell demonstrates the capacity retention of nearly 80% post 175 cycles and is well capable of powering prototype portable electronic devices, too. The overall study suggests that commercially available silicon carbide materials are worthy of consideration as negative electrodes in LIB upon deliberate surface engineering and should be given a chance

AuFePt Ternary Homogeneous Alloy Nanoparticles with Magnetic and Plasmonic Properties

Combining Au and Fe into a single nanoparticle is an attractive way to engineer a system possessing both plasmonic and magnetic properties simultaneously. However, the formation of the AuFe alloy is challenging because of the wide miscibility gap for these elements. In this study, we synthesized AuFePt ternary alloy nanoparticles as an alternative to AuFe alloy nanoparticles, where Pt is used as a mediator that facilitates alloying between Au and Fe in order to form ternary alloy nanoparticles. The relationship among composition, structure, and function is investigated and it was found that at an optimized composition (Au₅₂Fe₃₀Pt₁₈), ternary alloy NPs exhibit both magnetic and plasmonic properties simultaneously. The plasmonic properties are investigated in detail using a theoretical Mie model, and we found that it is governed by the dielectric constant of the resulting materials

Enhanced Vertical Concentration Gradient in Rubbed P3HT:PCBM Graded Bilayer Solar Cells

Graded bilayer solar cells have proven to be at least as efficient as the bulk heterojunctions when it comes to the Poly­(3-hexylthiophene) (P3HT) - [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) donor–acceptor system. However, control of the vertical concentration gradient using simple techniques has never been reported. We demonstrate that rubbing the P3HT layer prior to PCBM deposition induces major morphological changes in the active layer. Using the newly introduced energy-dispersive X-ray spectroscopy element mapping technique, we found that rubbing P3HT induces the formation of an ideal vertical donor–acceptor concentration gradient. Furthermore, the P3HT crystallites undergo a molecular reorientation from edge-on to face-on configuration inducing a better charge transport in the vertical direction. The combination of these two major morphological changes leads to the fabrication of high-performance solar cells that exhibit, to date, the record efficiencies for spin-coated graded bilayers solar cells

High-throughput screening of multimetallic catalysts for three-way catalysis

Multimetallic nanoparticles (MNPs) have appeared as promising catalysts for important catalytic reactions such as three-way catalysis (TWC) due to their synergistic effects. Herein, a comprehensive process of preparing and evaluating MNPs and supported catalysts using high-throughput experimentation (HTE) for TWC is demonstrated. The synthesis of MNPs via a hot-injection method is performed using a homemade parallel reactor. The prepared MNPs are impregnated in parallel on alumina and examined for TWC. An in-house fixed-bed reactor equipped with a quadrupole mass spectrometer was employed for catalyst evaluation, taking advantage of the rapid screening of 20 catalysts and multiple reaction conditions. The overall HTE system can facilitate the synthesis and evaluation of 51 multimetallic catalysts for TWC in less than 2 weeks, and also appear to be a flexible and versatile system for other applications. This study outlines a comprehensive high-throughput process for synthesizing and assessing multimetallic catalysts for three-way catalysis, unveiling promising alternatives to precious metals and advancing sustainable and eco-friendly automotive emissions control.</p

Factors Affecting the Performance of Bifacial Inverted Polymer Solar Cells with a Thick Photoactive Layer

Photocurrent voltage curves and photocurrent action spectra of bifacial inverted polymer solar cells with a structure of ITO/ZnO/[6,6]-phenyl C₆₁ butyric acid methyl ester (PCBM):regioregular poly­(3-hexylthiophene) (P3HT)/poly­(3,4-ethylenedioxylenethiophene):poly­(4-styrene sulfonic acid) (PEDOT:PSS)/Au were measured. High performance was obtained when light was irradiated from each side of the devices, even for those with a 500 nm thick PCBM:P3HT layer, but an optical filter effect of the photocurrent was somewhat larger for irradiation from the Au side than that for the ITO side. These results suggested that the efficiency of photocharge separation near the ZnO/PCBM:P3HT interface was higher than that near the PCBM:P3HT/PEDOT:PSS interface, although the photocharge separation and the charge transport were smooth in the whole PCBM:P3HT layer. Further, we found that the fill factor of the photocurrent voltage curves of these devices depended on the migration distance of holes with lower mobility in the PCBM:P3HT layer

Ag/FeCo/Ag Core/Shell/Shell Magnetic Nanoparticles with Plasmonic Imaging Capability

Magnetic nanoparticles (NPs) have been used to separate various species such as bacteria, cells, and proteins. In this study, we synthesized Ag/FeCo/Ag core/shell/shell NPs designed for magnetic separation of subcellular components like intracellular vesicles. A benefit of these NPs is that their silver metal content allows plasmon scattering to be used as a tool to observe detection by the NPs easily and semipermanently. Therefore, these NPs are considered a potential alternative to existing fluorescent probes like dye molecules and colloidal quantum dots. In addition, the Ag core inside the NPs suppresses the oxidation of FeCo because of electron transfer from the Ag core to the FeCo shell, even though FeCo is typically susceptible to oxidation. The surfaces of the Ag/FeCo/Ag NPs were functionalized with ε-poly-l-lysine-based hydrophilic polymers to make them water-soluble and biocompatible. The imaging capability of the polymer-functionalized NPs induced by plasmon scattering from the Ag core was investigated. The response of the NPs to a magnetic field using liposomes as platforms and applying a magnetic field during observation by confocal laser scanning microscopy was assessed. The results of the magnetophoresis experiments of liposomes allowed us to calculate the magnetic force to which each liposome was subjected

Copper Sulfide–Zinc Sulfide Janus Nanoparticles and Their Seebeck Characteristics for Sustainable Thermoelectric Materials

A heterostructured copper sulfide–zinc sulfide nanocomposite is explored as a new class of low temperature and sustainable thermoelectric materials. The nanoparticles are created through a wet chemical synthetic technique and display a remarkable Janus structure. These nanoparticles are processed as building blocks by molecular linking with short alkyl chain ligands to enhance their electrical conductivity. The nanomaterials are pressed into a pellet and subjected to subsequent thermal annealing to remove volatiles and enhance particle contacts through sintering. The resulting nanocomposite materials were characterized to assess the thermoelectric characteristics, revealing P-type conductivity