In Situ Analytical Techniques for the Investigation of Material Stability and Interface Dynamics in Electrocatalytic and Photoelectrochemical Applications.

Electrocatalysis and photoelectrochemistry are critical to technologies like fuel cells, electrolysis, and solar fuels. Material stability and interfacial phenomena are central to the performance and long-term viability of these technologies. Researchers need tools to uncover the fundamental processes occurring at the electrode/electrolyte interface.

Solvation of NiOfor hole transport layer deposition in perovskite solar cells.

A series of nickel oxide (NiO) inks, in the perovskite antisolvent chlorobenzene (CB) containing 15% ethanol, were prepared for the fabrication of p-i-n perovskite solar cells by blade coating. The inks included triethylamine (EtN) and alkyl xanthate salts as ligands to disperse NiOparticle aggregates and stabilize suspension. A total of four inks were evaluated: 0X (EtN with no alkyl xanthate), 4X (EtN + potassium-butyl xanthate), 12X (EtN + potassium-dodecyl xanthate), and 18X (EtN + potassium-octadecyl xanthate).

Visualization of Solid-State Synthesis for Chalcogenide Na Superionic Conductors by in-situ Neutron Diffraction.

Chalcogenide superionic sodium (Na) conductors have great potential as solid electrolytes (SEs) in all-solid-state Na batteries with advantages of high energy density, safety, and cost effectiveness. The crystal structures and ionically conductive properties of solid Na-ion conductors are strongly influenced by synthetic approaches and processing parameters. Thus, understanding the synthesis process is essential to control the structures and phases and to obtain Na-ion conductors with desirable properties.

Shielding Effect of Nanomicelles: Stable and Catalytically Active Oxidizable Pd(0) Nanoparticle Catalyst Compatible for Cross-Couplings of Water-Sensitive Acid Chlorides in Water.

Under the shielding effect of nanomicelles, a sustainable micellar technology for the design and convenient synthesis of ligand-free oxidizable ultrasmall Pd(0) nanoparticles (NPs) and their subsequent catalytic exploration for couplings of water-sensitive acid chlorides in water is reported. A proline-derived amphiphile, PS-750-M, plays a crucial role in stabilizing these NPs, preventing their aggregation and oxidation state changes. These NPs were characterized using C nuclear magnetic resonance (NMR), infrared (IR), and surface-enhanced Raman scattering (SERS) spectroscopy to evaluate the carbonyl interactions of PS-750-M with Pd.

Magnetism versus band-gap relationship in diluted magnetic semiconductors: megatom impurity behavior of the magnetic dopant complexes.

An analysis ofnumerical results obtained for the total energy of diluted magnetic semiconductors (DMSs) doped with dopant formations of various structural and spin conformations consisting of 2-4 3D transition metal (TM atoms) has revealed that a dopant formation acts as large impurity atom i.e., as a, in a reverse analogy to the process of the adsorption of-atoms onto metallic surfaces.

Metal-Micelle Cooperativity: Phosphine Ligand-Free Ultrasmall Palladium(II) Nanoparticles for Oxidative Mizoroki-Heck-type Couplings in Water at Room Temperature.

The amphiphile PS-750-M generates stable, phosphine ligand-free, and catalytically active ultrasmall Pd(II) nanoparticles (NPs) from Pd(OAc), preventing their precipitation, polymerization, and oxidation state changes. PS-750-M directly interacts with Pd(II) NP surfaces, as confirmed by high-resolution mass spectrometry and IR spectroscopy, resulting in their high stability. The Pd cations in NPs are most likely held together by hydroxides and acetate ions.

Chemical Vapor Transport Route toward Black Phosphorus Nanobelts and Nanoribbons.

Chemical vapor transport (CVT) method is widely used for bulk black phosphorus (BP) fabrication. In this work, we demonstrate that CVT provides a route for the fabrication of BP nanoribbons and nanobelts. This method consists of a two-step procedure, including initial BP column growth using the CVT technique, followed by ultrasonic treatment and centrifugation.

Surface Modification of Nanocrystalline LiMnO Using Graphene Oxide Flakes.

In this work, a facile, wet chemical synthesis was utilized to achieve a series of lithium manganese oxide (LiMnO, (LMO) with 1-5%wt. graphene oxide (GO) composites. The average crystallite sizes estimated by the Rietveld method of LMO/GO nanocomposites were in the range of 18-27 nm.

Codoping induced enhanced ferromagnetism in diluted magnetic semiconductors.

The experimentally observed-magnetism and its subsequent attribution to the presence of structural and topological defects has opened the way for engineering the magnetic properties of diluted magnetic semiconductors (DMSs) and transition metal oxides (TMOs). Doping and codoping constitute the most commonly used processes (either experimentally or theoretically) for developing and studying this type of defect-induced magnetism. The focus of the present review is to highlight the basic features of the defect magnetism which have been observed over diverse systems, while emphasizing the local, holistic and synergistic response of the host materials to their doping and investigating their role in the development of the magnetic coupling (MC) that is developed among the magnetic dopants.

High temperature stability, metallic character and bonding of the SiBN planar structure.

The family of monolayered SiBN structures constitute a new class of 2D materials exhibiting metallic character with remarkable stability. Topologically, these structures are very similar to graphene, forming a slightly distorted honeycomb lattice generated by a union of two basic motifs with AA and AB stacking. In the present work we study in detail the structural and electronic properties of these structures in order to understand the factors which are responsible for their structural differences as well as those which are responsible for their metallic behavior and bonding.

Estimation of-exchange constants revisited.

We present a new computational method for estimating the-exchange constant,Jeffsp-d, applicable to transition metal doped diluted magnetic semiconductors, transition metal oxides, and 2D- and 3D- dichalcogenides. The proposed method is based on results describing the variation of the magnetic features of a doped system with the variation of its magnetization density (). The results forJeffsp-d(M)obtained with the proposed method are compared with the corresponding results,Jeffsp-d(ΔEVBM), obtained from estimations of the spin electron orbital splitting, Δ, at the valence band maximum (VBM).

Insight the process of hydrazine gas adsorption on layered WS: a first principle study.

The process of hydrazine gas adsorption on layered WS has been systematically studied from first principle calculations. Our results demonstrate that this adsorption process is exothermic, and hydrazine molecules are physically adsorbed. The layer-dependent adsorption energy and interlayer separation induced by van der Waals interaction exerted by hydrazine molecules lead to the difficulty in desorbing hydrazine molecules from layered WS as the number of layers increases.

Stable and Flexible Sulfide Composite Electrolyte for High-Performance Solid-State Lithium Batteries.

Sulfide-based lithium (Li)-ion conductors represent one of the most popular solid electrolytes (SEs) for solid-state Li metal batteries (SSLMBs) with high safety. However, the commercial application of sulfide SEs is significantly limited by their chemical instability in air and electrochemical instability with electrode materials (metallic Li anode and oxide cathodes). To address these difficulties, here, we design and successfully demonstrate a novel sulfide-incorporated composite electrolyte (SCE) through the combination of inorganic sulfide Li argyrodite (LiPS) with poly(vinylidenefluoride--hexafluoropropylene) (PVDF-HFP) polymer.

ZnO ALD-Coated Microsphere-Based Sensors for Temperature Measurements.

In this paper, the application of a microsphere-based fiber-optic sensor with a 200 nm zinc oxide (ZnO) coating, deposited by the Atomic Layer Deposition (ALD) method, for temperature measurements between 100 and 300 °C, is presented. The main advantage of integrating a fiber-optic microsphere with a sensing device is the possibility of monitoring the integrity of the sensor head in real-time, which allows for higher accuracy during measurements. The study has demonstrated that ZnO ALD-coated microsphere-based sensors can be successfully used for temperature measurements.

Iodine activation: a general method for catalytic enhancement of thiolate monolayer-protected metal clusters.

To enhance catalytic activity, the present study details a general approach for partial thiolate ligand removal from monolayer-protected clusters (MPCs) by straightforward in situ addition of iodine. Two model reactions are examined to illustrate the effects on the catalytic activity of glutathione (SG)-capped Au MPCs serving as a catalyst for the NaBH4 reduction of 4-nitrophenol to 4-aminophenol and SG-capped Pd MPCs serving as a catalyst for the hydrogenation/isomerization of allyl alcohol. Iodine addition promoted partial thiolate ligand removal from both MPCs and improved the catalytic properties, presumably due to greater surface exposure of the metal cores as a result of ligand dissociation.

Pulsed Electrochemical Carbon Monoxide Reduction on Oxide-Derived Copper Catalyst.

Efficient electroreduction of carbon dioxide has been a widely pursued goal as a sustainable method to produce value-added chemicals while mitigating greenhouse gas emissions. Processes have been demonstrated for the electroreduction of CO to CO at nearly 100 % faradaic efficiency, and as a consequence, there has been growing interest in the further electroreduction of carbon monoxide. Oxide-derived copper catalysts have promising performance for the reduction of CO to hydrocarbons but have still been unable to achieve high selectivity to individual products.

Gas adsorption and light interaction mechanism in phosphorene-based field-effect transistors.

Phosphorene-based field effect transistor (FET) structures were fabricated to study the gas- and photo-detection properties of phosphorene. The interplay between device performance and environmental conditions was probed and analyzed using in situ transport measurements. The device structures were exposed to different chemical and light environments to understand how they perform under different external stimuli.

Revealing Long-Range Substituent Effects in the Laser-Induced Fluorescence and Dispersed Fluorescence Spectra of Jet-Cooled CHFCHO ( = 1, 2, 3) Radicals.

The B̃-X̃ laser-induced fluorescence (LIF) and dispersed fluorescence (DF) spectra of the atmospherically important β-monofluoro ethoxy (MFEO), β,β-difluoro ethoxy (DFEO), and β,β,β-trifluoro ethoxy (TFEO) radicals were recorded with vibronic resolution under jet-cooled conditions. To simulate the spectra, Franck-Condon factors were obtained from quantum chemical computations carried out at the CAM-B3LYP/6-311++G(d,p) level of theory. The simulations reproduce well both the LIF and DF spectra.

An "In-Situ Binding" Approach to Produce Torrefied Biomass Briquettes.

Biomass-derived coal or "biocoal" produced using a torrefaction process presents a carbon-neutral option of coal for power generation. While torrefaction delivers a carbon content and hydrophobicity comparable to coal, it lowers its density and creates material handling, storage, and transportation challenges. Densification into briquettes would help mitigate these challenges.

Laser-Induced Fluorescence and Dispersed Fluorescence Spectroscopy of Jet-Cooled Isopentoxy Radicals.

The B̃-X̃ laser-induced fluorescence (LIF) and dispersed fluorescence (DF) spectra of jet-cooled isopentoxy radicals have been obtained. The LIF spectrum of isopentoxy lacks strong transitions to the CO-stretch levels that are typical for alkoxy radicals. Instead, it contains two low-frequency vibrational progressions due to large-amplitude motions of the GG' and GG conformers involving torsion of the CCCH dihedral angle.

Photocatalytic hydrogen evolution on Si photocathodes modified with bis(thiosemicarbazonato)nickel(ii)/Nafion.

The molecular catalyst diacetyl-bis(N-4-methyl-3-thiosemi-carbazonato)nickel(ii) (NiATSM) was integrated with Si for light-driven hydrogen evolution from water. Compared to an equivalent loading of Ni metal, the NiATSM/p-Si electrode performed better. Durability of the surface-bound catalyst under operation in acid was achieved without covalent attachment by using Nafion binding.

Synthesis and Properties of NaSICON-type LATP and LAGP Solid Electrolytes.

Inorganic solid electrolytes play a critical role in solid-state lithium batteries achieving high safety levels and high energy densities. The synthetic approaches to solid electrolytes are important for both fundamental research and practical applications. Li Al Ti (PO ) (LATP) and Li Al Ge (PO ) (LAGP) are two representative solid electrolytes with a sodium superionic conductor (NaSICON) structure.

A new nanowire-based lithium hexaoxotungstate anode for lithium-ion batteries.

This study reports one dimensional lithium hexaoxotungstate (LiWO), with a diameter in the range of 200-500 nm, as a novel anode material for lithium-ion batteries. The electrochemical performance of lithium hexaoxotungstate was investigated and a discharge capacity of 705 mA h g was achieved after 50 cycles, along with an excellent rate capability. The 1D morphology of the material is believed to provide excellent transport properties, resulting in a high rate capability.

Organopolymer with dual chromophores and fast charge-transfer properties for sustainable photocatalysis.

Photocatalytic polymers offer an alternative to prevailing organometallics and nanomaterials, and they may benefit from polymer-mediated catalytic and material enhancements. MPC-1, a polymer photoredox catalyst reported herein, exhibits enhanced catalytic activity arising from charge transfer states (CTSs) between its two chromophores. Oligomeric and polymeric MPC-1 preparations both promote efficient hydrodehalogenation of α-halocarbonyl compounds while exhibiting different solubility properties.

Room-Temperature Cavity Ring-Down Spectroscopy of Methylallyl Peroxy Radicals.

We report room-temperature cavity ring-down (CRD) spectra of the à ← X̃ electronic transition of 1-, 2-, and 3-methylallyl peroxy (MAOO) radicals produced by 193 nm photolysis of methyl-substituted allyl chlorides in the presence of O. Vibronic structure of experimentally observed spectra was simulated using calculated relative populations of MAOO conformers, their electronic transition frequencies and oscillator strengths, as well as their vibrational frequencies and Franck-Condon factors of the à ← X̃ electronic transition. The reaction intermediate for the production of 1- and 3-MAOO radicals, CHCHCHCH, is a resonance-stabilized free radical.