Hustedjantzen8940

Bilayer spin crossover (SCO)@polymer nanocomposites show robust and controllable actuation cycles upon an electrical stimulus. The anisotropic shape of the embedded particles as well as the mechanical coupling between the SCO particles and the matrix can substantially intensify the work output of the actuators.In this short review, we provide an overview of our efforts in developing a family of anodically coloring electrochromic (EC) molecules that are fully transparent and colorless in the charge neutral state, and that can rapidly switch to a vibrantly colored state upon oxidation. We employ molecules with reduced conjugation lengths to center the neutral state absorption of the electrochrome in the ultraviolet, as desired for highly transparent and colorless materials. Oxidation creates radical cations that absorb light in the visible and near infrared regions of the electromagnetic spectrum, thus providing a host of accessible colors. Combining a density functional theory (DFT) computational approach fed back to the synthetic effort, target molecules are proposed, synthesized and studied, directing us to develop a complete color palette based on these high contrast ACE molecules. Utilizing pendant phosphonic acid binding substituents in concert with high surface area mesoporous indium tin oxide (ITO) electrodes, the electrochromes can be distributed throughout the oxide film, bringing high extent of light absorption and color density.The linear Pd8 complex supported by tetraphosphines reacted with HBF4 to give an unprecedented linear tetrapalladium complex with a terminal hydride, which promoted electrocatalytic hydrogen formation from HBF4 in acetonitrile. The 1D coordination polymer of Pd8 chain confined within Nafion film was applied to the electrocatalytic H2 formation.A composite catalyst with a novel construction of bimetallic phosphide FeNiP nanoparticles embedded in an N,P double-doped carbon matrix was prepared. It was demonstrated to be a trifunctional catalyst that can efficiently catalyze the oxygen reduction reaction (ORR), oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). It was found that the introduction of oleylamine during the preparation can adjust the catalytic sites and finally lead to ideal catalytic performances. The obtained catalyst exhibited efficient ORR catalytic performance that surpassed the commercial Pt/C catalyst, with the OER performance comparable to that of RuO2 as well as excellent HER performance. The ORR half-wave potential is 0.879 V (vs. RHE) in 0.1 M KOH solution, while the OER overpotential at a current density of 10 mA cm-2 is only 280 mV in 1 M KOH solution. The potential gap between the ORR and OER was only 0.700 V in 0.1 M KOH solution. This trifunctional catalyst was further evaluated in energy devices including zinc-air batteries and water electrolysis. The liquid zinc-air battery assembly achieved a power density of 169 mW cm-2 and stably undergoes charge-discharge cycles for 210 hours. The solid-state zinc-air battery achieved a power density of 70 mW cm-2 and stably undergoes charge-discharge cycles for 40 hours. These performances surpassed the batteries assembled with a Pt/C-RuO2 mixed catalyst. This work established a foundation of composite catalysts coupled with bimetallic phosphide and hybrid carbon substrates, which will promote the development of high-performance multifunctional catalysts and their application in energy devices.Self-driven photodetectors are essential for many applications where it is unpractical to provide or replace power sources. Here, we report a new device architecture for self-driven photodetectors with tunable asymmetric Schottky junctions based on a nanomesh electrode. The vertical-channel nanomesh scaffold is composed of a hexagonally ordered nanoelectrode array fabricated via the nanosphere lithography technique. The top and bottom nanoelectrodes are separated by only 30 nm and the areal ratio of the two nanoelectrodes can be fine-tuned, which effectively modifies the geometric asymmetricity of the Schottky junctions in the photodetector devices. The self-driven photodetectors are fabricated by depositing the (FAPbI3)0.97(MAPbBr3)0.03 (MA = methylammonium, FA = formamidinium) perovskite films onto the nanomesh electrodes. Under the self-driven mode, the optimized device demonstrates a high detectivity of 1.05 × 1011 Jones and a large on/off ratio of 2.1 × 103. This nanomesh electrode is very versatile and can be employed to investigate the optoelectronic properties of various semiconducting materials.RNA is a central player in biological processes, but there remain major gaps in our understanding of transcriptomic processes and the underlying biochemical mechanisms regulating RNA in cells. A powerful strategy to facilitate molecular analysis of cellular RNA is the metabolic incorporation of chemical probes. In this review, we discuss current approaches for RNA metabolic labeling with modified ribonucleosides and their integration with Next-Generation Sequencing, mass spectrometry-based proteomics, and fluorescence microscopy in order to interrogate RNA behavior in its native context.Transition metal nitrides are key intermediates in the catalytic reduction of dinitrogen to ammonia. To date, transition metal nitride complexes with the triphenolamine (TPA) ligand have not been reported and the system with the ligand has been much less studied for ammonia formation compared with other systems. Herein, we report a series of molybdenum complexes supported by a sterically demanding TPA ligand, including a nitrido complex NMo(TPA). We achieved the stoichiometric conversion of the nitride moiety into ammonia under ambient conditions by adding proton and electron sources to NMo(TPA). However, the catalytic turnover for N2 reduction to ammonia was not observed in the triphenolamine ligand system unlike the Schrock system-triamidoamine ligand. Density functional theory calculation revealed that the molybdenum center favors binding NH3 over N2 by 16.9 kcal mol-1 and the structural lability of the trigonal bipyramidal (TBP) molybdenum complex seems to prevent catalytic turnover. Our systematic study showed that the electronegativity and bond length of ancillary ligands determine the preference between N2 and NH3, suggesting a systematic design strategy for improvement.Decades of research on solute-induced phase transformation of metal hydride systems have shown the possibility to enhance hydrogen storage properties through novel material design such as nanoconfinement engineering. Nevertheless, the fundamentals of mechanical stress effect on confined Pd nanoparticles remain yet to be elucidated due to the difficulty in linking with hydrogen sorption thermodynamics. Here, a thermodynamic tuning of Pd nanocubes associated with hydrogen sorption as a result of encapsulation by reduced graphene oxide (rGO) layers is demonstrated. Pd nanocubes are constrained by rGO to such a degree that the chemical potential and the pressure hysteresis of the system during hydrogen sorption drastically change while showing a size dependence. A thorough thermodynamic analysis elucidates the role of constraints on hydrogen uptake and release; despite the nanoscale regime, the thermodynamic parameters (enthalpy and entropy) during phase transition considerably increase, a phenomenon not seen before in unconstrained Pd nanoparticle systems.Tantalum-based layered perovskites have always been an interesting topic in photocatalysis, but limited information has been reported in terms of their layer factor. In this work, we have synthesized Dion-Jacobson layered perovskites (A'[An-1TanO3n+1]) of LaTaO4, KLaTa2O7, and KCa2Ta3O10 with n = 1, 2, and 3, respectively. With the modification of 1 wt% Pt co-catalysts, the photocatalytic analysis showed that the performance order of these layered perovskites with different layers is KLaTa2O7 (n = 2) > KCa2Ta3O10 (n = 3) ≫ LaTaO4 (n = 1) with both methanol and NaI as the sacrificial agents. This suggested the importance of interlayer K+ for high photocatalytic performance. We further analyzed the layered perovskites in detail by BET, photoelectrochemical analysis, Mott-Schottky, and VB-XPS test. see more The combined results indicated that the positions of the conduction band are the dominant factors for the photocatalytic performance of tantalum-based Dion-Jacobson layered perovskites with n = 2 and 3. This work sheds new light on the field of layered perovskites as efficient photocatalysts.Utilizing the programmability of the fractal DNA frameworks, multi-color probes were constructed by arranging fluorescent molecules and nucleic acid aptamers on the structure. Multiplexed cell imaging and classification was realized through pattern recognition.The interplay of bond strength and covalency are examined in AnO2Cl2(OPcy3)2 (An = Pu, U) complexes. The synthesis of trans-PuO2Cl2(OPcy3)2, 1-Pu, has been carried out and confirmed by single crystal X-ray diffraction along with UV-vis-NIR, and 31P NMR spectroscopies. Theoretical analysis finds that despite a higher calculated covalency for the Pu-Cl interaction, the Pu-OPcy3 interaction is stronger due to the accumulation of electron density in the interatomic region. The coordination of equatorial ligands slightly decreases the strength of the PuOyl interactions relative to the free gas phase (PuO2)2+ ion.The charge-transport dynamics at the dye-TiO2 interface plays a vital role for the resulting power conversion efficiency (PCE) of dye sensitized solar cells (DSSCs). In this work, we have investigated the charge-exchange dynamics for a series of organic dyes, of different complexity, and a small model of the semiconductor substrate TiO2. The dyes studied involve L1, D35 and LEG4, all well-known organic dyes commonly used in DSSCs. The computational studies have been based on ab initio molecular dynamics (aiMD) simulations, from which structural snapshots have been collected. Estimates of the charge-transfer rate constants of the central exchange processes in the systems have been computed. All dyes show similar properties, and differences are mainly of quantitative character. The processes studied were the electron injection from the photoexcited dye, the hole transfer from TiO2 to the dye and the recombination loss from TiO2 to the dye. It is notable that the electronic coupling/transfer rates differ signifi thus contribute to a higher PCE of DSSCs. It is also notable that no simple correlation can be identified between high/low transfer rate constants and specific structural arrangements in terms of atom-atom distances, angles or dihedral arrangements of dye sub-units.Explosives should be isolated from the air to reduce the surface erosion by water vapor in the storage and transport processes. The CL-20/TNT cocrystal was chosen as the research object on account of its structural arrangement and weak intermolecular interactions. A relatively extreme assumption that water molecules and the CL-20/TNT cocrystal existed as a solution system on the interface was proposed to investigate the influence mechanism. CL-20/TNT-water interfacial models were constructed, based on four important stable surfaces predicted using crystal morphology theory. The roughness and the electrostatic potential of each surface were analyzed to judge the strength of interactions between the water layer and the cocrystal surface. The effects of the water layer on the crystal surfaces were quantified in terms of binding energy and the radial distribution function using molecular dynamics simulations. Based on the analysis above, the (0 0 2) face was identified as the least affected by water erosion and its growth should be promoted.