Effect of defects on the electronic structure of a PbI2/MoS2 van der Waals heterostructure: A first-principles study

PbI2/MoS2,as a typical van der Waals(vdW)heterostructure,has attracted intensive attention owing to its remarkable electronic and optoelectronic properties.In this work,the effect of defects on the electronic structures of a PbI2/MoS2 heterointerface has been systematically investigated.The manner in which the defects modulate the band structure of PbI2/MoS2,including the band gap,band edge,band alignment,and defect energy-level density within the band gap is discussed herein.It is shown that sulfur defects tune the band gaps,iodine defects shift the positions of the band edge and Fermi level,and lead defects realize the conversions between the straddling-gap band alignment and valence-band-aligned gap,thus enhancing the light-absorption ability of the material.     

Direct Transformation of Arenols Based on C—O Activation

In the view of substrate availability, atomic efficiency and cost, directly using arenols as coupling partners in cross‐coupling, would be one of the most attractive goals. Up to date, many efforts have been made to activate the C—O bond of phenols with different strategies, for example, through in‐situ formed intermediates, through a catalytic reductive dearomatization‐condensation‐rearomatization sequence or catalytic deoxygenation. In this review, we summarized recent advances in cross‐couplings of arenols as the electrophiles via C—O activation.     

Charge Transport through Peptides in Single‐Molecule Electrical Measurements

Charge transport across the peptide chains is one of the vital processes in the biological systems, so understanding their charge transport properties is an indispensable prerequisite to explain the complex biochemical phenomenon. Here, we review the charge transport mechanism, the influence of the special groups and the experimental conditions on the charge transport through the peptide backbone by employing the single‐molecule electrical measurements. Besides, we further review the recent progresses in charge transport properties of supramolecular interaction among the adjacent peptide chains. Finally, we discuss some experimental and theoretical contradictions existing in the charge transport through peptides and provide new inspiration for the future development of the bioelectronics at the single‐molecule scale.     

Characteristics of uranium sorption on illite in a ternary system: effect of phosphate on adsorption

Journal of Radioanalytical and Nuclear Chemistry - Na, Mg, Al and Cl in Roman glasses and pottery were analyzed by PIGE with 2.5 MeV protons and 2.0 MeV deuteron activation...     

Determination of the Absolute Configuration of Super-Carbon-Chain Compounds by a Combined Chemical,Spectroscopic, and Computational Approach: Gibbosols A and B

Marine dinoflagellates produce remarkable organic molecules, particularly those with polyoxygenated long-carbon-chain backbones, namely super-carbon-chain compounds (SCCCs), characterized by the presence of numerous stereogenic carbon centers on acyclic polyol carbon chains. Even today, it is a challenge to determine the absolute configurations of these compounds. In this work, the planar structures and absolute configurations of two highly flexible SCCCs, featuring either a C₆₉- or C₇₁-linear carbon backbone, gibbosols A and B, respectively, each containing thirty-seven stereogenic carbon centers, were unambiguously established by a combined chemical, spectroscopic, and computational approach. The discovery of gibbosols A and B with two hydrophilic acyclic polyol chains represents an unprecedented class of SCCCs. A reasonable convergent strategy for the biosynthesis of these SCCCs was proposed.     

Optimization of Active Sites via Crystal Phase,Composition, and Morphology for Efficient Low-Iridium Oxygen Evolution Catalysts

Reducing the amount of iridium in oxygen evolution electrocatalysts without compromising their catalytic performances is one of the major requirements in proton-exchange-membrane water electrolyzers. Herein, with the help of theoretical studies, we show that anatase-type TiO₂-IrO₂ solid solutions possess more active iridium catalytic sites for the oxygen evolution reaction (OER) than IrO₂, the benchmark OER catalyst. Note that the same is not observed for their rutile-type counterparts. However, owing to their thermodynamic metastability, anatase-type TiO₂-IrO₂ solid solutions are generally hard to synthesize. Our theoretical studies demonstrate that such catalytically active anatase-type solid-solution phases can be created in situ on the surfaces of readily available SrTiO₃-SrIrO₃ solid solutions during electrocatalysis in acidic solution as the solution can etch away Sr atoms. We experimentally show this with porous SrTiO₃-SrIrO₃ solid-solution nanotubes synthesized by a facile synthetic route that contain 56 % less iridium than IrO₂ yet show an order of magnitude higher apparent catalytic activity for OER in acidic solution.     

Manipulating the Click Reactivity of Dibenzoazacyclooctynes: From Azide Click Component to Caged Acylation Reagent by Silver Catalysis

Strain-promoted azide–alkyne cycloaddition using dibenzoazacyclooctyne (DBCO) is widely applied in copper-free bioorthogonal reactions. Reported here is the efficient acid-promoted rearrangement and silver-catalyzed amidation of DBCO, which alters its click reactivity robustly. In the switched click reaction, DBCO, as a caged acylation reagent, enables rapid peptide/protein modification after decaging facilitated by silver catalysts, rendering site-specific conjugation of an IgG antibody by a Fc-targeting peptide.     

Preparation of a novel bentonite intercalation composite by changing the chemical state of aluminum

A new environment-friendly bentonite intercalation composite was successfully obtained from alumina sol intercalation. This process used industrial grade pseudo boehmite as the aluminum source and provided with the advantage of zero emission of acidic wastewater. The bentonite intercalation composite was investigated by XRF, ICP, XRD, FT-IR, BET, and pyridine-FTIR. Results indicated that the basal spacing was enlarged from 14.72 to 15.60 Å; the specific surface area increased by 128%; and the total acid content increased from 65.32 to 245.76 μmol/g. The catalytic activity of this composite was tested by alkylation of aromatics with olefins. The results show that the weak Lewis acid generated by extra-framework aluminum and specific surface area play a decisive role, while weak Brønsted acid site is not the active site for this alkylation reaction.