Computational evaluation of CO conversion into formic acid via a novel adsorption mechanism on metal-free BC.

The electrochemical reduction of CO (CO2RR) to formic acid (HCOOH) is a promising approach to harness renewable energy for the production of value-added chemicals and contribute to carbon cycling. The search for cost-effective and efficient metal-free electrocatalysts is critical for realizing industrial applications. However, limited literature is available on this topic, primarily because the significant challenge of efficiently activating inert CO remains unresolved.

Graphynes and Graphdiynes for Energy Storage and Catalytic Utilization: Theoretical Insights into Recent Advances.

Carbon allotropes have contributed to all aspects of people's lives throughout human history. As emerging carbon-based low-dimensional materials, graphyne family members (GYF), represented by graphdiyne, have a wide range potential applications due to their superior physical and chemical properties. In particular, graphdiyne (GDY), as the leader of the graphyne family, has been practically applied to various research fields since it was first successfully synthesized.

Encapsulated ruthenium nanoparticles activated few-layer carbon frameworks as high robust oxygen evolution electrocatalysts in acidic media.

Noble metals have been extensively employed as high active catalysts for oxygen evolution reaction (OER), are usually subjected to serious surface transformation and poor structural stability, especially in acid media, which need imperatively remedied. Herein, the interfacial engineering of Ru via few-layer carbon (Ru@FLC) was carried out, in which FLC can significantly suppress the corrosion of Ru in acid media, ensuring the efficient interfacial charge transport between Ru and FLC. As a result, a low overpotentials@10 mA cm of 258 mV and small Tafel slopes of 53.

CN: A novel 2D carbon nitride with sp-N as support for efficient hydrogen production.

Two-dimensional (2D) carbon nitrides (CN) have great potential in advanced fields such as energy harvest and storage. We report a novel 2D CN, CN, comprising sp-N and sp-C atoms. Density functional theory calculations indicate that electronically, thermally, and dynamically stable CN is metallic even when cut into very narrow nanoribbons.

A simple general descriptor for rational design of graphyne-based bifunctional electrocatalysts toward hydrogen evolution and oxygen reduction reactions.

The high cost and relative scarcity of platinum (Pt) restrict large-scale commercialization of fuel cells, which has spurred researchers to develop low-cost alternatives integrating with high hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) catalytic activity. Herein, we performed density functional theory (DFT) calculations to explore the electrocatalytic activity of graphyne nanotubes (GyNTs). Several GyNTs were found to be potential metal-free electrocatalysts, with both HER and ORR activity superior to Pt.

Porous CoSe@N-doped carbon nanowires: an ultra-high stable and large-current-density oxygen evolution electrocatalyst.

Nitrogen doped carbon functionalized CoSe nanowires (CoSe@N-C NWs), which act as potential oxygen evolution reaction (OER) catalysts with a large current density and high stability have been reported. Owing to the collaborative optimization of electrical conductivity, free adsorption energy and binding strength of OER intermediates, the prepared CoSe@N-C NWs exhibit an enhanced 6.61-fold catalytic activity compared to the pristine CoSe NW electrode in 1.

Ce-Mn coordination polymer derived hierarchical/porous structured CeO-MnO for enhanced catalytic properties.

Catalytic performance is largely dependent on how the structures/compositions of materials are designed. Herein, CeO2-MnOx binary oxide catalysts with a hierarchical/porous structure are prepared by a facile and efficient method, which involves the preparation of the hierarchical Ce-Mn coordination polymer (CPs) precursor, followed by a thermal treatment step. The obtained CeO2-MnOx catalysts not only well inherit the hierarchical structure of Ce-Mn CPs, but also possess porous and hollow features due to the removal of organic ligands and heterogeneous contraction during the calcination process.

γ-Graphyne nanotubes as defect-free catalysts of the oxygen reduction reaction: a DFT investigation.

Graphyne materials are potential candidates to fabricate low-cost but efficient metal-free oxygen reduction reaction (ORR) electrocatalysts. However, due to the coexistence of sp and sp2 carbon atoms in graphyne, some factors playing important roles in determining the ORR activity have received little attention. In the present paper, we carried out thorough density functional theory (DFT) calculations to study the curvature effect on the ORR activity of γ-graphyne.

Graphyne-anchored single Fe atoms as efficient CO oxidation catalysts as predicted by DFT calculations.

By performing first-principles calculations, CO oxidation catalyzed by Fe-embedded defective α-graphyne was systematically investigated. It was found that Fe atoms were strongly anchored at the sp-C vacancy site of α-graphyne with a large binding energy of -5.28 eV and effectively adsorbed and activated O2 molecules.

Tandem Catalysis of Ammonia Borane Dehydrogenation and Phenylacetylene Hydrogenation Catalyzed by CeO Nanotube/Pd@MIL-53(Al).

Heterogeneously catalyzed, selective hydrogenation in the liquid phase is widely used in industry for the synthesis of chemicals. However, it can be a challenge to prevent active nanoparticles (e.g.

Engineering of the d-Band Center of Perovskite Cobaltite for Enhanced Electrocatalytic Oxygen Evolution.

Great efforts have been made to understand and upgrade the kinetically sluggish oxygen evolution reaction (OER). In this study, a series of V-doped LaCoO (V-LCO) OER electrocatalysts with optimized d-band centers are fabricated. When utilized as an electrode for the OER, as-formed LaCo V O (V-LCO-II) requires an overpotential of only 306 mV to drive a geometrical catalytic current density of 10 mA cm .

Novel Disassembly Mechanisms of Sigmoid Aβ Protofibrils by Introduced Neutral and Charged Drug Molecules.

Alzheimer's disease (AD) is characterized by fibrillar deposits of amyloid-β (Aβ) peptides and neurofibrillary tangles of Tau proteins. Aβ peptides are composed of 37-49 residues, among which the Aβ isoform is particularly toxic and aggregation-prone and is enriched in the plaques of AD brains and thus considered central to the development of AD. Therefore, disaggregation and disruption provide potential therapeutic approaches to reduce, inhibit, and even reverse Aβ aggregation.

Synergy of sp-N and sp-N codoping endows graphdiyne with comparable oxygen reduction reaction performance to Pt.

Nitrogen doped graphdiyne (NGDY) has been reported to have comparable oxygen reduction reaction (ORR) performance to Pt-based catalysts. However, the source of this enhanced ORR performance is not clearly understood. Herein, density functional theory calculations were performed to study the detailed ORR process on NGDY.

An Original Monomer Sampling from a Ready-Made Aβ NMR Fibril Suggests a Turn-β-Strand Synergetic Seeding Mechanism.

Aggregation of amyloid beta (Aβ) is a central step of Alzheimer's disease. Aβ42 monomers are building blocks in the formation of both "on pathway" intermediate structures and "off pathway" oligomers. How to sample an Aβ monomer becomes a problem however due to the instinct of Aβ high flexibility and diversity as well as aggregation propensity.

Tautomerization Effect of Histidines on Oligomer Aggregation of β-Amyloid(1-40/42) during the Early Stage: Tautomerism Hypothesis for Misfolding Protein Aggregation.

As the intrinsic origin of the hypothesis for β-amyloid (Aβ) from Alzheimer's disease, histidine behaviors were found to play a crucial role in Aβ aggregation. To investigate the histidine behaviors during the early stage of aggregation, Aβ40/42 pentamers with different histidine isomer states were simulated at the atomic level. Results show that five Aβ40 (δδδ) and Aβ42 (εδδ) monomers can rapidly decrease the aggregation threshold, promote stable pentamer formation, and increase pentamer contents by 51.

Chiral γ-graphyne nanotubes with almost equivalent bandgaps.

Analogous to conventional carbon nanotubes, single-walled, chiral, γ-graphyne nanotubes (C-γGyNTs) are modeled based on the synthesized 2D γ-graphyne motif, and their electronic properties are investigated via density-functional tight-binding calculations for the first time. The resulting γGyNTs are predicted to be excellent semiconductors with moderate bandgaps ranging from 1.291 eV to 1.

A highly specific and ultrasensitive p-aminophenylether-based fluorescent probe for imaging native HOCl in live cells and zebrafish.

It is very important to detect native hypochlorous acid (HOCl) in the complex biosystems owing to the important roles of HOCl in the immune defense and the pathogenesis of numerous diseases. In this paper, a new p-aminophenylether-based fluorescent probe PAPE-HA was developed for specific detection of HOCl. Probe PAPE-HA could implement the quantitative detection of HOCl ranging from 0 to 1 μM and the detection limit was obtained as low as 1.

Sulfur-Doped CoO Nanoflakes with Loosely Packed Structure Realizing Enhanced Oxygen Evolution Reaction.

The development of active and inexpensive electrocatalysts for the oxygen evolution reaction (OER) to promote water splitting has always been a major challenge. Cobalt-based oxides and sulfides have been actively investigated due to their low cost and high activity. However, the lower intrinsic conductivity of cobalt oxide and the inferior stability of cobalt sulfides still limit their practical application.

Effects of double-atom vacancies on the electronic properties of graphyne: a DFT investigation.

Vacancy defects are one of the key impurities that strongly affect the properties of materials. In the present study, some different double-atom vacancies were introduced into α-graphyne (Gy), βGy, and γGy, depending on their own structural characteristics. Subsequently, density functional theory (DFT) calculations were carried out to evaluate the changes in the structural and electronic properties induced by the double-atom vacancies.

Positive effect of strong acidity on the twist of Aβ fibrils and the counteraction of Aβ N-terminus.

pH is a crucial factor in terms of affecting the aggregation and morphology of β-Amyloid and hence a focus of study. In this study, structural and mechanical properties of a series of models (5, 6, …, 30 layer) of one-fold Aβ fibrils at pH 1.5, 3.

Micro Galvanic Cell To Generate PtO and Extend the Triple-Phase Boundary during Self-Assembly of Pt/C and Nafion for Catalyst Layers of PEMFC.

The self-assembly powder (SAP) with varying Nafion content was synthesized and characterized by XRD, XPS, HRTEM, and mapping. It is observed that the oxygen from oxygen functional groups transfers to the surface of Pt and generate PtO during the process of self-assembly with the mechanism of micro galvanic cell, where Pt, carbon black, and Nafion act as the anode, cathode and electrolyte, respectively. The appearance of PtO on the surface of Pt leads to a turnover of Nafion structure, and therefore more hydrophilic sulfonic groups directly contact with Pt, and thus the triple-phase boundary (TPB) has been expanded.

Bead-Level Characterization of Early-Stage Amyloid β Aggregates: Nuclei and Ionic Concentration Effects.

A growing body of evidence shows that soluble β-amyloid (Aβ) aggregates, oligomers, and even protofibrils, may be more neurotoxic than fibrils. Here, we employ a coarse grain model to investigate the aggregation of 75mer Aβ oligomers and the salt effect, the cornerstone of fibril evolution. We find that the oligomer morphologies generated by seventy-five monomers or mixed by both fifty monomers and five preset pentameric nuclei are different (spherical vs.

N-Terminus Binding Preference for Either Tanshinone or Analogue in Both Inhibition of Amyloid Aggregation and Disaggregation of Preformed Amyloid Fibrils-Toward Introducing a Kind of Novel Anti-Alzheimer Compounds.

Amyloid-β (Aβ/Aβ) peptide with a length of 40 or 42 residues is naturally secreted as cleavage product of the amyloid precursor protein, and formation of Aβ aggregates in a patient's brain is a hallmark of Alzheimer's disease (AD). Therefore, disaggregation and disruption provide potential therapeutic approaches to reduce, inhibit, and even reverse Aβ aggregation. The disaggregation/inhibition effect of the inhibitors applies generally to both Aβ and Aβ aggregations.

Periodicity of band gaps of chiral α-graphyne nanotubes.

Electronic structures of zigzag (n,0), armchair (n,n), and chiral (n,m) α-graphyne nanotubes (αGNTs) with n = 2-7 were investigated using density functional tight binding calculations. Oscillatory behavior of the band gaps with a period of every (n - m) = 3 was found for each tube. According to the periodicity, αGNTs could be classified into three families, and their band gaps were in the increasing order of (n - m) = 3a < 3a + 1 < 3a + 2.

Solvent effect on hydrogen bonded Tyr⋯Asp⋯Arg triads: Enzymatic catalyzed model system.

The hydrogen bond plays a vital role in structural arrangement, intermediate state stabilization, materials function, and biological activity of certain enzymatic reactions. The solvent and electronic effects on hydrogen bonds are illustrated employing the polarizable contimuum model at B3LYP/6-311++G(d,p) level. Geometry optimizations reflect the significant solvent and electronic effect.