Accelerated anti-Markovnikov alkene hydrosilylation with humic-acid-supported electron deficient platinum single atoms

Hydrosilylation reaction is one of the largest-scale applications of homogeneous catalysis, and Pt homogeneous catalyst has been widely used in this reaction for the commercial manufacture of silicon products. However, homogeneous Pt catalysts results in considerable problems, such as undesired side reactions, unacceptable catalyst residues and disposable platinum consumption. Here, we synthesized electron deficient Pt single atoms supported on humic matter (Pt1@AHA\_U\_400), and the catalyst was used in hydrosilylation reaction, which showed super activity (turnover frequency as high as 3.0 × 107 h-1) and selectivity (>99%). Density functional theory calculations reveal that the high performance of the catalyst results from the atomic dispersion of Pt and the electron deficiency of the Pt1 atoms, which is different from conventional Pt nanoscale catalysts. Excellent performance is maintained during recycle experiments, indicating the high stability of the catalyst

Patching laser-reduced graphene oxide with carbon nanodots

Three-dimensional graphenes are versatile materials for a range of electronic applications and considered among the most promising candidates for electrodes in future electric double layer capacitors (EDLCs) as they are expected to outperform commercially used activated carbon. Parameters such as electrical conductivity and active surface area are critical to the final device performance. By adding carbon nanodots to graphene oxide in the starting material for our standard laser-assisted reduction process, the structural integrity (i.e. lower defect density) of the final 3D-graphene is improved. As a result, the active surface area in the hybrid starting materials was increased by 130% and the electrical conductivity enhanced by nearly an order of magnitude compared to pure laser-reduced graphene oxide. These improved material parameters lead to enhanced device performance of the EDLC electrodes. The frequency response, i.e. the minimum phase angle and the relaxation time, were significantly improved from −82.2° and 128 ms to −84.3° and 7.6 ms, respectively. For the same devices the specific gravimetric device capacitance was increased from 110 to a maximum value of 214 F g−1 at a scan rate of 10 mV s−1

Green Light Photoelectrocatalysis with Sulfur-Doped Carbon Nitride: Using Triazole-Purpald for Enhanced Benzylamine Oxidation and Oxygen Evolution Reactions

Materials dictate carbon neutral industrial chemical processes. Visible-light photoelectrocatalysts from abundant resources will play a key role in exploiting solar irradiation. Anionic doping via pre-organization of precursors and further co-polymerization creates tuneable semiconductors. Triazole derivative-purpald, an unexplored precursor with sulfur (S) container, combined in different initial ratios with melamine during one solid-state polycondensation with two thermal steps yields hybrid S-doped carbon nitrides (C3N4). The series of S-doped/C3N4-based materials show enhanced optical, electronic, structural, textural, and morphological properties and exhibit higher performance in organic benzylamine photooxidation, oxygen evolution, and similar energy storage (capacitor brief investigation). 50M-50P exhibits the highest photooxidation conversion (84 ± 3%) of benzylamine to imine at 535 nm – green light for 48 h, due to a discrete shoulder (≈700) nm, high sulfur content, preservation of crystal size, new intraband energy states, structural defects by layer distortion, and 10–16 nm pores with arbitrary depth. This work innovates by studying the concomitant relationships between: 1) the precursor decomposition while C3N4 is formed, 2) the insertion of S impurities, 3) the S-doped C3N4 property-activity relationships, and 4) combinatorial surface, bulk, structural, optical, and electronic characterization analysis. This work contributes to the development of disordered long-visible-light photocatalysts for solar energy conversion and storage

Green light photoelectrocatalysis with sulfur-doped carbon nitride : using triazole-purpald for enhanced benzylamine oxidation and oxygen evolution reactions

Novel high performing materials will dictate the pace of reinventing industrial chemical processes to attain desired carbon neutrality targets. Regarding the urgency of exploiting solar irradiation long range visible-light photoelectrocatalysts from abundant resources will play a key role in the aforementioned effort. Anionic doping via co-polymerization and pre-organization of precursors results in tuneable and extrinsic semiconductors, making this a highly attractive methodology. Triazole derivative-purpald, an unexplored precursor but sulfur (S) container, combined with melamine during one solid-state polycondensation reaction with two thermal steps leads to S-doped carbon nitrides (C34). The series of S-doped/CN4-based materials demonstrated enhanced optical, electronic, structural, geometric, textural, and morphological properties and exhibited higher performance in organic benzylamine photooxidation, oxygen evolution, and similar storing energy (capacitor brief investigation) than references. Among the five composites, 50M-50P exhibited the highest photooxidation conversion yield (84±3%) of benzylamine to imine at 535 nm – green light for 48h, due to an extra discrete shoulder reaching ~700 nm, an unusual high sulfur content, preservation of crystal size, new intraband energy states, rare deep structural defects by layer distortion, hydrophobic surface, low porosity, and 10-16 nm pores. An in-depth analysis of S doping was investigated coupling x-ray photoelectron spectroscopy, transmission electron microscope, and elemental analysis, providing insights on bonds, distribution, and surface/bulk content. This work contributes to the development of amorphous photocatalysts with long-visible-light range for solar energy conversion and storage

Green Light Photoelectrocatalysis with Sulfur Doped Carbon Nitride Using Triazole Purpald for Enhanced Benzylamine Oxidation and Oxygen Evolution Reactions

Materials dictate carbon neutral industrial chemical processes. Visible light photoelectrocatalysts from abundant resources will play a key role in exploiting solar irradiation. Anionic doping via pre organization of precursors and further co polymerization creates tuneable semiconductors. Triazole derivative purpald, an unexplored precursor with sulfur S container, combined in different initial ratios with melamine during one solid state polycondensation with two thermal steps yields hybrid S doped carbon nitrides C3N4 . The series of S doped C3N4 based materials show enhanced optical, electronic, structural, textural, and morphological properties and exhibit higher performance in organic benzylamine photooxidation, oxygen evolution, and similar energy storage capacitor brief investigation . 50M 50P exhibits the highest photooxidation conversion 84 3 of benzylamine to imine at 535 nm green light for 48 h, due to a discrete shoulder amp; 8776;700 nm, high sulfur content, preservation of crystal size, new intraband energy states, structural defects by layer distortion, and 10 16 nm pores with arbitrary depth. This work innovates by studying the concomitant relationships between 1 the precursor decomposition while C3N4 is formed, 2 the insertion of S impurities, 3 the S doped C3N4 property activity relationships, and 4 combinatorial surface, bulk, structural, optical, and electronic characterization analysis. This work contributes to the development of disordered long visible light photocatalysts for solar energy conversion and storag

Limits of Calcium Clearance by Plasma Membrane Calcium ATPase in Olfactory Cilia

BACKGROUND: In any fine sensory organelle, a small influx of Ca(2+) can quickly elevate cytoplasmic Ca(2+). Mechanisms must exist to clear the ciliary Ca(2+) before it reaches toxic levels. One such organelle has been well studied: the vertebrate olfactory cilium. Recent studies have suggested that clearance from the olfactory cilium is mediated in part by plasma membrane Ca(2+)-ATPase (PMCA). PRINCIPAL FINDINGS: In the present study, electrophysiological assays were devised to monitor cytoplasmic free Ca(2+) in single frog olfactory cilia. Ca(2+) was allowed to enter isolated cilia, either through the detached end or through membrane channels. Intraciliary Ca(2+) was monitored via the activity of ciliary Ca(2+)-gated Cl(-) channels, which are sensitive to free Ca(2+) from about 2 to 10 microM. No significant effect of MgATP on intraciliary free Ca(2+) could be found. Carboxyeosin, which has been used to inhibit PMCA, was found to substantially increase a ciliary transduction current activated by cyclic AMP. This increase was ATP-independent. CONCLUSIONS: Alternative explanations are suggested for two previous experiments taken to support a role for PMCA in ciliary Ca(2+) clearance. It is concluded that PMCA in the cilium plays a very limited role in clearing the micromolar levels of intraciliary Ca(2+) produced during the odor response

Разнообразие насекомых и других членистоногих в Монголии

The insect fauna of Mongolia includes about 12,000 species belonging to 2

Problems and perspectives of public administration reform : the case of the executive branch of the government of Mongolia

Mongolia;administrative reform

Water acting as a catalytic promoter for electron-proton transfer in the Pt single atom catalyzed environmental reduction reactions

Water, which is the host of life, introduces many unusual features into the kinetics and energetics of biological reaction systems catalyzed by enzymes. Single atom catalyst has great potential to mimic biological enzymes in regard to special catalytic sites and high efficiency. Here we report a significant promotion by H2O in the environmental reduction of nitrobenzene on an environmentally friendly humic acid supported Pt single atom catalyst. No nitrobenzene conversion took place when only organic solvents were used while high activity of the catalyst was observed in aqueous mixtures (turnover frequency is as high as 1883 h−1). Experiments and density functional theory calculation show that H2O greatly decreased the energy barrier by enabling a biomimetic electron-proton transfer for the hydrogenation process even on single atom Pt catalyst, and a new reaction pathway with phenyl-λ1-azane as intermediate in the direct hydrogenation of nitrobenzene is proposed