다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

The construction of heterostructures is regarded as an excellent strategy to achieve efficient charge separation and improved photocatalytic activity. Herein, a series of Bi2MoO6/ZnO hierarchical heterostructured photocatalysts were synthesized by a solvothermal method. The morphology of Bi2MoO6 grown on the surface of ZnO nanorods could be controlled by adjusting the experimental conditions. The synthesized samples were characterized by various analytical techniques and their photocatalytic performance was evaluated by photocatalytic reduction of Cr(VI) under visible-light irradiation. Compared with those of pure Bi2MoO6 and ZnO, the Bi2MoO6/ZnO composites showed higher photocatalytic activity towards the reduction of Cr(VI). The enhanced photocatalytic activity was mainly attributed to the formation of a heterojunction between Bi2MoO6 and ZnO, which effectively facilitated the separation and transfer of electrons and holes. In addition, the Bi2MoO6/ZnO photocatalysts maintained good stability after three cycles of Cr(VI) photoreduction. A possible photocatalytic mechanism of the as-synthesized composites was proposed.

Fabrication of Bi2MoO6/ZnO hierarchical heterostructures with enhanced visible-light photocatalytic activity

Luminescent carbon quantum dots (CQDs) represent a new form of nanocarbon materials which have gained widespread attention in recent years, especially in chemical sensor, bioimaging, nanomedicine, solar cells, light-emitting diode (LED), and electrocatalysis. CQDs can be prepared simply and inexpensively by multiple techniques, such as the arc-discharge method, microwave pyrolysis, hydrothermal method, and electrochemical synthesis. CQDs show excellent physical and chemical properties like high crystallization, good dispersibility, photoluminescence properties. In particular, the small size, superconductivity, and rapid electron transfer of CQDs endow the CQDs-based composite with improved electric conductivity and catalytic activity. Besides, CQDs have abundant functional groups on the surface which could facilitate the preparation of multi-component electrical active catalysts. The interactions inside these multi-component catalysts may further enhance the catalytic performance by promoting charge transfer which plays an important role in electrochemistry. Most recent researches on CQDs have focused on their fluorescence characteristics and photocatalytic properties. This review will summarize the primary advances of CQDs in the synthetic methods, excellent physical and electronic properties, and application in electrocatalysis, including oxygen reduction reaction (ORR), oxygen evolution reaction (OER), hydrogen evolution reduction (HER), and CO2 reduction reaction (CO2RR).

/pdf/a-mini-review-on-carbon-quantum-dots-preparation-properties-7ft9qrk7un.pdf

A Mini Review on Carbon Quantum Dots: Preparation, Properties, and Electrocatalytic Application.

Cu2O/BiVO4 heterostructures: synthesis and application in simultaneous photocatalytic oxidation of organic dyes and reduction of Cr(VI) under visible light

A series of carbon nanotube (CNTs)-supported copper-cobalt catalysts were prepared and investigated in a slurry reactor for their ability to selectively convert syngas into higher carbon number alcohols. The 7.5Cu7.5Co/CNTs catalyst achieved superior selectivity towards the formation of ethanol (30.1%) and C2+ alcohols (57.7%), while the 10Co5Cu/CNTs catalyst exhibited the largest alcohol space-time yield (372.9 mg gcat -1 h-1). However, the pure Cu (15Cu/CNTs) catalyst displayed negligible activity. Cobalt reduction was enhanced in the presence of copper. In addition to the Cu0-Co0 center, Co0-Co2+ also presented dual active sites for higher alcohols synthesis, the Co2+ site could terminate carbon chain growth to produce alcohols. The ratio of Cu/Co considerably influences the metal particle properties-synergistically effecting the active species.

/pdf/carbon-nanotube-supported-copper-cobalt-catalyst-for-the-3q4oynl8hl.pdf

Carbon Nanotube-Supported Copper-Cobalt Catalyst for the Production of Higher Carbon Number Alcohols through Carbon Monoxide Hydrogenation

Synthesis and study of Bi2Ti2O7/TiO2 composites as efficient visible-light-active photocatalysts in the reduction of aqueous Cr(VI)

Corrugated rGO-supported Pd composite on carbon paper for efficient cathode of Mg-H2O2 semi-fuel cell

Covalent organic frameworks are unique for their highly open architecture and attractive for use as promising gas adsorption and storage carriers. In this work, density functional theory calculations have been performed to investigate the properties of metal-doped covalent organic frameworks and their interactions with the SO2 gas molecule. It is found that a single metal atom (including Li, Na, K, and Sc) doped at the top of phenyls within the tetra(4-dihydroxyborylphenyl) silane (TBPS) building block of covalent organic frameworks can easily lose its valence electrons and can be positively charged. The SO2 gas molecule could be stably absorbed onto the metal-doped covalent organic frameworks. The absorbed SO2 molecule interacts with Li, Na, K, and Sc metal-doped covalent organic frameworks by the dominant donor-acceptor delocalization between 1-center lone pair of an oxygen atom within SO2 and 1-center non-Lewis lone pairs of the doped metal atom.

/pdf/properties-of-metal-doped-covalent-organic-frameworks-and-33r1msktsf.pdf

Properties of Metal-Doped Covalent Organic Frameworks and Their Interactions with Sulfur Dioxide

A series of carbon nanotubes (CNTs)-supported cobalt–ceria catalysts were designed, synthesized, and tested in a fixed-bed reactor for selectively converting syngas into higher alcohols and long chain hydrocarbons. In order to investigate the synergistic effect of cobalt and ceria, different geometric structures of Co-CeO2–x were adjusted and designed by using the confinement effects of nanotubes and catalyst loading amounts. The selectivities for the production of C2+ alcohols and ethanol using 10Co10Ce/CNTs were 67.0% and 38.4%, respectively, among the alcohol distribution. CeO2–x effectively provided sites for regulating the ratio of Co0/Coδ+ in the cobalt particles. The intimate contact between cobalt and ceria species in the CNT channels was favorable for the synthesis of higher alcohols. However, the separation of the Co-CeO2–x sites on the exterior surface of CNTs could weaken the synergistic effect of the two sites, increase Co0 content in metallic-oxide Co pairs, and thus, lead to the formation of long-chain hydrocarbons. The products could be effectively controlled by adjusting and reconstructing the geometric structure of Co and CeO2 sites. 

Xihua Du

Papers

Carbon Nanotube-Supported Copper-Cobalt Catalyst for the Production of Higher Carbon Number Alcohols through Carbon Monoxide Hydrogenation

Synthesis and study of Bi2Ti2O7/TiO2 composites as efficient visible-light-active photocatalysts in the reduction of aqueous Cr(VI)

Corrugated rGO-supported Pd composite on carbon paper for efficient cathode of Mg-H2O2 semi-fuel cell

Properties of Metal-Doped Covalent Organic Frameworks and Their Interactions with Sulfur Dioxide

Study on the Synergistic Catalysis of CeO2 Regulated Co0–Coδ+ Dual Sites for Direct Synthesis of Higher Alcohols from Syngas