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

Evaluation of advanced oxidation processes for water and wastewater treatment - A critical review.

Reports that promote persulfate-based advanced oxidation process (AOP) as a viable alternative to hydrogen peroxide-based processes have been rapidly accumulating in recent water treatment literature. Various strategies to activate peroxide bonds in persulfate precursors have been proposed and the capacity to degrade a wide range of organic pollutants has been demonstrated. Compared to traditional AOPs in which hydroxyl radical serves as the main oxidant, persulfate-based AOPs have been claimed to involve different in situ generated oxidants such as sulfate radical and singlet oxygen as well as nonradical oxidation pathways. However, there exist controversial observations and interpretations around some of these claims, challenging robust scientific progress of this technology toward practical use. This Critical Review comparatively examines the activation mechanisms of peroxymonosulfate and peroxydisulfate and the formation pathways of oxidizing species. Properties of the main oxidizing species are scrutinized and the role of singlet oxygen is debated. In addition, the impacts of water parameters and constituents such as pH, background organic matter, halide, phosphate, and carbonate on persulfate-driven chemistry are discussed. The opportunity for niche applications is also presented, emphasizing the need for parallel efforts to remove currently prevalent knowledge roadblocks.

/pdf/persulfate-based-advanced-oxidation-critical-assessment-of-ru3om4hbrg.pdf

Persulfate-Based Advanced Oxidation: Critical Assessment of Opportunities and Roadblocks.

The use of zero-valent iron for groundwater remediation and wastewater treatment: a review.

The present review is devoted to summarizing the recent advances (2015-2017) in the field of metal-catalysed group-directed C-H functionalisation In order to clearly showcase the molecular diversity that can now be accessed by means of directed C-H functionalisation, the whole is organized following the directing groups installed on a substrate Its aim is to be a comprehensive reference work, where a specific directing group can be easily found, together with the transformations which have been carried out with it Hence, the primary format of this review is schemes accompanied with a concise explanatory text, in which the directing groups are ordered in sections according to their chemical structure The schemes feature typical substrates used, the products obtained as well as the required reaction conditions Importantly, each example is commented on with respect to the most important positive features and drawbacks, on aspects such as selectivity, substrate scope, reaction conditions, directing group removal, and greenness The targeted readership are both experts in the field of C-H functionalisation chemistry (to provide a comprehensive overview of the progress made in the last years) and, even more so, all organic chemists who want to introduce the C-H functionalisation way of thinking for a design of straightforward, efficient and step-economic synthetic routes towards molecules of interest to them Accordingly, this review should be of particular interest also for scientists from industrial R&D sector Hence, the overall goal of this review is to promote the application of C-H functionalisation reactions outside the research groups dedicated to method development and establishing it as a valuable reaction archetype in contemporary R&D, comparable to the role cross-coupling reactions play to date

/pdf/a-comprehensive-overview-of-directing-groups-applied-in-543u6d0g60.pdf

A comprehensive overview of directing groups applied in metal-catalysed C-H functionalisation chemistry.

NiS2@CoS2 nanocrystals encapsulated in N-doped carbon nanocubes for high performance lithium/sodium ion batteries

Designing metal-free g-C3N4 based photocatalytic system with efficient photocatalytic activity has received enormous attention in the field of environmental remediation because of its great potential for removing refractory contaminants. Herein, a novel metal organic framework (ZIF-8)-derived nitrogen doped carbon (ZIF-NC) modified g-C3N4 heterostructured composite was synthesized through a facile thermal treatment method. Benefiting from the hierarchical porosity, conductive network, and abundant exposed active sites for peroxymonosulfate (PMS) activation of MOF-derived nitrogen doped carbon, the introduction of MOF-derived nitrogen doped carbon into g-C3N4 not only facilitates the charge separation of g-C3N4 but also greatly accelerates PMS activation to yield high active SO4 − radical. The energy band diagrams derived from Mott-Schottky, valence band X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy studies indicate that the formed heterojunction between g-C3N4 and ZIF-NC is Schottky type. The ZIF-NC with lower Fermi level energy can serve as an excellent electron accepter to enable fast electron transfer from the conduction band of g-C3N4 to ZIF-NC and boost the charge separation of g-C3N4. Photoelectrochemical tests combined with multiple spectroscopic techniques further confirm the enhanced charge carrier separation performance of composite. As a result, the as-prepared hybrids displayed remarkably improved photocatalytic activities toward bisphenol A (BPA) degradation in the presence of PMS under visible light irradiation. The apparent rate constant, k, for BPA degradation of the ZIF-NC/g-C3N4 composites with PMS is approximately 8.6 times as high as that of bare g-C3N4. This work provides a promising approach on the rational design of high-performance, cost-effective photocatalysts for environmental remediation.

MOF-derived nitrogen doped carbon modified g-C3N4 heterostructure composite with enhanced photocatalytic activity for bisphenol A degradation with peroxymonosulfate under visible light irradiation

The electrochemical decomposition of persistent perfluorooctanoate (PFOA) with a Ti/SnO2-Sb-Bi electrode was demonstrated in this study. After 2 h electrolysis, over 99% of PFOA (25 mL of 50 mg·L(-1)) was degraded with a first-order kinetic constant of 1.93 h(-1). The intermediate products including short-chain perfluorocarboxyl anions (CF3COO-, C2F5COO-, C3F7COO-, C4F9COO-, C5F11COO-, and C6F13COO-) and F- were detected in the aqueous solution. The electrochemical oxidation mechanism was revealed, that PFOA decomposition first occurred through a direct one electron transfer from the carboxyl group in PFOA to the anode at the potential of 3.37 V (vs saturated calomel electrode, SCE). After that, the PFOA radical was decarboxylated to form perfluoroheptyl radical which allowed a defluorination reaction between perfluoroheptyl radical and hydroxyl radical/O2. Electrospray ionization (ESI) mass spectrum further confirmed that the oxidation of PFOA on the Ti/SnO2-Sb-Bi electrode proceeded from the carboxyl group in PFOA rather than C-C cleavage, and the decomposition processes followed the CF2 unzipping cycle. The electrochemical technique with the Ti/SnO2-Sb-Bi electrode provided a potential method for PFOA degradation in the aqueous solution.

Bo Yang

Papers

NiS2@CoS2 nanocrystals encapsulated in N-doped carbon nanocubes for high performance lithium/sodium ion batteries

MOF-derived nitrogen doped carbon modified g-C3N4 heterostructure composite with enhanced photocatalytic activity for bisphenol A degradation with peroxymonosulfate under visible light irradiation

Efficient electrochemical oxidation of perfluorooctanoate using a Ti/SnO2-Sb-Bi anode.

Single Ru Atoms Stabilized by Hybrid Amorphous/Crystalline FeCoNi Layered Double Hydroxide for Ultraefficient Oxygen Evolution

Degradation of perfluorinated compounds on a boron-doped diamond electrode