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fluorinated Covalent Organic Frameworks Coupled with Molecular Cobalt Cocatalysts for Efficient Photocatalytic CO_(2)Reduction

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CCS Chemistry 2023年第10期5卷 2290-2300页

作者： Zhiwei Fu Chang Shu Xiaoyan Wang Linjiang Chen Xue Wang Lunjie Liu Kewei Wang Rob Clowes Samantha Y.Chong Xiaofeng Wu Andrew I.Cooper Department of Chemistry and Materials Innovation Factory University of LiverpoolLiverpool L73NY Key Laboratory of Material Chemistry for Energy Conversion and Storage Ministry of EducationHubei Key Laboratory of Material Chemistry and Service FailureSchool of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhanHubei 430074 School of Chemistry and School of Computer Science University of BirminghamBirmingham B152TT Leverhulme Research Centre for Functional Materials Design University of LiverpoolLiverpool L73NY Department of Chemistry and Chemical Engineering Shanxi Datong UniversityDatong 037009

The combination of covalent organic framework(COF)photosensitizers with molecular cocatalysts is a promising avenue for photocatalytic carbon dioxide(CO_(2))reduction.Here,a series of isostructural COFs was synthesized using linkers of different lengths,with or without partial fluorination.These COFs were investigated for photocatalytic CO_(2)reduction under visible-light irradiation when combined with cobalt(II)bipyridine complexes as a cocatalyst.Fluorination was found to enhance both CO_(2)affinity and catalytic activity,and a partially fluorinated COF,FBP-COF,achieved the highest CO_(2)-to-CO conversion efficiency,showing a carbon monoxide(CO)generation rate of 2.08 mmol h−1 g−1 and a 90%CO selectivity.FBP-COF also showed good stability under sacrificial conditions,generating CO for 50 h with a turnover number of 91.5.This activity is much higher than a homogeneous system using ruthenium bipyridine complexes as the photosensitizer combined with the same cobalt bipyridine complexes.

关键词： carbon dioxide conversion photocatalysis covalent organic frameworks fluorinated solar energy conversion

Synthesis of amphiphilic fluorinated Janus particles with applications in stabilizing surfactant-free foams

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Particuology 2018年第6期16卷 112-117页

作者： Gang Wang Keliang Wang Ying Wang Ministry of Education Key Laboratory of Enhanced Oil Recovery Technology Northeast Petroleum UniversityDaqing 163318China State Key Laboratory oflnorganic Synthesis &Preparative Chemistry Jilin UniversityChangchun 130012China

We report the preparation of amphiphilic Janus particles covered with fluorinated chains as well as the self-assembly and foam stabilization property of these particles over a limited range of concentrations.The structure and properties of these particles were characterized using scanning electron microscopy,Fourier transform infrared spectroscopy,fluorescence microscopy,pendant drop tensiometer,and foamscan.At a particle concentration of 0.6wt%,the adsorption of the Janus particles at the interface was saturated and an equilibrium surface tension of approximately 35mN/m was obtained. No further decreases in surface tension were observed with additional increases in the particle concentration.At a concentration of 0.4wt%,the Gibbs stability criterion was achieved and the foam volume was almost constant throughout the observation period.Additionally,the liquid fraction of the foam exhibited a static equilibrium at each concentration assessed,demonstrating that drainage was arrested effectively.These results confirm that the use of amphiphilic Janus particles is an efficient approach to stabilizing foams.

关键词： Janus particle fluorinated grafting agent Amphiphilic particle Self-assembly Dynamic surface tension Foam stability

Exploring high-voltage fluorinated carbonate electrolytes for LiNi0.5Mn1.5O4 cathode in Li-ion batteries

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Journal of Energy Chemistry 2020年第3期29卷 62-70页

作者： Xi Zheng Ying Liao Zhongru Zhang Jianping Zhu Fucheng Ren Huajin He Yuxuan Xiang Yezhen Zheng Y.Yang State Key Laboratory for Physical Chemistry of Solid Surfaces Collaborative Innovation Center of Chemistry for Energy Materials(iChEM)and Department of ChemistryCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005FujianChina College of Energy Xiamen UniversityXiamen 361102FujianChina

Ethyl-(2,2,2-trifluoroethyl)carbonate(ETFEC)is investigated as a solvent component in high-voltage electrolytes for LiNi0.5Mn1.5O4(LNMO).Our results show that the self-discharge behavior and the high temperature cycle performance can be significantly improved by the addition of 10%ETFEC into the normal carbonate electrolytes,e.g.,the capacity retention improved from 65.3%to 77.1%after 200 cycles at 60℃.The main reason can be ascribed to the high stability of ETFEC which prevents large oxidation of the electrolyte on the cathode surface.In addition,we also explore the feasibility of electrolytes using single fluoriated-solvents with and without additives.Our results show that the cycle performance of LNMO material can be greatly improved in 1 MLiPF6+pure ETFEC-solvent system with 2 wt%ethylene carbonate(EC)or ethylene sulfate(DTD).The capacity retention of the LNMO materials is 93%after 300 cycles,even better than that of carbonate-based electrolytes.It is shown that the additives are oxidized on the surface of LNMO particles and contribute to the formation of cathode/electrolyte interphase(CEI)films.This composite CEI film plays a crucial role in suppressing the serious decomposition of the electrolyte at high voltage.

关键词： fluorinated solvent High voltage electrolyte LiNi0.5Mn1.5O4 Interphase film Additive Lithium-ion batteries

Recent progress in fluorinated electrolytes for improving the performance of Li–S batteries

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Journal of Energy Chemistry 2020年第2期29卷 149-170页

作者： Xiwen Wang Yuqing Tan Guohong Shen Shiguo Zhang College of Materials Science and Engineering State Key Laboratory of Advanced Design and Manufacturing for Vehicle BodyHunan UniversityChangsha 410082HunanChina

Lithium–sulfur(Li–S) batteries represent a "beyond Li-ion" technology with low cost and high theoretical energy density and should fulfill the ever-growing requirements of electric vehicles and stationary energy storage systems. However, the sulfur-based conversion reaction in conventional liquid electrolytes results in issues like the so-called shuttle effect of polysulfides and lithium dendrite growth, which deteriorate the electrochemical performance and safety of Li–S batteries. Optimization of conventional organic solvents(including ether and carbonate) by fluorination to form fluorinated electrolytes is a promising strategy for the practical application of Li–S batteries. The fluorinated electrolytes, owing to the high electronegativity of fluorine, possesses attractive physicochemical properties, including low melting point,high flash point, and low solubility of lithium polysulfide, and can form a compact and stable solid electrolyte interphase(SEI) with the lithium metal anode. Herein, we review recent advancements in the development of fluorinated electrolytes for use in Li–S batteries. The effect of solvent molecular structure on the performance of Li–S batteries and the formation mechanism of SEI on the cathode and anode sides are analyzed and discussed in detail. The remaining challenges and future perspectives of fluorinated electrolytes for Li–S batteries are also presented.

关键词： Lithium–sulfur batteries Electrolyte fluorinated solvents Shuttle effect SEI forming mechanism

Progress of synthesizing methods and properties of fluorinated carbon nanotubes

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Science China(Technological Sciences) 2010年第5期53卷 1225-1233页

作者： LI Yu1,2,CHEN YanFang1,2,FENG YiYu1,2,ZHAO ShengLing1,2,Lü Peng1,2,YUAN XiaoYan1,2 & FENG Wei1,2 1School of Materials Science and Engineering,Tianjin University,Tianjin 300072,China 2Tianjin Key Laboratory of Composite and Functional Materials,Tianjin 30072,China School of Materials Science and Engineering Tianjin University Tianjin China Tianjin Key Laboratory of Composite and Functional Materials Tianjin China

In this paper,the recent development of fluorinated carbon nanotubes(F-CNTs) was introduced.The synthesizing methods of F-CNTs,including direct fluorination and plasma treatment,were discussed in detail,and the effects of factors,such as the temperature and pressure in fluorination as well as the kind of fluorine source and carbon nanotubes,on the structures and properties of F-CNTs were also summarized.In the mean time,the special physical and chemical properties of F-CNTs and the relevant applied fields were described briefly,the exisiting problems of F-CNTs were summed up,and the direction of future development was also discussed in the end.

关键词： carbon nanotubes fluorination plasma treatment fluorinated carbon nanotubes substitution reaction

Synthesis and characterization of fluorinated PEO-b-PDMS-b-fluorinated PEO by free radical addition

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Chinese Chemical Letters 2009年第9期20卷 1127-1130页

作者： Wei Hu Li Xing Yuan Zhang Jia Bing Dai CAS Key Laboratory of Soft Matter Chemistry Department of Polymer Science and Engineering University of Science and Technology of China Hefei 230026 China

fluorinated poly（ethylene oxide） propyl-b-polydimethylsiloxane-b-propyl fluorinated poly（ethylene oxide）（FPEO-b-PDMS-b- FPEO） was synthesized by a free radical addition of carbon-hydrogen of polyether segments of poly（ethylene oxide） propyl-b- polydimethylsiloxane-b-propyl poty（ethylene oxide）（PEO-b-PDMS-b-PEO） to hexafluoropropylene （HFP） using tert-butyl peroxypivalate as an initiator. In order to reduce the possibility of side reaction, the protection and deprotection via silylation were used for the end-hydroxyls in PEO-b-PDMS-b-PEO chain. The structure of Intermediates and FPEO-b-PDMS-b-FPEO was confirmed by means of Fourier transform infrared and 1H NMR spectroscopy. The effects of amount of initiator, reaction temperature and time on free radical addition were investigated in detail. 2009 Xing Yuan Zhang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

关键词： fluorinated Hexafluoropropylene Polydimethylsiloxane Free radical addition Silylation

Design and synthesis of the novel branched fluorinated surfactant intermediates with CF_3CF_2CF_2C(CF_3)_2 group

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Chinese Chemical Letters 2019年第3期30卷 566-568页

作者： Ding Zhang Min Sha Renming Pan Xiangyang Lin Ping Xing Biao Jiang School of Chemical Engineering Nanjing University of Science and Technology CAS Key Laboratory of Synthetic Chemistry of Natural Substances Shanghai Institute of Organic Chemistry Chinese Academy of Sciences School of Management Science & Engineering Nanjing University of Finance & Economics

Perfluorooctanoic acid(PFOA) or perfluorooctane sulphonate(PFOS) was one of the most prominent fluorosurfactants and applied widely in firefighting and daily chemical, etc. However, these surfactants have recently been identified as toxic and undegradability in the environment. Developing an efficient approach to environment-friendly fluorosurfactants is essential. A fluorocarbon branched chain strategy was adopted to develop/PFOS substitutes. A series of intermediates of novel branched fluorinated surfactants with CF_3 CF_2CF_2C(CF3)_2 group were synthesized from perfluoro-2-methyl-2-pentene. All the steps were mild, easy-handled and cheap. It is expected to be a very significant direction for the development of non-bioaccumulable alternatives of PFOA or PFOS.

关键词： Perfluoro-2-methyl-2-pentene Branched fluorinated surfactants Oxy fluorocarbon chain

Asymmetric Synthesis of fluorinated Vicinal Diamines from Fluoromethyl Sulfinyl Imines and Diphenylmethylene-Benzylamines

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Journal of Donghua University(English Edition) 2016年第3期33卷 358-365页

作者：何杰杰李光锋孟卫东黄焰根 College of Chemistry Chemical Engineering and BiotechnologyDonghua University

A novel strategy was developed for the asymmetric synthesis of fluorinated vicinal diamines.Deprotonation of N-(diphenylmethylene)-benzylamines under base,followed by asymmetric nucleophilic addition to N-tert-butanesulfinylfluoroacetaldimines,a pair of diastereomeric isomers were afforded.The diastereomeric isomers can be easily separated from each other by silica gel column chromatography.The absolute steric configuration of two isomers was confirmed by single crystal X-ray diffraction analyses.The proposed mechanism revealed that the configuration of the carbon next to tert-butanesulfinyl was well controlled to be R by the chiral auxiliary.

关键词： tert-butanesulfinyl vicinal diamine nucleophilic addition diastereoselectivity fluorinated

fluorinated Surfactants and fluorinated Polymer Materials(Ⅲ): Personal Opinion on the Problems of PFOS

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China Detergent & Cosmetics 2019年第3期4卷 54-62页

作者： Xing Hang Dou Zengpei Xiao Zibing Xiao Jinxin Beijing FLUOBON Surfactant Institute

As surfactant researchers, we have discussed the current problems of PFOS in China from our personal standpoint. The difficulties in both elimination and investigation on PFOS are analyzed. The production, application, biodegradation and regulation for some other important fluorinated alkylated substances are also briefly introduced. Finally, the objective and tasks for surfactant researchers are pointed out.

关键词： fluorinated surfactant fluoropolymer PFOS POPs PFOA