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Hollow spherical titanium dioxide nanoparticles for energy and environmental applications

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Particuology 2015年第5期13卷 13-23页

作者： Peng Zhang Ang Li Jinlong Gong Key Laboratory for Green chemical Technology of Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityCollaborative Innovation Center of Chemical Science and Engineering

Hollow spherical titanium dioxide （TiO2） nanoparticles possess unique properties toward energy and environmental applications, because of the intrinsic properties of TiO2 and benefits induced by their hollow structure. A detailed understanding of TiO2 hollow spheres will promote their use in sustainable energy and environmental applications. This perspective details current methods for synthesizing hollow spherical TiO2 nanoparticles, and their performance in dye-sensitized solar cells, photocatalysts, and batteries. This perspective will promote the design and innovative thinking on the application of hollow spherical metal oxide nanooarticles.

关键词： TiO2 Hollow sphere Dye-sensitized solar cell Photocatalyst Battery

Enhanced catalytic conversion of polysulfides using high-percentage 1T-phase metallic WS_(2) nanosheets for Li–S batteries

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Green Energy & Environment 2022年第6期7卷 1340-1348页

作者： Changyu Yang Ning Gong Tao Chen Yang Li Wenchao Peng Fengbao Zhang Xiaobin Fan School of chemical engineering and Technology State Key Laboratory of Chemical EngineeringCollaborative Innovation Center of Chemical Science and EngineeringTianjin UniversityTianjin300072China

High-energy-density lithium-sulfur batteries has attracted substantial attention as competitive candidates for large-scale energy storage ***,the adverse“shuttle effect”and sluggish sulfur conversion reaction kinetics immensely obstruct their commercial ***,a two-dimensional metallic 1T phase WS_(2)(1T-WS_(2))nanosheets modified functional separator is developed to improve the electrochemical ***,the semiconducting bulk-WS_(2) crystals,and 2H phase WS_(2)(2H-WS_(2))nanosheets with more basal-plane Svacancy defects are also prepared to probe the contributions of the crystal structure(phase),S-vacancy defects,and edges to the Li–S batteries performance experimentally and *** merits of the synergistic effect of high ion and electron conductivity,enhanced binding ability to lithium polysulfides(LiPSs),and sufficient electrocatalytic active sites,the 1T-WS_(2) shows highly efficient electrocatalysis of LiPSs conversion and further improves Li–S battery *** expected,thus-fabricated cells with 1T-WS_(2) nanosheets present superior cycle stability that maintain capacity decline of 0.039%per cycle after 1000 cycles at 1.0 *** strategy presented here offers a viable approach to reveal the critical factors for LiPSs catalytic conversion,which is beneficial to developing advanced Li–S batteries with enhanced properties.

关键词： Li-S batteries Electrocatalysts Polysulfides WS_(2)

Negative effect on molecular planarity to achieve organic ternary memory: triphenylamine as the spacer

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science China Chemistry 2016年第6期59卷 692-698页

作者： Shugang Xia Jinghui He Hua Li Qingfeng Xu Najun Li Dongyun Chen Jianmei Lu College of Chemistry Chemical Engineering and Materials ScienceCollaborative Innovation Center of Suzhou Nano Science and TechnologySoochow University

Adjusting the spacers between the electron-acceptor and the elector-donor is important to design organic ternary memory material but rarely reported. In this paper, two small molecules, ZIPGA and ZIPCAD with benzene ring or triphenylamine as the spacers, were designed and synthesized to fabricate memory devices. The A1/ZIPGA/indium-tin oxide （ITO） device showed ternary characteristics, whereas A1/ZIPCAD/ITO had no obvious memory characteristics. Density functional theory calculation, X-ray diffraction （XRD） and atomic force microscopy （AFM） were employed to interpret the different memory properties. ZIPGA thin film has the closer intermolecular packing and flatter surface morphology than ZIPCAD film, which was favorable to the electron migration. This work demonstrates the importance of spacers and reveals that triphenylamine may be not a good spacer in design of new memory material.

关键词： small molecules different spacers ternary memory device molecular stacking

Active sites in CO2 hydrogenation over confined VOx-Rh catalysts

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science China Chemistry 2019年第12期62卷 1710-1719页

作者： Guishuo Wang Ran Luo Chengsheng Yang Jimin Song Chuanye Xiong Hao Tian Zhi-Jian Zhao Rentao Mu Jinlong Gong Key Laboratory for Green chemical Technology of Ministry of Education School of Chemical Engineering and Technology Tianjin UniversityCollaborative Innovation Center of Chemical Science and Engineering

Metal oxide-promoted Rh-based catalysts have been widely used for CO2hydrogenation,especially for the ethanol ***,this reaction usually suffers low CO2conversion and alcohols selectivity due to the formation of byproducts methane and *** paper describes an efficient vanadium oxide promoted Rh-based catalysts confined in mesopore *** Rh-0.3VOx/MCM-41 catalyst shows superior conversion（～12%）and ethanol selectivity（～24%）for *** promoting effect can be attributed to the synergism of high Rh dispersion by the confinement effect of MCM-41 and the formation of VOx-Rh interface *** and theoretical results indicate the formation of til-CO at VOx-Rh interface sites is easily dissociated into*CHx,and then*CHxcan be inserted by CO to form CH3CO*,followed by CH3CO*hydrogenation to ethanol.

关键词： interfacial active sites CO2 hydrogenation ethanol Rh-based catalysts confined catalysts

Application of Dual Throttling Air-Conditioning System to Explosion-Proof Frequency Converter

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Transactions of Tianjin University 2015年第2期21卷 95-103页

作者：张于峰高岩盛颖 School of Environmental science and engineering Tianjin University collaborative innovation center of chemical science and engineering

An explosion-proof dual throttling air-conditioning system was put forward to solve the heat dissipation and internal dewing problems of explosion-proof frequency converter in the underground coal mine. This study investigated the feasibility and benefits of explosion-proof dual throttling cooling and dehumidification air-conditioning system applied to the explosion-proof frequency converter. The physical model of dual throttling air-conditioning system was established and its performance parameter was described by mathematical method. The design calculation of the system has also been done. The experimental result showed that the system reached the steady state at the refrigeration mode after running 45 min, and the maximum internal temperature of the flame-proof cavity was 31.0 ℃. The system reached the steady state at the dehumidification mode after running 37 min. The maximum internal relative humidity and temperature of the flame-proof cavity were 33.4% and 36.3 ℃, respectively. Therefore, the proposed system had excellent ability of heat dissipation and avoided internal dewing. Compared with water cooling system, it was more energy-saving and economical. The airflow field of dual throttling air-conditioning system was also studied by CFD simulation. It was found that the result of CFD numerical simulation was highly consistent with the experimental data.

关键词： explosion-proof converter dual throttling air-conditioning CFD energy saving heat dissipation dewing

Control structure comparison for three-product Petlyuk column

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Chinese Journal of chemical engineering 2018年第8期26卷 1621-1630页

作者： Shengkun Jia Xing Qian Xigang Yuan Sigurd Skogestad School of chemical engineering and Technology Chemical Engineering Research Center Collaborative Innovation Center of Chemical Science and Engineering (Tianjin)State Key Laboratory of Chemical Engineering Tianjin University Department of chemical engineering Norwegian University of Science and Technology (NTNU)

The focus of this paper is to investigate different control structures(single-loop PI control) for a dividing wall(Petlyuk) column for separating ethanol, n-propanol and n-butanol. Four control structures are studied. All the results are simulations based on Aspen Plus. Control structure 1(CS1) is stabilizing control structure with only temperature controllers. CS2, CS3 and CS4, containing also composition controllers, are introduced to reduce the steady state composition deviations. CS2 adds a distillate composition controller(CCDB) on top of CS1. CS3 is much more complicated with three temperature-composition cascade controllers and in addition a selector to the reboiler duty to control the maximum controller output of light impurity composition control in side stream and bottom impurity control in the prefractionator. CS4 adds another high selector to control the light impurity in the sidestream. Surprisingly, when considering the dynamic and even steady state performance of the proposed control structures, CS1 proves to be the best control structure to handle feed disturbances inserted into the three-product Petlyuk column.

关键词： Distillation columns Automatic process control Computer-aided control system design Petlyuk columns

Multi-functional 3D N-doped TiO2 microspheres used as scattering layers for dye-sensitized solar cells

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Frontiers of chemical science and engineering 2017年第3期11卷 395-404页

作者： Zijian Cui Kaiyue Zhang Guangyu Xing Yaqing Feng Shuxian Meng School of chemical engineering and Technology Tianjin University Tianjin 300350 China collaborative innovation center of chemical science and engineering Tianjin 300350 China

Three-dimensional TiO2 microspheres doped with N were synthesized by a simple single-step solvothermal method and the sample treated for 15 h （hereafter called TMF） was then used as scattering layers in the photoanodes of dye-sensitized solar cells （DSSCs）. The TMF was characterized using scanning electron micro- scopy, high resolution transmission electron microscopy, Brunauer-Emmett-Teller measurements, X-ray diffraction, and X-ray photoelectron spectroscopy. The TMF had a high surface area of 93.2 m2. g-~ which was beneficial for more dye-loading. Five photoanode films with different internal structures were fabricated by printing different numbers of TMF scattering layers on fluorine-doped tin oxide glass. UV-vis diffuse reflection spectra, incident photon-to-current efficiencies, photocurrent-voltage curves and electrochemical impedance spectroscopy were used to investigate the optical and electrochemical proper- ties of these photoanodes in DSSCs. The presence of nitrogen in the TMF changed the TMF microstructure, which led to a higher open circuit voltage and a longer electron lifetime. In addition, the presence of the nitrogen significantly improved the light utilization and photocur- rent. The highest photoelectric conversion efficiency achieved was 8.08%, which is much higher than that derived from typical P25 nanoparticles （6.52%）.

关键词： DSSCs N doping scattering layer electron lifetime

Morphological Studies on Sn-O Coordination Driving Self-assembly of Well-defined Organotin-containing Block Copolymers

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Chinese Journal of Polymer science 2014年第12期32卷 1655-1665页

作者： Jian Jiang Wei Yan 柳凌艳 Wei-xing Chang 李靖 The State Key Laboratory of Elemento-Organic Chemistry Nankai University Collaborative Innovation Center of Chemical Science and Engineering

A tin-oxygen coordination driving self-assembly was developed in the block copolymers containing organotin, which were prepared by the radical addition-fraction transfer（RAFT） method and characterized by the gel-permeation chromatography（GPC） and 1H-NMR. And the self-assemblies of these block copolymers with various chain length ratios in the different concentrations in CHCl3 were stable according to the results of DLS and TEM. Additionally, it was also given an insight investigation on the regulation of self-assembly of the block copolymers by adding dibutyltin dichloride and a possible mechanism was proposed.

关键词： Organotin RAFT Sn-O coordination Self-assembly.

Metal Chlorides Supported Solid Catalysts for F-C Acylations of Arenes

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Transactions of Tianjin University 2015年第5期21卷 400-405页

作者：李阳刘云龙穆曼曼陈立功 School of chemical engineering and Technology Tianjin University collaborative innovation center of chemical science and engineering (Tianjin)

A series of metal chlorides supported solid catalysts were prepared by simple wet impregnation method. Their catalytic performances for Friedel-Crafts acylation of toluene with benzoyl chloride were evaluated and the excellent results were obtained over FeC13/SiO2. These catalysts were characterized by BET, NH3-TPD and FT-IR of pyridine adsorption to clarify the structure-activity relationship. It was found that FeC13/SiO2 has larger pore size and pore volume than other catalysts, which increased the accessibility of the catalyst. In addition, FeC13/SiO2 ex- hibited higher molar ratio of Lewis acid sites and Brtpnsted acid sites, which might be another reason for the in- crease of toluene conversion. Furthermore, the reaction parameters, including temperature, time and molar ratio, were optimized. Under the optimized conditions, 91.2% conversion and 82.0% selectivity were obtained. Mean- while, the generality of the catalyst was demonstrated by the acylations of alkyl substituted aromatics. Finally, the catalyst was reused for four runs with slight loss in catalytic activity, which attributed to the drain of the active component.

关键词： acylation heterogeneous catalyst silica gel ferric chloride