Trang 17 7 1.2 Classifications, properties and applications of textile dyes chemical structural Azo Textile dyes have been classified according to theirdyes, Nitro dyes, Indigo dyes, Ant
MINISTRY OF EDUCATION AND TRAINING HANOI UNIVERSITY OF SCIENCE AND TECHNOLOGY VŨ VIỆT THẮNG STUDY ON PROCESS DESIGN AND BASIC DESIGN OF A PHOTOCATALYTIC REACTION SYSTEM FOR TREATMENT OF TEXTILE WASTEWATER CHEMICAL ENGINEERING MASTER THESIS OF CHEMICAL ENGINEERING … SUPERVISOR DR TA HONG DUC Hanoi – 2019 Tai ngay!!! Ban co the xoa dong chu nay!!! 17051113887301000000 STATEMENT I hereby declare that all the data in this Master thesis is the results of investigation carried out by me in the Leibniz-Institut für Katalyse, Rostock, Germany, and that all direct and indirect sources are acknowledged as references Hanoi, March 27th, 2019 Vũ Việt Thắng ACKNOWLEDGEMENTS First of all, I would like to express my deepest appreciation to my supervisor, Dr Ta Hong Duc, for pursuing my Master study at School of Chemical Engineering, Hanoi University of Science and Technology, granting me his endless patience, invaluable guidance and consideration at all times I would also like to extend my sincere thanks to Dr Norbert Steinfeldt, Ms Pritzkow, Mr Michael Sebek and my helpful friend, Mr Karl Friedrich Iffländer for all sharing knowledges and research experiences when I was working on my topic at the LeibnizInstitut für Katalyse for six-month stay in Rostock, Germany I really appreciate Prof Dr Le Minh Thang, Dr Dirk Hollmann and Dr Esteban Mejia as the DAAD – ROHAN SDG Schoolarship’s co-ordinator for their helpful support and consideration so that I could have a precious opportunity to go study abroad in Rostock and could complete my thesis Last but not least, I would like to thank my parents for their endless love, support, and patience during all my stay abroad I never thought that I could it without you all Though I cannot list all the names in this section, I feel myself very lucky when I have them, teachers, colleagues, and friends throughout my life CONTENTS STATEMENT LIST OF ABBREVIATIONS AND SYMBOLS USED I LIST OF TABLES II LIST OF FIGURES III INTRODUCTION .1 Chapter LITERATURE REVIEW .2 1.1 Textile operations 1.1.1 Sizing and desizing .4 1.1.2 Bleaching 1.1.3 Mercerization .4 1.1.4 Dyeing and printing 1.1.5 Finishing 1.2 Classifications, properties and applications of textile dyes 1.2.1 Azoic dyes 1.2.2 Reactive dyes 10 1.2.3 Vat dyes 11 1.2.4 Sulphur dyes .12 1.2.5 Acid dyes 13 1.2.6 Disperse dyes 14 1.2.7 Basic dyes 15 1.2.8 Direct dyes .16 1.3 Carbon nitride material review 16 1.3.1 Brief introduction of g-C3N4 18 1.3.2 Electronic structure of g-C3N4 20 1.3.3 Application of g-C3N4 .22 1.3.4 Methods to improve g-C3N4 photocatalytic efficiency .28 Chapter Materials and Methods 33 2.1 Materials 33 2.1.1 Chemicals 33 2.1.2 Catalyst synthesis .33 2.2 Photoreaction apparatus and procedure 34 2.3 Analytical Methods 35 2.3.1 X-ray Diffraction Analysis .35 2.3.2 Attenuated total reflectance - Infrared spectroscopy .35 2.3.3 Brunauer–Emmett–Teller method 35 2.3.4 Scanning transmission electron microscopy 35 2.3.5 UV/Vis spectra 36 Chapter Results and Discussion .37 3.1 Characterization of materials 37 3.1.1 The XRD results .37 3.1.2 The SEM/TEM images 38 3.1.3 The BET method .41 3.1.4 The UV/Vis spectra materials 42 3.1.5 The ATR – IR of catalysts 43 3.1.6 The XPS analytic results 45 3.2 The photocatalytic activities of materials .48 Conclusions and outlook 53 Conclusions .53 Outlook 54 REFERENCES 55 LIST OF ABBREVIATIONS AND SYMBOLS USED ATR Attenuated total reflectance BET Brunauer–Emmett–Teller method ESR Electron spin resonance IR Infrared spectroscopy MO Methyl Orange PL Photoluminescence spectra SEM Scanning electron microscope TEM Transmission electron microscopy XRD X-ray Diffraction UV Ultra violet VIS Visible XPS X-ray photoelectron spectroscopy Fe – gC3N4 Carbon nitride material doping Iron gC3N4 – O Fe – gC3N4 – O Carbon nitride material oxidizing with Hydrogen peroxide Carbon nitride material doping with Iron and oxidizing with Hydrogen peroxide I LIST OF TABLES Table 1.1 Classification and examples of dyes according to the chromophore present [19] Table 1.2 Catalytic activity of mpg-C3N4 in the Friedel–Crafts acylation of benzene [47] 23 Table 3.1 Summary of general characteristics of the different g-C3N4 samples .42 Table 3.2 Near surface composition of the different catalysts determined by XPS 46 II LIST OF FIGURES Figure 1.1 A flow diagram for steps involved in wet processing of fabric .3 Figure 1.2 Dyes for different fibers Figure 1.3 The component of major pollutants involved at various stages of a textile manufacturing industry .6 Figure 1.4 Example of azo dye 10 Figure 1.5 Example of reactive dye (C I Reactive Red 198) 11 Figure 1.6 Chemical structure of vat dyes .12 Figure 1.7 Two sulfur dyes very used 13 Figure 1.8 C I Acid Blue 25 14 Figure 1.9 Chemical structure of C I Disperse Red 15 Figure 1.10 Basis Blue 22 15 Figure 1.11 C I Direct Red 16 Figure 1.12 The schematic diagram of the s-heptazine unit and s-triazine unit structure [45] .19 Figure 1.13 TG-DSC thermograms for heating the melamine [55] 20 Figure 1.14 Postulated condensation of melamine 1a [79] 20 Figure 1.15 Electronic structure of polymeric melon (a) Density-functional-theory band structure for polymeric melon; (b) the Kohn–Sham orbitals for the valence band of polymeric melon; (c) the corresponding conduction band [44] 22 Figure 1.16 (a) Stacked g-C3N4 sheets function as an all-organic solidstatephotocatalyst promoting redox reactions with visible light; (b) chemical interaction of benzene and defective g-C3N4 via HOMO–LUMO hybridization of melem and benzene [99] 24 Figure 1.17 (a) Electron transfer reactions with mpg-C3N4; (b) kinetic isotope effect [108] 25 Figure 1.18 Schematic representation of the oxidation mechanism [111] .26 Figure 1.19 Proposed pathway for the photocatalytic H2 production by [M(TEOA)2]2+/gC3N4 systems [117] 27 III Figure 1.20 Comparison of the XRD spectra of g-C3N4 with those of Fe/g-C 3N4 hybrids with varying Fe contents 30 Figure 1.21 (a, b) Typical TEM images of CNS–CN; (c) high-resolution XPS spectra of S2p recorded from CN, CNS–CN and CNS; (d) room temperature EPR spectra of CNS–CN Arrow direction in (d): CN, CNS–CN-1, CNS–CN-2, CNS–CN-3, CNS– CN-4; (e) schematic illustration of organic heterojunction formed between CN and CNS D = donor [136] 31 Figure 2.1 The photocatalytic testing system 34 Figure 3.1 XRD pattern of the prepared g-C3N4 – samples which differ in composition and/or post-treatment (* - Fe3 O4 phase) .37 Figure 3.2 SEM images of the prepared g-C 3N4 – materials: g-C3N4 (a,b); g-C3N4 – O (c,d); Fe – g-C3N4 (e,h) and Fe – g-C3N4 – O (g,h)………………………………39 Figure 3.3 HAADF_STEM images of g-C3N4 - O (a,b) and Fe – g C 3N4 – O (c,d) with different magnification……………………………………………………… 40 Figure 3.4 a) N2 adsorption-desorption isotherms for the different samples and b) BJH pore size-distribution………………………………………………………….41 Figure 3.5 a) UV-Vis spectra and b) Tauc plots from the spectra of the all g-C3N4 – samples…………………………………………………………………………… 43 Figure 3.6 ATR-IR spectra of the different g-C 3N4 – samples…………………….44 Figure 3.7 XPS spectra (C1s, N1s, O1s and Fe2p) of different catalysts: pure g-C3N4, g-C3N4-O, Fe-gC3N4, and Fe-gC3N4-O…………………………………………… 45 Figure 3.8 ESR spectra of A) g-C3N4 and g-C3N4-O and B) Fe-g-C 3N4 and Fe-gC3N4O (10 mg, 298 K)………………………………………………………………… 47 Figure 3.9 The UV-Vis spectra of MO degradation process: (a) no catalyst; (b) gC3N4; (c) Fe – g-C 3N4; (d) g-C 3N4 – O; (e) Fe – g-C3N4 – O and (f) the HPLC determination………………………………………………………………………50 Figure 3.10 The PL spectra of g-C3N4 based materials……………………………51 IV