MINISTRY OF EDUCATION AND TRAINING HANOI UNIVERSITY OF SCIENCE AND TECHNOLOGY Nguyen Trung Hieu RESEARCH INTO TiO2/AC, TiO2/GO SYNTHESIS AND COATING ON CORDIERITE CERAMIC APPLIED AS CATALYSTS FOR PHOTODEGRADATION OF METHYL ORANGE AND PHENOL DOCTORAL DISSERTATION IN CHEMICAL ENGINEERING Hanoi – 2022 MINISTRY OF EDUCATION AND TRAINING HANOI UNIVERSITY OF SCIENCE AND TECHNOLOGY Nguyen Trung Hieu RESEARCH INTO TiO2/AC, TiO2/GO SYNTHESIS AND COATING ON CORDIERITE CERAMIC APPLIED AS CATALYSTS FOR PHOTODEGRADATION OF METHYL ORANGE AND PHENOL Major : Chemical Engineering Code No : 9520301 DOCTORAL DISSERTATION IN CHEMICAL ENGINEERING ADVISOR: Prof. Le Minh Thang Hanoi – 2022 GUARANTEE The study has been conducted at the School of Chemical Engineering (SCE), Germany and Vietnam catalyst research center (Gevicat), Hanoi University of Science and Technology (HUST). I affirm that this is my own research. The co-authors consented to the use of all the data and findings presented in the thesis and confirmed their veracity.
This study has not been published by anybody but me. Hanoi, Octorber 25th 2022 Thesis Advisor PhD student Prof. Le Minh Thang Nguyen Trung Hieu i ACKNOWLEDGEMENTS I would like to express my sincerest and heartfelt gratitude to the following people and organizations whose valuable contributions and assistances have made my research possible: To Hanoi University of Science and Technology, specifically to the School of Chemical Engineering, Department of Organic and Petrochemical Technology for providing the laboratory instruments and the equipment for me to accomplish my research. To - Catalyst Program, for letting me be an official member of the sponsored research on modified TiO2 synthesis and methyl orange and phenol photocatalytic degradation at Hanoi University (HUST) and National Taiwan University (NTU).
To my thesis adviser, Prof. Le Minh Thang, for giving me guidance and supervision as well as critiques and comments on my progress reports to bring me patience, finance, and power to finish this research. Jeffrey Chi-Sheng Wu, for allowing me to be a part of his research team under the RoHan Program and for training me in his Lab at NTU. To my family and friends who always try to encourage and motivate me during my thesis course, especially since it is the late gift for my father in heaven now.
ii TABLE OF CONTENTS GUARANTEE. ii TABLE OF CONTENTS. iii LIST OF ABREVIATIONS.vi LIST OF TABLES. vii LIST OF FIGURES.
Necessity of the study. Objectives of the study. Content of the thesis. Methodologies of the study.
Scope of the study. Scientific and practical meanings. Novelty of the study .Structure of the thesis. Textile industry and Methyl Orange dye.
Phenol in industry and its impact to the health. Titanium dioxide, TiO2. Principles of Precipitation, sol-gel and hydrothermal synthesis methods 13 1. Preparation of photocatalyst using sol-gel method.
Support and thin films .1 Overview of Cordierite .2 Mesoporous TiO2 and coating techniques .3 Catalyst Suspension and immobilization.6 TiO2/AC Materials .8 TiO2/GO Materials .9 MO photocatalytic degradation .10 Phenol photocatalysis degradation .38 iii CHAPTER 2 EXPERIMENTS .1 Materials and instruments .1 Synthesis of mesoporous TiO2. Synthesis of TiO2 and AC/TiO2 by Sol-gel method. Synthesis of TiO2 GO by sol-gel method. Synthesis of TiO2 films on cordierite .3 Characterization of the catalysts .1 Morphology on the surface.
Elemental surface composition and traces of impurities .3 Specific surface area, pore volume, and average pore size .4 Crystal structures formed and the crystallite diameter. UV-Vis DSR. High-performance liquid chromatography analysis .4 Experimental set up. To calculate the efficiency of photocatalytic process .1 Construct calibration curve of methyl orange solution.2 Calculation the concentration via equation.64 CHAPTER 3 RESULTS AND DISSCUSSIONS.
Mesoporous TiO2 synthesized by precipitation and hydrothermal with CTAB and P123 surfactants. MO photocatalytic degradation of mesoporous TiO2 photocatalysts prepared by precipitation and hydrothermal methods with surfactants (CTAB and P123). TiO2/AC catalyst synthesized using sol-gel method. Photocatalytic activity of the MO in water.
GO-TiO2 catalysts by sol-gel method .2 MO photocatalytic degradation by TiO2 – GO. TiO2 films on Cordierite. TiO2 nanocatalysts thin film by the CVD method on various substrates100 3. Phenol photocatalytic degradation .107 CHAPTER 4: CONCLUSIONS AND RECOMENDATONS .116 v LIST OF ABREVIATIONS Symbols Meaning UV Ultraviolet radiation MO methyl orange GO graphene oxide FTIR Fourier transform infrared spectroscopy SEM Scanning electron microscopy FE SEM Field Emission EDX Energy-dispersive X-ray spectroscopy P123 poly(ethylene glycol)-block-poly(propylene glycol)-block-poly (ethylene glycol) CNT carbon nanotube LPMOCVD Low pressure chemical vapor deposition AC activated carbon TTIP titanium tetraisopropoxide UV–VIS Ultraviolet- Visible HPLC High-performance liquid chromatography XRD X-ray diffraction BET Brunauer, Emmett and Teller SEM Scanning electron microscopy CTAB cetyl trimethyl ammonium bromide PEG polyethylene glycol vi LIST OF TABLES Table 1.
The General Mechanism of the Photocatalytic Reaction Process on TiO2 [49]. Summary of TiO2 and GO composites used as photocatalyst .1: List of chemicals .2: List of main instruments .3: Catalyst synthesized by hydrothermal and precipitation methods using surfactant.4 : AC to TiO2 Ratio with Corresponding Theoretical % Weight AC in AC/TiO2 catalyst .5: Catalysis films and powders synthesized by various methods with the low concetration of PEG.6: Catalyst films and powders synthesized by various methods with higher concentration of PEG.1: The surface characteristics of catalysts synthesized by hydrothermal and precipitation methods .2: Crystalline sizes of catalysts .3: Surface area of two samples by sol-gel synthesis .4: Crystalline sizes of catalysts .5: Surface area of GO-TiO2 catalysts .6: Crystalline sizes of catalysts .7: Effect of ratio mol TTIP:H2O to the catalyst mass coated .8: Catalysts films coated cordierite .9: Apparent first-order rate constant kapp and correlation coefficient R2 for phenol degradation by catalysts synthesized by various methods .10: Apparent first-order rate constant kapp and correlation coefficient R2 for phenol degradation with various initial concentrations by P123-C25-450 catalyst .11: Apparent first-order rate constant kapp and correlation coefficient R2 for phenol degradation by P123-C25-450 catalyst with various concentrations H2O2 .12: Apparent first-order rate constant kapp and correlation coefficient R2 for phenol degradation in visible light condition .113 vii LIST OF FIGURES Fig.1: Chemical structure of MO molecule [33,34] .2: TiO2 Crystal Structures[44] .3: The mechanism of photocatalytic activity of TiO2 [50] .4: Nanocrystalline Metal Oxide Preparation using Sol-Gel method .5: Structures of graphene, C60, CNT and graphite [109] .6: Structure of GO [110] .7: Possible mechanism of MO with TiO2 [142] .8: Production Distributions from Phenol Decomposition Reaction [152]. Flowchart of TiO2 synthesis using CTAB. Flowchart of TiO2 synthesis using P123.3: Flowchart of GO synthesis .4: Flowchart of GO-TiO2 (GO-ZnO) synthesis .5: Dip-coating TiO2 on the surface of cordierite.6: Experimental LPCVD set-up.7: Simplified internal structure of FESEM.8: Energy band diagram of a semiconductor (Zeghbroeck, 2007).9: Principle diagram of a HPLC system.10a: Photocatalytic exerimental setup with UV-C lamp .10 b: Principle diagram of visible photocatalytic exerimental setup.1: Nitrogen isotherm of CTAB-NE and P123 C25-450.2: Pore size distribution of CTAB-NE and P123 C25-450.3: XRD paterns of catalysts synthesized with surfactants CTAB and P123 .4: FE-SEM images of CTAB-H (a) and P123 C25-450 (b).5: Evaluation of the catalysts using CTAB by two hydrothermal and precipitation methods .6: The influence of citric acid amount to catalyst performance .7:The influence of Ethanol elimination method to catalyst performance .8: Comparing the best catalyst via hydrothermal and precipitation .9: Nitrogen isotherm of SG TiO2 and SG AC1200 TiO2 1/18 .10: Pore size distribution of SG TiO2 and SG AC1200 TiO2 1/18.11: Morphology of SG AC-1200/Ti 1/18 (a) and SG AC-1200/Ti 3/1 (b) .12: EDX analysis results of samples: SG AC-1200/Ti 1/18 (a); SG AC-1200/Ti 2/1 (b);.13: XRD result of AC TiO2 catalysts .14: MO dark adsorption of AC.15: MO photodegration is affected by activated carbon category.16: MO photodegradation via time of catalyst samples at pH=7.17: MO photodegrdation of samples at pH= 4.18: MO photodegradation of samples at pH= 10.19: Comparison the MO photodegradation SG AC1200 Ti/1/18 by pH.20: Nitrogen isotherm of G1/4, G1/18, G1/24.21: Pore distribution of SGGO Ti1/4, SG GO Ti1/18,SG GO Ti1/24 .22: XRD analysis of GO catalyst.23: The effect of GO content to MO photocatalytic degradation .24: Photodegradation of TiO2 GO catalysts with MO concentration 20 ppm in the full range Xenon lamp .25 Photodegradation of SG GO Ti/ 1/18 MO for various concentration .26: (a) SEM Cor-gel-200 and (b) SEM Cor-gel-CTAB .27: Investigate the efficiency of catalyst thin films by dip coating with low concentration of PEG .28: SEM characterization: (a) Cor-CTAB, (b) Corgel 200 (c) Cor-P123.29: SEM characterization of 2 samples Corgel-150AC (a) and Cor-P123 (b) after the first reaction.30: The photocatalytic degradation of four samples Corgel-150, Corgel-150AC, Corgel-200 and AC-gel powder .31: Surface of Corgel-150 (left) and Corgel-150AC (right) after reaction .33: Photocatalytic performance of-P123 and Cor-P123 samples .34: MO Photodegradation by CTAB powder and Cor-CTAB.35: MO Photodegradation with three TiO2 films coated on cordierite .36: The TiO2 film performance in the first and second times.37: SEM characterization of TiO2 on the surface of (a) glass, (b) aluminium, (c) cordierite with 25,000 magnification; SEM characterization of TiO2 on the surface of ix (d) glass, (e) aluminum and (f) ceramic with 100,000 magnification.
EDS characterization of TiO2 on the surface (g) glass, (h) aluminum and (i) c cordierite.38: 10x Microscopy of TiO2 (a) 120oC; (b) 150oC; (c) 200oC; (d) 250oC; (e) 300oC.39: 10x Microscopy of TiO2 thin film on glass substrate at 580 mm-bar pressure at position opposite (a) and next (b) nozzle.40: 10x Microscopy of TiO2 thin film on glass substrate at 700 mm-bar pressure at position opposite (a) and next (b) nozzle.41: 10x Microscopy of TiO2 thin film on glass substrate with carrying gas N2 300 ml/min.42: Visual image of TiO2 thin film on various substrates.43: 10x Microscopy of TiO2 thin film on various substrates .44: TiO2 thin film performance for MO photodegradation with UV-C.45: TiO2 thin film performance for MO photodegradation with full range lamp .46: Phenol degradation evaluation and kinetics study in UV light.47: Effect of the initial concentration to the phenol degradation in UV condition and kinetics study by P123-C25-450 .48: Effect of H2O2 loading and kinetics study in phenol degradation process.49: Phenol degradation process and kinetics study in visible light. Necessity of the study Soil and groundwater resource pollution are serious concerns in our nation. One of the unavoidable effects of uncoordinated economic zone growth is the contamination of water sources with heavy metals and harmful, persistent organic compounds such as phenol and its derivatives. The primary sources of phenol and phenol polluting compounds are the manufacture of synthetic plastics, insecticides, paints, and petroleum [1].
Additionally, the textile sector emits a significant number of harmful chemical compounds into the atmosphere, including azo-based dyes, one of which is methyl orange. As a result, the remediation of contaminated environments with two chemical compounds as phenol and methyl orange, is a hot topic not only in the nation, but also globally. Historically, remediation of polluted water has been mostly dependent on physicochemical and biological treatment approaches. Among these, adsorption is one of the most frequently used strategies for treating chemical contaminants in water due to its ease of use and the broad application of a variety of adsorbents.
Another workable solution is biological treatment, which may eliminate around 90% of organic debris entirely. However, this procedure is less efficient for compounds that are difficult to decompose, such as phenol and methyl orange. Numerous extensive research studies have been undertaken to process the aforementioned chemicals, which include electrochemical methods, ion exchange, ozone, and adsorption on activated carbon [2, 3]. In the other hand, these approaches are rarely used in reality due to their inherent constraints, which include heavy equipment systems, complex operation techniques, high initial and ongoing expenditures, and birth abnormalities.
It must include a sludge post-treatment step, otherwise the efficiency will remain poor results. Using photocatalysts to treat polluted water is one of the most environmentally friendly green treatment methods available, since it employs natural solar energy and is capable of degrading organic contaminants that are difficult to decompose. Without the addition of extra chemicals or sludge buildup in the treatment system [4].