Luận văn thạc sĩ development of novel titanate nanotubes reduced graphene oxide composite for the

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THAI NGUYEN UNIVERSITY

UNIVERSITY OF AGRICULTURAL AND FORESTRY

VU THI HOAI

TOPIC TITLE: DEVELOPMENT OF NOVEL TITANATE NANOTUBES/

REDUCED GRAPHENE OXIDE COMPOSITE FOR THE REMOVAL OF

HEAVY METALS FROM AQUEOUS SOLUTION

BACHELOR THESIS

Study Mode: Full-time

Major: Environmental Science and Management

Faculty: International Training and Development Center

Batch: 2010-2015

Thai Nguyen, 15/01/ 2015

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DOCUMENTATION PAGE WITH ABSTRACT

Thai Nguyen University of Agriculture and Forestry

Degree Program Bachelor of environmental Science and Management

Student name Vu Thi Hoai

Student ID DTN1053110084

Thesis Tiltle

Development of Novel Titanate Nanotubes/ Reduced

Graphene Oxide Composite for the Removal of Heavy

Metals from Aqueous Solution

Supervisor(s)

Prof. Dr. Nguyen The Dang, Thai Nguyen University of

Agriculture and Forestry, Vietnam

Prof. Ruey-an Doong, National Tsing Hua University

Abstract

Graphene oxide (GO), is a two dimensional carbon nano-material which exhibits a

great adsorption potential. Graphene functionalized composites enhance its adsorption

efficiency for toxic heavy-metals from contaminated waste water. Titanium nanotubes

and GO were assembled in basic medium via microwave-assisted hydrothermal

method. The strong anchoring of TNT on the surface of GO sheets can be easily

observed by TEM (Transmission Electron Microscopy), XRD (X-ray Diffraction).

Diffraction on GO sheets confirmed through D-band and G-band ration by Raman

Spectroscopy. As-synthesized TNT/rGO composite shows high efficiency and high

selectivity toward heavy metals in aqueous solution. The results indicated that

TNT/rGO composite with high adsorption efficiency and fast adsorption equilibrium

can be used as a practical adsorbent for heavy metals in aqueous solution.

Keywords

Titanate nanotube, Graphene oxide, composite,

hydrothermal, adsorption

Number of papers 44 pages

Date of submission: 15/01/2015

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ACKNOWLEDGEMENTS

I am deeply indebted to my research supervisor Prof. Ruey-An Doong, whose

stimulating motivations and valuable ideas helped me to complete my thesis and I

would like to offer my sincere gratitude to prof. Dr. Nguyen The Dang for his

support throughout my thesis with his patience and knowledge whilst allowing me the

room to work in my own way. I attribute the level of my Bachelor degree to his

encouragement and effort.

I am grateful to Rama Shanker Sahu (PhD) and Yen-Tung Yang (PhD) for

their valuable help, advices and constructive comments during all my experiments and

writing thesis.

I would like to thank Duncan, Sammy, Joyce (MS) for their great support in

characterizing my samples, YC Ken Tsai (PhD) and Rudy (PhD) for their impressive

help in adsorption studies.

I would also like to thank Khanh, Linh and all FATECOL members,

Biomedical Engineering and Environmental Sciences, National Tsing-Hua University,

Taiwan, who provided their ongoing support, questions and suggestions.

Finally, I would like to express my love and gratitude to my beloved parents for

their support & endless love.

VU THI HOAI

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TABLE OF CONTENTS

LIST OF FIGURES.......................................................................................................1

LIST OF TABLES .........................................................................................................2

LIST OF ABBREVIATIONS.......................................................................................3

PART I. INTRODUCTION..........................................................................................4

1.1. Research rationale..............................................................................................4

1.2. Research's Objectives .........................................................................................6

PART II. LITERATURE REVIEW............................................................................7

2.1. Overview of heavy metals...................................................................................7

2.1.1. Definitions and sources of heavy metals.........................................................7

2.1.2. Characteristics of heavy metals.......................................................................7

2.2. Heavy metal pollution in the world and Vietnam............................................8

2.2.1. In estuary, coastal and marine areas..............................................................8

2.2.2. In acid sulfate soil areas..................................................................................9

2.3. Characteristics and hazards of some heavy metals.......................................10

2.3.1. Arsenic (As)....................................................................................................10

2.3.2. Cadmium (Cd)................................................................................................11

2.3.3. Lead (Pb)........................................................................................................12

2.3.4. Copper (Cu) ...................................................................................................13

2.4. Effects of heavy metal to environmental and human health........................14

2.5. Some of treatment methods for the removal of heavy metals from aqueous

solution.......................................................................................................................15

2.5.1. Carbon materials............................................................................................15

2.5.2. Phytoremediation ...........................................................................................18

2.5.3. Nanomaterials................................................................................................19

2.5.4. Titanate nanotubes.........................................................................................19

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2.6. Overview of handling heavy metals in aqueous solution using Titanate

nanotube / reduced graphene oxide composite. ....................................................20

2.6.1. Scientific Basis of handling heavy metals in aqueous solution by rGO-TNT

composite .................................................................................................................20

2.6.2. Some research results of absorption of heavy metals in water by rGO-TNT

composite .................................................................................................................20

2.6.3. Prospects of technological rGO-TNT composite in removal of heavy metals

in aqueous solution. .................................................................................................21

PART III. METHODS ................................................................................................22

3.1. Materal ...............................................................................................................22

3.1.1. Chemicals.......................................................................................................22

3.1.2. Instruments.....................................................................................................22

3.2. Methods..............................................................................................................23

3.2.1. Synthesis of TNT..........................................................................................23

3.2.2. Synthesis of Graphene oxide .........................................................................24

3.2.3. Synthesis of rGO-TNT Composite................................................................25

3.2.4. Adsorption Experiment..................................................................................25

3.2.5. The method of determining the characteristics of the material ....................27

PART IV. RESULTS...................................................................................................32

4.1. Characterization of GO and titanate nanotubes/rGO composite................32

4.2. Morphology of TNT, GO and rGO-TNT composite.....................................35

4.3. Application into removal of heavy metal ions................................................36

PART V. DISCUSSION AND CONCLUSION.......................................................39

5.1. Discussion ...........................................................................................................39

5.2. Conclusion..........................................................................................................40

REFERENCES.............................................................................................................42

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