Titanate nanowires doping graphitic carbon nitride nanosheets enhanced visible light photoactivity

THAI NGUYEN UNIVERSITY

UNIVERSITY OF AGRICULTURAL AND FORESTRY

NGUYEN HOANG NAM

TITANATE NANOWIRES DOPING GRAPHITIC CARBON NITRIDE

NANOSHEETS ENHANCED VISIBLE LIGHT PHOTOACTIVITY

FOR SULFAMETHOXAZOLE DEGRADATION

BACHELOR THESIS

Study Mode : Full-time

Major : Environmental Science and Management

Faculty : Advanced Education Program Office

Batch : 2014-2018

Thai Nguyen, 25/9/2018

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Thai Nguyen University of Agriculture and Forestry

Degree Program Bachelor of Environmental Science and Management

Student name Nguyen Hoang Nam

Student ID DTN1454290020

Thesis Title

Titanate nanowires doping graphitic carbon nitride nanosheets

enhanced visible light photoactivity for sulfamthoxazole

degradation

Supervisor(s)

- Prof. Ruey-an Doong, National Chiao Tung University,

Taiwan

- Prof. Phan Dinh Binh, Thai Nguyen University of

Agriculture and Forestry, Vietnam

Supervisor’s

signature

Abstract

The presence of antibiotics in water bodies has received great attention since

they are continuously introduced and detected in the environment and may cause

unpredictable environmental hazards and risks. Herein, Titanate nanowires (TNWs)

decorated graphitic carbon nitride (g-C3N4) nanosheets has been successfully

synthesized by a facile hydrothermal–assisted thermal polymerization approach for

the degradation of sulfamethoxazole (SMX). TNWs are a promising material for

photocatalytic applications such as hydrogen production, solar cells, water splitting

and environmental treatment through the degradation of organic pollutants. In

addition the chemical and thermal stability, low cost, nontoxicity and high

photocatalytic activity of TNWs. This promise reflects the advantageous photo

physical efficacy. The g-C3N4 nanosheets, possess the suitable band gap as a

photocatalyst, however the addition of TNWs on the surface and intercalated layers

of g-C3N4 can enhance the photocatalytic degradation of organic pollutants. The as￾prepared g-C3N4/TNWs photocatalysts were characterized by X-Ray diffraction

(XRD), Scanning Electronic Microscope (SEM), Transmission electron microscopy

(TEM), UV-visible Spectrophotometer (UV-vis), Thermogravimetric Analysis

(TGA), Brunauer-Emmett-Teller (BET). The results showed that g-C3N4 and TNWs

were successfully fabricated under optimal conditions. The photocatalytic

performances of g-C3N4/TNWs nanocomposites were investigated for the

degradation of Sulfamethoxazole (SMX) under visible light irradiation. The

calcination temperature and the g-C3N4 ratio to TNWs are two important factors

which enhance the SMX degradation. 1:8 weight percentages of bulk g-C3N4 and

TNWs polymerized at 500 °C under N2 atmosphere shows the best SMX

degradation rate and reached to 60 % in 2 h incubation time. The enhanced

photocatalytic performances could be mainly attributed to the modified band gap

structure of g-C3N4/TNWs. We expect that the g-C3N4/TNWs nanocomposites in

specific fabrication ratios can serve as supervisor photocatalysts for antibiotics

degradation under visible light.

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Keywords

Titanate nanowires, g-C3N4 nanosheets,

Photodegradation, Sulfamethoxazole, Antibiotics, Visible

light, photocatalytic, degradation,

Number of papers 40 pages

Date of submission 25th

September, 2018

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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 Prof. Phan Dinh Binh for

his support throughout my thesis with his patience and knowledge whilst

allowing me the room to work in my own way.

My special thanks go to Mrs. Duong Thi Ngoc Anh (MSc) about the

help dedicated of his during my studies and research in this laboratory. She was

hearted guidance, given the comments and the orientation in my experiment

steps as well as the process of writing my report.

I would like to thank Jim, Micheal, Sharon, Luong and Ruben for their

guidance to use a variety of important machinery serving my experiment, David

and Bin for their impressive help in perform analysis of TEM and XRD samples

I would also like to thank all members ofthe ECCL Lab, Institute of

Environmental Engineering, National Chiao Tung University, Taiwan, who

provided their ongoing support, questions and suggestions.

Finally, I would like to express to my classmates and gratitude to my

beloved parents, their always support me during the time I study in Taiwan.

Student

Nguyen Hoang Nam

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TABLE OF CONTENTS

LIST OF FIGURES ................................................................................................................ vi

LIST OF TABLES ................................................................................................................ viii

LIST OF ABBREVATIONS .................................................................................................. ix

PART I. INTRODUCTION .................................................................................................... 1

1.1. Research rationale.................................................................................................... 1

1.2. Research objective ................................................................................................... 2

1.3. Research questions................................................................................................... 3

1.4. Limitations............................................................................................................... 3

1.5. Definitions................................................................................................................ 3

PART II. LITERATURE REVIEW....................................................................................... 5

2.1. Overview of Titanate nanowires............................................................................. 5

2.1.1. Titanium oxidation structures and properties ....................................................... 5

2.1.2. Titanate nanowires............................................................................................... 5

2.1.3. The photocatalytic activity of Titanate nanowires.............................................. 6

2.2. Overview of Graphitic carbon nitride nanosheets ................................................... 7

2.2.1. Graphitic carbon nitride nanosheets structures and properties............................. 7

2.2.2. Graphitic carbon nitride nanosheets highlights and limitations ........................... 9

2.2.3. Application of Graphitic carbon nitride nanosheets............................................. 9

2.3. Overview of g-C3N4/ TNWs nanocomposites....................................................... 10

2.3.1. g-C3N4/ TNWs nanocomposites properties ........................................................ 10

2.3.2. Fabrication of g-C3N4/ TNWs nanocomposites.................................................. 10

2.4. Overview of sulfamethoxazole .............................................................................. 11

2.5. Overview of research and application of nanomaterial ......................................... 14