학위논문 (석사)-- 서울대학교 대학원 : 융합과학부, 2017. 2. 박원철.A magnetically recoverable photocatalyst was prepared by supporting TiO2 nanoparticles on a superparamagnetic iron oxide nanocluster (SION) core@fibrous silica shell (FSS) nanocomposite. Using the raspberry-shaped magnetic iron oxide nanocluster core as a seed, FSS with uniform thickness was grown directly on the core surface by a sol-gel process. The preparation method was optimized to have a single core for each nanoparticle by adjusting the amount of the silica source. The FSS has a fanning structure of radial pores, which enable large amounts of TiO2 nanoparticles to be supported easily on the pore surface. SION@FSS with amorphous TiO2 loaded on the pores (SION@FSS@Am-TiO2) was crystallized to the anatase phase (SION@FSS@A-TiO2), which shows good photocatalytic effect. When used for water purification, SION@FSS@A-TiO2 shows faster dye degradation kinetics compared to commercial P25 nanoparticles. The as-prepared SION@FSS@A-TiO2 photocatalyst could be magnetically recovered easily from water after decolorization of dye.Chapter 1. Introduction 1
1.1. TiO2 Photocatalyst 1
1.2. Mesoporous silica (MSN) supports 1
1.3. Fibrous silica materials 2
1.3.1. Characteristics and applications 2
1.3.2. Synthesis 3
1.4. Magnetically recoverable photocatalyst 4
1.4.1. Magnetic recollection 4
1.4.2. Superparamagnetic iron oxide nanocluster (SION) core 4
1.4.3. SION Core@Fibrous Silica Shell (FSS) 5
1.4.4. SION@FSS@Anatase TiO2 (A-TiO2) 6
Chapter 2. Experimental 7
2.1. Materials 7
2.2. Preparation of SION 7
2.3. Preparation of SION@FSS 8
2.4. Preparation of SION@FSS@Am-TiO2 and SION@FSS@A-TiO2 9
2.5. FSS thickness control of SION@FSS 11
2.6. Material Characterization 11
2.7. Photodecolorization Test 12
2.8. Recollection and Reusability Test 13
Chapter 3. Result and discussion 14
3.1. Synthetic procedures 14
3.1.1. Overview 14
3.1.2. SION core 15
3.1.3. FSS coating on SION core (SION@FSS) 15
3.1.4. Control of FSS thickness 19
3.1.5. Supporting TiO2 on SION@FSS and crystallization 20
3.1.6. Control of TiO2 amounts 22
3.2. characterization 26
3.2.1. Size and morphology 26
3.2.2. Crystal structure 29
3.2.3. Pore structure analysis 31
3.2.4. Magnetic property 33
3.3. Photodegradation of MetB 35
Chapter 4. Conclusion 42
References 43
요약(국문초록) 48Maste