광촉매 활성을 위한 Fe3O4@TiO2-M(M = Ag,Au)의 합성 및 응용
Synthesis and Applications of Fe3O4@TiO2-M(M = Ag,Au) for Photocatalytic Activity
초록/요약 도움말
지속적인 과학 발달에 의해 깨끗하고 쾌적한 환경의 필요성이 시급해지고 있으며, 폐수의 오염 물질을 줄이기 위한 효율적이면서 저비용의 정화 기술이 필요로 하게 되었다. TiO2는 무독성, 생물학적으로 불활성, 화학적 안정성 및 저비용으로서 광촉매에 적합한 물질 중 하나로 간주된다. 또한 자성체인 Fe3O4입자는 광촉매 물질의 손쉬운 회수와 재활용성을 위해 core로 사용되어 core-shell 구조를 형성하였다. 이번 연구에서는 Ag 또는 Ag,Au가 코팅된 Fe3O4@TiO2 core-shell 입자의 손쉽고 효율적인 합성방법을 제시한다. Fe3O4@TiO2–Ag,Au는 자성체로 인한 손쉬운 분리가 가능하여 광촉매의 단점을 보완시켰고, 비표면적을 증가시키는 방안과 귀금속인 Ag와 Au의 코팅에 의해 향상된 광촉매 효율을 확인하였다. 합성한 복합체들은 FE-SEM, HR-TEM, XRD에 의해 표면적 형상과 결정구조를 측정하였고, Ag 또는 Ag,Au가 코팅된 Fe3O4@TiO2 입자의 크기 분포를 확인하였다. 이 광촉매는 태양광 또는 가시광선 하에서 Rhodamine B를 빠른 시간 내에 분해하여 높은 광촉매 효율을 보였다. 마지막으로 Ag 또는 Ag,Au가 코팅된 Fe3O4@TiO2의 광역학적 프로세스는 반응 산소 종(ROS)을 신속하게 생성한다. 따라서 광촉매 반응에서 hydrogen peroxide (H2O2), hydroxyl radical (·OH)과 마지막으로 singlet oxygen (1O2)과 같은 고유 반응 산소 종(ROS)의 검출 방법과 생성 메커니즘을 종합적으로 조사하였다.
more초록/요약 도움말
With a growing demand for comfortable environment, purification technologies with high efficiency and low cost to reduce the pollutant contents of wastewater are urgently needed. TiO2 is considered to be one of the suitable materials for photocatalyst due to its nontoxicity, biological inertness, chemical stability and low cost. In addition, magnetic Fe3O4 particles have been introduced to functionalize core-shell particles due to their unique separable feature that makes it possible for convenient recycling of novel metals. In this study, a facile and efficient approach for fabricating Ag or Ag,Au-coated Fe3O4@TiO2 particles with a good core-shell structure is demonstrated. The Fe3O4@TiO2-Ag,Au core-shell microspheres possesses a relatively large specific surface area induced by noble metal nanoparticles, magnetic behavior for easy reuse, and enhanced photocatalytic efficiency caused by metal semiconductor charge transfer or energy transfer. As characterized by FE-SEM, HR-TEM and XRD, the as-synthesized Ag or Ag,Au-coated Fe3O4@TiO2 nanoparticles exhibit a narrow size distribution. The Ag or Ag,Au-coated Fe3O4@TiO2 photocatalyst exhibited high photocatalytic activity in the degradation of Rhodamine B under solar light and visible light. Finally, the phorodynamic process of Ag or Ag,Au-coated Fe3O4@TiO2 rapidly generates reactive oxygen species (ROS). Therefore, the detection methods and generation mechanisms of the intrinsic reactive oxygen species (ROS) such as hydrogen peroxide (H2O2), hydroxyl radical (·OH) and singlet oxygen (1O2) in photocatalysis were comprehensively examined. Reactive oxygen species (ROS) confirmed once more under the presence of scavengers.
more목차 도움말
국문 초록··························································································1
영문 초록··························································································2
Ⅰ.서론····························································································4
1.나노구조의 TiO2····································································4
1.1.나노구조의 TiO2 특성··················································4
1.2.나노구조의 TiO2 응용··················································5
2.복합체 형태의 광촉매····························································6
3.광촉매 응용 연구···································································9
Ⅱ.실험····························································································15
1.기구 및 시약·········································································15
2.Fe3O4 자성 나노입자 합성······················································17
2.1.Fe3O4 자성 나노입자 500nm 합성································17
2.2.Fe3O4 자성 나노입자 200nm 합성································18
3.Fe3O4@TiO2 core-shell 자성 나노입자 합성···························19
4.Fe3O4@TiO2-Ag core-shell 자성 나노입자 합성·····················20
5.Fe3O4@TiO2-Ag,Au core-shell 자성 나노입자 합성················20
6.Fe3O4@TiO2-M core-shell 자성 나노입자의 광촉매 응용 실험 ···22
7.Fe3O4@TiO2-M core-shell 자성 나노입자의 ROS 측정 실험···23
7.1.Singlet oxygen (1O2) 측정 실험···································23
7.2.Hydrogen peroxide (H2O2) 측정 실험··························24
7.3.Hydroxyl radical (·OH) 측정 실험······························25
8.Fe3O4@TiO2-M core-shell 자성 나노입자의 ROS 제거 실험···26
8.1.Singlet oxygen (1O2) 제거 실험···································26
8.2.Hydroxyl radical (·OH) 제거 실험······························27
9.Fe3O4@TiO2-M core-shell 자성 나노입자의 ROS 간섭 실험···28
9.1.Singlet oxygen (1O2) 간섭 실험···································28
9.2.Hydrogen peroxide (H2O2) 간섭 실험··························29
Ⅲ.결과 및 고찰···············································································30
1. Fe3O4 자성 나노입자의 구조 및 특성 분석······························30
2.Fe3O4@TiO2 core-shell 자성 나노입자 구조 및 특성 분석······33
3.Fe3O4@TiO2-Ag core-shell 자성 나노입자 구조 및 특성 분석 ···36
4.Fe3O4@TiO2-Ag,Au core-shell 자성 나노입자 구조 및 특성 분석 39
5.Fe3O4@TiO2-M core-shell 자성 나노입자의 광촉매 응용 분석 ···44
6.Fe3O4@TiO2-M core-shell 자성 나노입자의 ROS 실험···········51
6.1.ROS 측정 실험····························································51
6.2.ROS 제거 실험····························································58
6.3.ROS 간섭 실험····························································60
Ⅳ.결론····························································································62
Ⅴ.참고문헌······················································································64
